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curl(1)                           curl Manual                          curl(1)




NAME

       curl - transfer a URL


SYNOPSIS

       curl [options / URLs]


DESCRIPTION

       curl  is  a tool for transferring data from or to a server. It supports
       these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS,  HTTP,  HTTPS,
       IMAP,  IMAPS,  LDAP,  LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP,
       SFTP, SMB, SMBS, SMTP, SMTPS, TELNET or TFTP. The command  is  designed
       to work without user interaction.

       curl offers a busload of useful tricks like proxy support, user authen-
       tication, FTP upload, HTTP post, SSL connections, cookies, file  trans-
       fer resume and more. As you will see below, the number of features will
       make your head spin!

       curl is powered by  libcurl  for  all  transfer-related  features.  See
       libcurl(3) for details.


URL

       The  URL  syntax is protocol-dependent. You find a detailed description
       in RFC 3986.

       You can specify multiple URLs or parts of URLs  by  writing  part  sets
       within braces and quoting the URL as in:

         "http://site.{one,two,three}.com"

       or you can get sequences of alphanumeric series by using [] as in:

         "ftp://ftp.example.com/file[1-100].txt"

         "ftp://ftp.example.com/file[001-100].txt"    (with leading zeros)

         "ftp://ftp.example.com/file[a-z].txt"

       Nested  sequences  are not supported, but you can use several ones next
       to each other:

         "http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html"

       You can specify any amount of URLs on the command line.  They  will  be
       fetched  in a sequential manner in the specified order. You can specify
       command line options and URLs mixed and in any  order  on  the  command
       line.

       You  can  specify a step counter for the ranges to get every Nth number
       or letter:

         "http://example.com/file[1-100:10].txt"

         "http://example.com/file[a-z:2].txt"

       When using [] or {} sequences when invoked from a command line  prompt,
       you probably have to put the full URL within double quotes to avoid the
       shell from interfering with it. This also  goes  for  other  characters
       treated special, like for example '&', '?' and '*'.

       Provide  the IPv6 zone index in the URL with an escaped percentage sign
       and the interface name. Like in

         "http://[fe80::3%25eth0]/"

       If you specify URL without protocol:// prefix,  curl  will  attempt  to
       guess  what  protocol  you might want. It will then default to HTTP but
       try other protocols based on often-used host name prefixes.  For  exam-
       ple,  for  host names starting with "ftp." curl will assume you want to
       speak FTP.

       curl will do its best to use what you pass to it as a URL.  It  is  not
       trying  to  validate it as a syntactically correct URL by any means but
       is instead very liberal with what it accepts.

       curl will attempt to re-use connections for multiple file transfers, so
       that  getting many files from the same server will not do multiple con-
       nects / handshakes. This improves speed. Of course this is only done on
       files  specified  on  a  single command line and cannot be used between
       separate curl invocations.


OUTPUT

       If not told otherwise, curl writes the received data to stdout. It  can
       be  instructed  to  instead save that data into a local file, using the
       -o, --output or -O, --remote-name options. If curl  is  given  multiple
       URLs  to  transfer  on  the  command  line, it similarly needs multiple
       options for where to save them.

       curl does not parse or otherwise "understand" the content  it  gets  or
       writes  as  output.  It does no encoding or decoding, unless explicitly
       asked to with dedicated command line options.


PROTOCOLS

       curl supports numerous protocols, or put in URL  terms:  schemes.  Your
       particular build may not support them all.

       DICT   Lets you lookup words using online dictionaries.

       FILE   Read  or  write  local  files.  curl  does not support accessing
              file:// URL remotely, but  when  running  on  Microsoft  Windows
              using the native UNC approach will work.

       FTP(S) curl  supports  the  File Transfer Protocol with a lot of tweaks
              and levers. With or without using TLS.

       GOPHER(S)
              Retrieve files.

       HTTP(S)
              curl supports HTTP with numerous options and variations. It  can
              speak  HTTP  version  0.9,  1.0, 1.1, 2 and 3 depending on build
              options and the correct command line options.

       IMAP(S)
              Using the mail reading protocol, curl can "download" emails  for
              you. With or without using TLS.

       LDAP(S)
              curl can do directory lookups for you, with or without TLS.

       MQTT   curl supports MQTT version 3. Downloading over MQTT equals "sub-
              scribe" to a topic while uploading/posting equals "publish" on a
              topic. MQTT over TLS is not supported (yet).

       POP3(S)
              Downloading  from  a  pop3  server means getting a mail. With or
              without using TLS.

       RTMP(S)
              The Realtime Messaging Protocol  is  primarily  used  to  server
              streaming media and curl can download it.

       RTSP   curl supports RTSP 1.0 downloads.

       SCP    curl supports SSH version 2 scp transfers.

       SFTP   curl supports SFTP (draft 5) done over SSH version 2.

       SMB(S) curl supports SMB version 1 for upload and download.

       SMTP(S)
              Uploading  contents  to  an  SMTP server means sending an email.
              With or without TLS.

       TELNET Telling curl to fetch a telnet URL starts an interactive session
              where  it  sends  what  it  reads  on stdin and outputs what the
              server sends it.

       TFTP   curl can do TFTP downloads and uploads.


PROGRESS METER

       curl normally displays a progress meter during  operations,  indicating
       the  amount  of  transferred  data,  transfer speeds and estimated time
       left, etc. The progress meter displays number of bytes and  the  speeds
       are  in  bytes per second. The suffixes (k, M, G, T, P) are 1024 based.
       For example 1k is 1024 bytes. 1M is 1048576 bytes.

       curl displays this data to the terminal by default, so  if  you  invoke
       curl  to do an operation and it is about to write data to the terminal,
       it disables the progress meter as otherwise it would mess up the output
       mixing progress meter and response data.

       If you want a progress meter for HTTP POST or PUT requests, you need to
       redirect the response output to a file, using shell redirect  (>),  -o,
       --output or similar.

       This  does  not apply to FTP upload as that operation does not spit out
       any response data to the terminal.

       If you prefer a progress  "bar"  instead  of  the  regular  meter,  -#,
       --progress-bar  is your friend. You can also disable the progress meter
       completely with the -s, --silent option.


OPTIONS

       Options start with one or two dashes. Many of the  options  require  an
       additional value next to them.

       The  short  "single-dash"  form  of the options, -d for example, may be
       used with or without a space between it and its value, although a space
       is a recommended separator. The long "double-dash" form, -d, --data for
       example, requires a space between it and its value.

       Short version options that do not need any  additional  values  can  be
       used  immediately  next to each other, like for example you can specify
       all the options -O, -L and -v at once as -OLv.

       In general, all boolean options are enabled with --option and yet again
       disabled  with --no-option. That is, you use the exact same option name
       but prefix it with "no-". However, in this list we mostly only list and
       show the --option version of them.

       --abstract-unix-socket <path>
              (HTTP)  Connect  through an abstract Unix domain socket, instead
              of using the network.   Note:  netstat  shows  the  path  of  an
              abstract  socket  prefixed with '@', however the <path> argument
              should not have this leading character.

              Example:
               curl --abstract-unix-socket socketpath https://example.com

              Added in 7.53.0.

       --alt-svc <file name>
              (HTTPS) This option enables the alt-svc parser in curl.  If  the
              file name points to an existing alt-svc cache file, that will be
              used. After a completed transfer, the cache will be saved to the
              file name again if it has been modified.

              Specify a "" file name (zero length) to avoid loading/saving and
              make curl just handle the cache in memory.

              If this option is used several times, curl  will  load  contents
              from all the files but the last one will be used for saving.

              Example:
               curl --alt-svc svc.txt https://example.com

              Added in 7.64.1.

       --anyauth
              (HTTP) Tells curl to figure out authentication method by itself,
              and use the most secure one the remote site claims  to  support.
              This is done by first doing a request and checking the response-
              headers, thus possibly inducing  an  extra  network  round-trip.
              This  is  used  instead  of  setting  a  specific authentication
              method, which you can do with  --basic,  --digest,  --ntlm,  and
              --negotiate.

              Using --anyauth is not recommended if you do uploads from stdin,
              since it may require data to be sent twice and then  the  client
              must  be able to rewind. If the need should arise when uploading
              from stdin, the upload operation will fail.

              Used together with -u, --user.

              Example:
               curl --anyauth --user me:pwd https://example.com

              See also --proxy-anyauth, --basic and --digest.

       -a, --append
              (FTP SFTP) When used in an upload, this makes curl append to the
              target  file  instead of overwriting it. If the remote file does
              not exist, it will be created.  Note that this flag  is  ignored
              by some SFTP servers (including OpenSSH).

              Example:
               curl --upload-file local --append ftp://example.com/

       --aws-sigv4 <provider1[:provider2[:region[:service]]]>
              Use AWS V4 signature authentication in the transfer.

              The  provider argument is a string that is used by the algorithm
              when creating outgoing authentication headers.

              The region argument is a string that points to a geographic area
              of  a resources collection (region-code) when the region name is
              omitted from the endpoint.

              The service argument is a string that points to a function  pro-
              vided by a cloud (service-code) when the service name is omitted
              from the endpoint.

              Example:
               curl --aws-sigv4 "aws:amz:east-2:es" --user "key:secret" https://example.com

              Added in 7.75.0.

       --basic
              (HTTP) Tells curl to use  HTTP  Basic  authentication  with  the
              remote  host.  This  is  the  default and this option is usually
              pointless, unless you use it to override a previously set option
              that  sets  a  different  authentication method (such as --ntlm,
              --digest, or --negotiate).

              Used together with -u, --user.

              Example:
               curl -u name:password --basic https://example.com

              See also --proxy-basic.

       --cacert <file>
              (TLS) Tells curl to use the specified certificate file to verify
              the  peer.  The  file  may contain multiple CA certificates. The
              certificate(s) must be in PEM format. Normally curl is built  to
              use a default file for this, so this option is typically used to
              alter that default file.

              curl recognizes the environment variable named  'CURL_CA_BUNDLE'
              if  it  is  set,  and uses the given path as a path to a CA cert
              bundle. This option overrides that variable.

              The windows version of curl will automatically  look  for  a  CA
              certs file named 'curl-ca-bundle.crt', either in the same direc-
              tory as curl.exe, or in the Current Working Directory, or in any
              folder along your PATH.

              If  curl  is  built  against  the  NSS  SSL library, the NSS PEM
              PKCS#11 module (libnsspem.so) needs to  be  available  for  this
              option to work properly.

              (iOS  and macOS only) If curl is built against Secure Transport,
              then this option is supported for  backward  compatibility  with
              other  SSL  engines,  but it should not be set. If the option is
              not set, then curl will use the certificates in the  system  and
              user  Keychain to verify the peer, which is the preferred method
              of verifying the peer's certificate chain.

              (Schannel only) This option is supported for Schannel in Windows
              7  or later with libcurl 7.60 or later. This option is supported
              for backward compatibility with other SSL engines; instead it is
              recommended  to  use  Windows'  store  of root certificates (the
              default for Schannel).

              If this option is used several times, the last one will be used.

              Example:
               curl --cacert CA-file.txt https://example.com

       --capath <dir>
              (TLS)  Tells  curl to use the specified certificate directory to
              verify the peer. Multiple paths can be  provided  by  separating
              them with ":" (e.g.  "path1:path2:path3"). The certificates must
              be in PEM format, and if curl  is  built  against  OpenSSL,  the
              directory  must  have  been processed using the c_rehash utility
              supplied with OpenSSL. Using --capath can allow  OpenSSL-powered
              curl  to  make  SSL-connections much more efficiently than using
              --cacert if the --cacert file contains many CA certificates.

              If this option is set, the default capath value will be ignored,
              and if it is used several times, the last one will be used.

              Example:
               curl --capath /local/directory https://example.com

       --cert-status
              (TLS)  Tells curl to verify the status of the server certificate
              by using the Certificate Status Request (aka. OCSP stapling) TLS
              extension.

              If  this option is enabled and the server sends an invalid (e.g.
              expired) response, if the response suggests that the server cer-
              tificate  has  been  revoked, or no response at all is received,
              the verification fails.

              This is currently only implemented in the  OpenSSL,  GnuTLS  and
              NSS backends.

              Example:
               curl --cert-status https://example.com

              Added in 7.41.0.

       --cert-type <type>
              (TLS)  Tells  curl  what type the provided client certificate is
              using. PEM, DER, ENG and P12 are recognized types.  If not spec-
              ified, PEM is assumed.

              If this option is used several times, the last one will be used.

              Example:
               curl --cert-type PEM --cert file https://example.com

              See also -E, --cert, --key and --key-type.

       -E, --cert <certificate[:password]>
              (TLS) Tells curl to use the specified  client  certificate  file
              when getting a file with HTTPS, FTPS or another SSL-based proto-
              col. The certificate must be in PKCS#12 format if  using  Secure
              Transport,  or  PEM  format  if  using any other engine.  If the
              optional password is not specified, it will be  queried  for  on
              the terminal. Note that this option assumes a "certificate" file
              that is the private key and the client certificate concatenated!
              See -E, --cert and --key to specify them independently.

              If  curl  is  built against the NSS SSL library then this option
              can tell curl the nickname of the certificate to use within  the
              NSS  database defined by the environment variable SSL_DIR (or by
              default /etc/pki/nssdb). If the NSS  PEM  PKCS#11  module  (lib-
              nsspem.so)  is  available  then  PEM files may be loaded. If you
              want to use a file from the current directory, please precede it
              with  "./"  prefix, in order to avoid confusion with a nickname.
              If the nickname contains ":", it needs to be preceded by "\"  so
              that  it  is not recognized as password delimiter.  If the nick-
              name contains "\", it needs to be escaped as "\\" so that it  is
              not recognized as an escape character.

              If  curl is built against OpenSSL library, and the engine pkcs11
              is available, then a PKCS#11 URI (RFC 7512) can be used to spec-
              ify  a  certificate located in a PKCS#11 device. A string begin-
              ning with "pkcs11:" will be interpreted as a PKCS#11 URI.  If  a
              PKCS#11 URI is provided, then the --engine option will be set as
              "pkcs11" if none was provided and the --cert-type option will be
              set as "ENG" if none was provided.

              (iOS  and macOS only) If curl is built against Secure Transport,
              then the certificate string can either be the name of a certifi-
              cate/private  key in the system or user keychain, or the path to
              a PKCS#12-encoded certificate and private key. If  you  want  to
              use  a  file  from the current directory, please precede it with
              "./" prefix, in order to avoid confusion with a nickname.

              (Schannel only) Client certificates must be specified by a  path
              expression  to  a  certificate  store.  (Loading PFX is not sup-
              ported; you can import it to a store first). You can use "<store
              location>\<store  name>\<thumbprint>"  to refer to a certificate
              in  the  system  certificates  store,  for   example,   "Curren-
              tUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a".   Thumbprint
              is usually a SHA-1 hex string which you can see  in  certificate
              details.  Following  store locations are supported: CurrentUser,
              LocalMachine, CurrentService, Services,  CurrentUserGroupPolicy,
              LocalMachineGroupPolicy, LocalMachineEnterprise.

              If this option is used several times, the last one will be used.

              Example:
               curl --cert certfile --key keyfile https://example.com

              See also --cert-type, --key and --key-type.

       --ciphers <list of ciphers>
              (TLS) Specifies which ciphers to use in the connection. The list
              of  ciphers  must  specify  valid ciphers. Read up on SSL cipher
              list details on this URL:

               https://curl.se/docs/ssl-ciphers.html

              If this option is used several times, the last one will be used.

              Example:
               curl --ciphers ECDHE-ECDSA-AES256-CCM8 https://example.com

       --compressed-ssh
              (SCP SFTP) Enables built-in SSH compression.  This is a request,
              not an order; the server may or may not do it.

              Example:
               curl --compressed-ssh sftp://example.com/

              Added in 7.56.0.

       --compressed
              (HTTP) Request a compressed response using one of the algorithms
              curl supports, and automatically decompress the content. Headers
              are not modified.

              If this option is used  and  the  server  sends  an  unsupported
              encoding,  curl  will report an error. This is a request, not an
              order; the server may or may not deliver data compressed.

              Example:
               curl --compressed https://example.com

       -K, --config <file>
              Specify a text file to read curl  arguments  from.  The  command
              line  arguments  found  in the text file will be used as if they
              were provided on the command line.

              Options and their parameters must be specified on the same  line
              in the file, separated by whitespace, colon, or the equals sign.
              Long option names can optionally be given  in  the  config  file
              without the initial double dashes and if so, the colon or equals
              characters can be used as separators. If the option is specified
              with  one or two dashes, there can be no colon or equals charac-
              ter between the option and its parameter.

              If the parameter contains whitespace (or starts with  :  or  =),
              the  parameter  must  be  enclosed  within quotes. Within double
              quotes, the following escape sequences are  available:  \\,  \",
              \t,  \n,  \r  and  \v. A backslash preceding any other letter is
              ignored.

              If the first column of a config line is  a  '#'  character,  the
              rest of the line will be treated as a comment.

              Only write one option per physical line in the config file.

              Specify  the  filename  to -K, --config as '-' to make curl read
              the file from stdin.

              Note that to be able to specify a URL in the  config  file,  you
              need  to  specify  it  using the --url option, and not by simply
              writing the URL on its own line. So, it could  look  similar  to
              this:

              url = "https://curl.se/docs/"

              When  curl  is invoked, it (unless -q, --disable is used) checks
              for a default config file and uses it if found, even  when  this
              option  is  used.  The default config file is checked for in the
              following places in this order:

              1) Use the CURL_HOME environment variable if set

              2) Use the XDG_CONFIG_HOME environment variable if set (Added in
              7.73.0)

              3) Use the HOME environment variable if set

              4) Non-windows: use getpwuid to find the home directory

              5) Windows: use APPDATA if set

              6) Windows: use "USERPROFILE\Application Data" if set

              7)  On  windows, if there is no .curlrc file in the home dir, it
              checks for one in the same dir the curl executable is placed. On
              Unix-like  systems,  it will simply try to load .curlrc from the
              determined home dir.

              # --- Example file ---
              # this is a comment
              url = "example.com"
              output = "curlhere.html"
              user-agent = "superagent/1.0"

              # and fetch another URL too
              url = "example.com/docs/manpage.html"
              -O
              referer = "http://nowhereatall.example.com/"
              # --- End of example file ---

              This option can be used multiple times to load  multiple  config
              files.

              Example:
               curl --config file.txt https://example.com

       --connect-timeout <fractional seconds>
              Maximum  time  in  seconds  that  you allow curl's connection to
              take.  This only limits the connection phase, so  if  curl  con-
              nects  within the given period it will continue - if not it will
              exit.  Since version 7.32.0, this option accepts decimal values.

              If this option is used several times, the last one will be used.

              Examples:
               curl --connect-timeout 20 https://example.com
               curl --connect-timeout 3.14 https://example.com

              See also -m, --max-time.

       --connect-to <HOST1:PORT1:HOST2:PORT2>

              For  a  request  to  the  given  HOST1:PORT1  pair,  connect  to
              HOST2:PORT2 instead.  This option is suitable to direct requests
              at a specific server, e.g. at a specific cluster node in a clus-
              ter  of  servers. This option is only used to establish the net-
              work connection. It does NOT affect the  hostname/port  that  is
              used for TLS/SSL (e.g. SNI, certificate verification) or for the
              application protocols. "HOST1" and  "PORT1"  may  be  the  empty
              string, meaning "any host/port". "HOST2" and "PORT2" may also be
              the  empty  string,  meaning   "use   the   request's   original
              host/port".

              A "host" specified to this option is compared as a string, so it
              needs to match the name used in request URL. It  can  be  either
              numerical  such  as  "127.0.0.1"  or  the full host name such as
              "example.org".

              This option can be used many times to add many connect rules.

              Example:
               curl --connect-to example.com:443:example.net:8443 https://example.com

              See also --resolve and -H, --header. Added in 7.49.0.

       -C, --continue-at <offset>
              Continue/Resume a previous file transfer at  the  given  offset.
              The  given  offset  is  the  exact  number of bytes that will be
              skipped, counting from the beginning of the source  file  before
              it is transferred to the destination.  If used with uploads, the
              FTP server command SIZE will not be used by curl.

              Use "-C -" to tell curl to automatically find out  where/how  to
              resume  the  transfer. It then uses the given output/input files
              to figure that out.

              If this option is used several times, the last one will be used.

              Examples:
               curl -C - https://example.com
               curl -C 400 https://example.com

              See also -r, --range.

       -c, --cookie-jar <filename>
              (HTTP)  Specify to which file you want curl to write all cookies
              after a completed operation. Curl writes all  cookies  from  its
              in-memory  cookie storage to the given file at the end of opera-
              tions. If no cookies are known, no data  will  be  written.  The
              file  will  be written using the Netscape cookie file format. If
              you set the file name to a single dash, "-", the cookies will be
              written to stdout.

              This  command  line  option will activate the cookie engine that
              makes curl record and use cookies. Another way to activate it is
              to use the -b, --cookie option.

              If  the  cookie  jar  cannot be created or written to, the whole
              curl operation will not fail or even report  an  error  clearly.
              Using  -v,  --verbose  will get a warning displayed, but that is
              the only visible feedback you get  about  this  possibly  lethal
              situation.

              If  this  option  is used several times, the last specified file
              name will be used.

              Examples:
               curl -c store-here.txt https://example.com
               curl -c store-here.txt -b read-these https://example.com

       -b, --cookie <data|filename>
              (HTTP) Pass the data to the HTTP server in the Cookie header. It
              is  supposedly the data previously received from the server in a
              "Set-Cookie:"  line.   The  data  should  be   in   the   format
              "NAME1=VALUE1; NAME2=VALUE2".

              If  no '=' symbol is used in the argument, it is instead treated
              as a filename to read previously stored cookie from. This option
              also  activates  the  cookie  engine which will make curl record
              incoming cookies, which may be handy if you are  using  this  in
              combination  with  the  -L, --location option or do multiple URL
              transfers on the same invoke. If the  file  name  is  exactly  a
              minus ("-"), curl will instead read the contents from stdin.

              The file format of the file to read cookies from should be plain
              HTTP headers (Set-Cookie style) or the  Netscape/Mozilla  cookie
              file format.

              The  file  specified with -b, --cookie is only used as input. No
              cookies will be written to the file. To store cookies,  use  the
              -c, --cookie-jar option.

              If  you  use  the  Set-Cookie  file  format and do not specify a
              domain then the cookie is not sent since the domain  will  never
              match.  To  address this, set a domain in Set-Cookie line (doing
              that will include sub-domains) or preferably: use  the  Netscape
              format.

              This option can be used multiple times.

              Users  often  want  to  both  read cookies from a file and write
              updated cookies back to a file, so using both -b,  --cookie  and
              -c, --cookie-jar in the same command line is common.

              Examples:
               curl -b cookiefile https://example.com
               curl -b cookiefile -c cookiefile https://example.com

       --create-dirs
              When used in conjunction with the -o, --output option, curl will
              create the necessary local directory hierarchy as  needed.  This
              option  creates  the directories mentioned with the -o, --output
              option, nothing else. If the --output file name uses  no  direc-
              tory, or if the directories it mentions already exist, no direc-
              tories will be created.

              Created dirs are made with mode 0750 on unix style file systems.

              To  create remote directories when using FTP or SFTP, try --ftp-
              create-dirs.

              Example:
               curl --create-dirs --output local/dir/file https://example.com

       --create-file-mode <mode>
              (SFTP SCP FILE) When curl is used to create files remotely using
              one  of  the supported protocols, this option allows the user to
              set which 'mode' to set on the file at creation time, instead of
              the default 0644.

              This option takes an octal number as argument.

              If this option is used several times, the last one will be used.

              Example:
               curl --create-file-mode 0777 -T localfile sftp://example.com/new

              See also --ftp-create-dirs. Added in 7.75.0.

       --crlf (FTP SMTP)  Convert  LF  to  CRLF  in  upload.  Useful  for  MVS
              (OS/390).

              (SMTP added in 7.40.0)

              Example:
               curl --crlf -T file ftp://example.com/

       --crlfile <file>
              (TLS) Provide a file using PEM format with a Certificate Revoca-
              tion List that may specify peer certificates that are to be con-
              sidered revoked.

              If this option is used several times, the last one will be used.

              Example:
               curl --crlfile rejects.txt https://example.com

       --curves <algorithm list>
              (TLS) Tells curl to request specific curves to  use  during  SSL
              session  establishment  according  to  RFC  8422, 5.1.  Multiple
              algorithms can be provided by separating  them  with  ":"  (e.g.
              "X25519:P-521").   The parameter is available identically in the
              "openssl s_client/s_server" utilities.

              --curves allows a OpenSSL powered curl to  make  SSL-connections
              with  exactly  the  (EC) curve requested by the client, avoiding
              intransparent client/server negotiations.

              If this option is  set,  the  default  curves  list  built  into
              openssl will be ignored.

              Example:
               curl --curves X25519 https://example.com

              Added in 7.73.0.

       --data-ascii <data>
              (HTTP) This is just an alias for -d, --data.

              Example:
               curl --data-ascii @file https://example.com

       --data-binary <data>
              (HTTP)  This  posts data exactly as specified with no extra pro-
              cessing whatsoever.

              If you start the data with the letter @, the rest  should  be  a
              filename.   Data  is  posted  in  a similar manner as -d, --data
              does, except that newlines and carriage  returns  are  preserved
              and conversions are never done.

              Like  -d,  --data the default content-type sent to the server is
              application/x-www-form-urlencoded. If you want the  data  to  be
              treated as arbitrary binary data by the server then set the con-
              tent-type to octet-stream: -H "Content-Type:  application/octet-
              stream".

              If  this  option  is  used several times, the ones following the
              first will append data as described in -d, --data.

              Example:
               curl --data-binary @filename https://example.com

       --data-raw <data>
              (HTTP) This posts data similarly to -d, --data but  without  the
              special interpretation of the @ character.

              Examples:
               curl --data-raw "hello" https://example.com
               curl --data-raw "@at@at@" https://example.com

              See also -d, --data. Added in 7.43.0.

       --data-urlencode <data>
              (HTTP)  This posts data, similar to the other -d, --data options
              with the exception that this performs URL-encoding.

              To be CGI-compliant, the <data> part should begin  with  a  name
              followed  by a separator and a content specification. The <data>
              part can be passed to curl using one of the following syntaxes:

              content
                     This will make curl URL-encode the content and pass  that
                     on.  Just be careful so that the content does not contain
                     any = or @ symbols, as that will  then  make  the  syntax
                     match one of the other cases below!

              =content
                     This  will make curl URL-encode the content and pass that
                     on. The preceding = symbol is not included in the data.

              name=content
                     This will make curl URL-encode the content part and  pass
                     that  on.  Note that the name part is expected to be URL-
                     encoded already.

              @filename
                     This will  make  curl  load  data  from  the  given  file
                     (including  any  newlines), URL-encode that data and pass
                     it on in the POST.

              name@filename
                     This will  make  curl  load  data  from  the  given  file
                     (including  any  newlines), URL-encode that data and pass
                     it on in the POST. The  name  part  gets  an  equal  sign
                     appended, resulting in name=urlencoded-file-content. Note
                     that the name is expected to be URL-encoded already.

       Examples:
        curl --data-urlencode name=val https://example.com
        curl --data-urlencode =encodethis https://example.com
        curl --data-urlencode name@file https://example.com
        curl --data-urlencode @fileonly https://example.com

       See also -d, --data and --data-raw.

       -d, --data <data>
              (HTTP MQTT) Sends the specified data in a POST  request  to  the
              HTTP server, in the same way that a browser does when a user has
              filled in an HTML form and presses the submit button. This  will
              cause curl to pass the data to the server using the content-type
              application/x-www-form-urlencoded.  Compare to -F, --form.

              --data-raw is almost the same but does not have a special inter-
              pretation  of  the  @ character. To post data purely binary, you
              should instead use the --data-binary option.  To URL-encode  the
              value of a form field you may use --data-urlencode.

              If  any of these options is used more than once on the same com-
              mand line, the data pieces specified  will  be  merged  together
              with  a  separating  &-symbol.  Thus,  using  '-d name=daniel -d
              skill=lousy'  would  generate  a  post  chunk  that  looks  like
              'name=daniel&skill=lousy'.

              If  you  start  the data with the letter @, the rest should be a
              file name to read the data from, or - if you want curl  to  read
              the  data  from  stdin.  Posting data from a file named 'foobar'
              would thus be done with -d, --data @foobar. When -d,  --data  is
              told  to  read  from a file like that, carriage returns and new-
              lines will be stripped out. If you do not want the  @  character
              to have a special interpretation use --data-raw instead.

              Examples:
               curl -d "name=curl" https://example.com
               curl -d "name=curl" -d "tool=cmdline" https://example.com
               curl -d @filename https://example.com

              See  also  --data-binary,  --data-urlencode and --data-raw. This
              option overrides -F, --form and -I,  --head  and  -T,  --upload-
              file.

       --delegation <LEVEL>
              (GSS/kerberos)  Set  LEVEL to tell the server what it is allowed
              to delegate when it comes to user credentials.

              none   Do not allow any delegation.

              policy Delegates if and only if the OK-AS-DELEGATE flag  is  set
                     in  the  Kerberos  service  ticket,  which is a matter of
                     realm policy.

              always Unconditionally allow the server to delegate.

       If this option is used several times, the last one will be used.

       Example:
        curl --delegation "none" https://example.com

       --digest
              (HTTP) Enables HTTP Digest authentication. This is an  authenti-
              cation  scheme  that  prevents the password from being sent over
              the wire in clear text. Use this in combination with the  normal
              -u, --user option to set user name and password.

              If  this  option  is  used  several times, only the first one is
              used.

              Example:
               curl -u name:password --digest https://example.com

              See also -u, --user, --proxy-digest and --anyauth.  This  option
              overrides --basic and --ntlm and --negotiate.

       --disable-eprt
              (FTP) Tell curl to disable the use of the EPRT and LPRT commands
              when doing active FTP transfers. Curl will normally always first
              attempt  to use EPRT, then LPRT before using PORT, but with this
              option, it will use PORT right away. EPRT and  LPRT  are  exten-
              sions  to  the  original  FTP  protocol, and may not work on all
              servers, but they enable more functionality in a better way than
              the traditional PORT command.

              --eprt can be used to explicitly enable EPRT again and --no-eprt
              is an alias for --disable-eprt.

              If the server is accessed using IPv6, this option will  have  no
              effect as EPRT is necessary then.

              Disabling  EPRT only changes the active behavior. If you want to
              switch to passive mode you need to not  use  -P,  --ftp-port  or
              force it with --ftp-pasv.

              Example:
               curl --disable-eprt ftp://example.com/

       --disable-epsv
              (FTP)  Tell  curl  to  disable  the use of the EPSV command when
              doing passive FTP transfers. Curl  will  normally  always  first
              attempt  to  use EPSV before PASV, but with this option, it will
              not try using EPSV.

              --epsv can be used to explicitly enable EPSV again and --no-epsv
              is an alias for --disable-epsv.

              If  the  server is an IPv6 host, this option will have no effect
              as EPSV is necessary then.

              Disabling EPSV only changes the passive behavior. If you want to
              switch to active mode you need to use -P, --ftp-port.

              Example:
               curl --disable-epsv ftp://example.com/

       -q, --disable
              If  used  as the first parameter on the command line, the curlrc
              config file will not be read and used. See the -K, --config  for
              details on the default config file search path.

              Example:
               curl -q https://example.com

       --disallow-username-in-url
              (HTTP)  This  tells  curl  to  exit if passed a url containing a
              username. This is probably most useful when  the  URL  is  being
              provided at run-time or similar.

              Example:
               curl --disallow-username-in-url https://example.com

              See also --proto. Added in 7.61.0.

       --dns-interface <interface>
              (DNS)  Tell  curl  to send outgoing DNS requests through <inter-
              face>. This option is a counterpart to --interface  (which  does
              not  affect  DNS). The supplied string must be an interface name
              (not an address).

              Example:
               curl --dns-interface eth0 https://example.com

              See also --dns-ipv4-addr  and  --dns-ipv6-addr.  --dns-interface
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-ipv4-addr <address>
              (DNS) Tell curl to bind to <ip-address>  when  making  IPv4  DNS
              requests,  so that the DNS requests originate from this address.
              The argument should be a single IPv4 address.

              If this option is used several times, the last one will be used.

              Example:
               curl --dns-ipv4-addr 10.1.2.3 https://example.com

              See  also  --dns-interface  and --dns-ipv6-addr. --dns-ipv4-addr
              requires that the underlying libcurl was  built  to  support  c-
              ares. Added in 7.33.0.

       --dns-ipv6-addr <address>
              (DNS)  Tell  curl  to  bind to <ip-address> when making IPv6 DNS
              requests, so that the DNS requests originate from this  address.
              The argument should be a single IPv6 address.

              If this option is used several times, the last one will be used.

              Example:
               curl --dns-ipv6-addr 2a04:4e42::561 https://example.com

              See also --dns-interface  and  --dns-ipv4-addr.  --dns-ipv6-addr
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-servers <addresses>
              Set the list of DNS servers to be used  instead  of  the  system
              default.  The list of IP addresses should be separated with com-
              mas. Port numbers may also optionally be given as :<port-number>
              after each IP address.

              If this option is used several times, the last one will be used.

              Example:
               curl --dns-servers 192.168.0.1,192.168.0.2 https://example.com

              --dns-servers requires that the underlying libcurl was built  to
              support c-ares. Added in 7.33.0.

       --doh-cert-status
              (all) Same as --cert-status but used for DoH (DNS-over-HTTPS).

              Example:
               curl --doh-cert-status --doh-url https://doh.example https://example.com

              Added in 7.76.0.

       --doh-insecure
              (all)  Same as -k, --insecure but used for DoH (DNS-over-HTTPS).

              Example:
               curl --doh-insecure --doh-url https://doh.example https://example.com

              Added in 7.76.0.

       --doh-url <URL>
              (all) Specifies which DNS-over-HTTPS  (DoH)  server  to  use  to
              resolve  hostnames,  instead  of using the default name resolver
              mechanism. The URL must be HTTPS.

              Some SSL options that you set for your transfer  will  apply  to
              DoH  since  the  name  lookups take place over SSL. However, the
              certificate verification settings are not inherited and  can  be
              controlled  separately via --doh-insecure and --doh-cert-status.

              If this option is used several times, the last one will be used.

              Example:
               curl --doh-url https://doh.example https://example.com

              Added in 7.62.0.

       -D, --dump-header <filename>
              (HTTP  FTP) Write the received protocol headers to the specified
              file. If no headers are received, the use of  this  option  will
              create an empty file.

              When  used  in FTP, the FTP server response lines are considered
              being "headers" and thus are saved there.

              If this option is used several times, the last one will be used.

              Example:
               curl --dump-header store.txt https://example.com

              See also -o, --output.

       --egd-file <file>
              (TLS)  Specify  the  path  name  to the Entropy Gathering Daemon
              socket. The socket is used to seed the  random  engine  for  SSL
              connections.

              Example:
               curl --egd-file /random/here https://example.com

              See also --random-file.

       --engine <name>
              (TLS)  Select the OpenSSL crypto engine to use for cipher opera-
              tions. Use --engine list to print a list of build-time supported
              engines.  Note  that  not all (and possibly none) of the engines
              may be available at run-time.

              Example:
               curl --engine flavor https://example.com

       --etag-compare <file>
              (HTTP) This option makes a conditional HTTP request for the spe-
              cific ETag read from the given file by sending a custom If-None-
              Match header using the stored ETag.

              For correct results, make sure that the specified file  contains
              only  a  single  line  with  the  desired ETag. An empty file is
              parsed as an empty ETag.

              Use the option  --etag-save  to  first  save  the  ETag  from  a
              response,  and then use this option to compare against the saved
              ETag in a subsequent request.

              Example:
               curl --etag-compare etag.txt https://example.com

              Added in 7.68.0.

       --etag-save <file>
              (HTTP) This option saves an HTTP ETag to the specified file.  An
              ETag  is  a  caching  related  header,  usually  returned  in  a
              response.

              If no ETag is sent by the server, an empty file is created.

              Example:
               curl --etag-save storetag.txt https://example.com

              Added in 7.68.0.

       --expect100-timeout <seconds>
              (HTTP) Maximum time in seconds that you allow curl to wait for a
              100-continue  response  when curl emits an Expects: 100-continue
              header in its request. By default curl  will  wait  one  second.
              This  option accepts decimal values! When curl stops waiting, it
              will continue as if the response has been received.

              Example:
               curl --expect100-timeout 2.5 -T file https://example.com

              See also --connect-timeout. Added in 7.47.0.

       --fail-early
              Fail and exit on the first detected transfer error.

              When curl is used to do multiple transfers on the command  line,
              it  will  attempt  to  operate on each given URL, one by one. By
              default, it will ignore errors if there are more URLs given  and
              the  last  URL's  success  will  determine  the  error code curl
              returns. So early failures will be "hidden" by  subsequent  suc-
              cessful transfers.

              Using  this  option,  curl  will  instead return an error on the
              first transfer that fails, independent of  the  amount  of  URLs
              that  are given on the command line. This way, no transfer fail-
              ures go undetected by scripts and similar.

              This option is global and does not need to be specified for each
              use of -:, --next.

              This option does not imply -f, --fail, which causes transfers to
              fail due to the server's HTTP status code. You can  combine  the
              two options, however note -f, --fail is not global and is there-
              fore contained by -:, --next.

              Example:
               curl --fail-early https://example.com https://two.example

              Added in 7.52.0.

       --fail-with-body
              (HTTP) Return an error on server errors where the HTTP  response
              code  is  400  or  greater). In normal cases when an HTTP server
              fails to deliver a document, it returns an HTML document stating
              so  (which  often  also  describes why and more). This flag will
              still allow curl to output and save that  content  but  also  to
              return error 22.

              This  is  an  alternative  option to -f, --fail which makes curl
              fail for the same circumstances but without saving the  content.

              Example:
               curl --fail-with-body https://example.com

              See also -f, --fail. Added in 7.76.0.

       -f, --fail
              (HTTP)  Fail  silently (no output at all) on server errors. This
              is mostly done to enable scripts etc to better deal with  failed
              attempts. In normal cases when an HTTP server fails to deliver a
              document, it returns an HTML document stating  so  (which  often
              also  describes  why and more). This flag will prevent curl from
              outputting that and return error 22.

              This method is not fail-safe and there are occasions where  non-
              successful  response  codes  will  slip through, especially when
              authentication is involved (response codes 401 and 407).

              Example:
               curl --fail https://example.com

              See also --fail-with-body.

       --false-start
              (TLS) Tells curl to use false start during  the  TLS  handshake.
              False  start  is  a  mode  where a TLS client will start sending
              application data before verifying the server's Finished message,
              thus saving a round trip when performing a full handshake.

              This  is currently only implemented in the NSS and Secure Trans-
              port (on iOS 7.0 or later, or OS X 10.9 or later) backends.

              Example:
               curl --false-start https://example.com

              Added in 7.42.0.

       --form-string <name=string>
              (HTTP SMTP IMAP) Similar to -F, --form  except  that  the  value
              string  for  the  named parameter is used literally. Leading '@'
              and '<' characters, and the ';type=' string in the value have no
              special meaning. Use this in preference to -F, --form if there's
              any possibility that the string value may  accidentally  trigger
              the '@' or '<' features of -F, --form.

              Example:
               curl --form-string "data" https://example.com

              See also -F, --form.

       -F, --form <name=content>
              (HTTP  SMTP  IMAP) For HTTP protocol family, this lets curl emu-
              late a filled-in form in which a user  has  pressed  the  submit
              button.  This  causes  curl  to POST data using the Content-Type
              multipart/form-data according to RFC 2388.

              For SMTP and IMAP protocols, this is the means to compose a mul-
              tipart mail message to transmit.

              This  enables  uploading of binary files etc. To force the 'con-
              tent' part to be a file, prefix the file name with an @ sign. To
              just get the content part from a file, prefix the file name with
              the symbol <. The difference between @ and  <  is  then  that  @
              makes  a  file  get attached in the post as a file upload, while
              the < makes a text field and just get the contents for that text
              field from a file.

              Tell  curl to read content from stdin instead of a file by using
              - as filename. This goes for both @ and < constructs. When stdin
              is  used,  the  contents  is buffered in memory first by curl to
              determine its size and allow  a  possible  resend.   Defining  a
              part's  data from a named non-regular file (such as a named pipe
              or similar) is unfortunately not subject to buffering  and  will
              be effectively read at transmission time; since the full size is
              unknown before the transfer starts, such data is sent as  chunks
              by HTTP and rejected by IMAP.

              Example: send an image to an HTTP server, where 'profile' is the
              name of the form-field to which the file  portrait.jpg  will  be
              the input:

               curl -F profile=@portrait.jpg https://example.com/upload.cgi

              Example:  send your name and shoe size in two text fields to the
              server:

               curl -F name=John -F shoesize=11 https://example.com/

              Example: send your essay in a text field to the server. Send  it
              as  a plain text field, but get the contents for it from a local
              file:

               curl -F "story=<hugefile.txt" https://example.com/

              You can also  tell  curl  what  Content-Type  to  use  by  using
              'type=', in a manner similar to:

               curl -F "web=@index.html;type=text/html" example.com

              or

               curl -F "name=daniel;type=text/foo" example.com

              You  can  also explicitly change the name field of a file upload
              part by setting filename=, like this:

               curl -F "file=@localfile;filename=nameinpost" example.com

              If filename/path contains ',' or ';', it must be quoted by  dou-
              ble-quotes like:

               curl  -F "file=@\"local,file\";filename=\"name;in;post\"" exam-
              ple.com

              or

               curl  -F   'file=@"local,file";filename="name;in;post"'   exam-
              ple.com

              Note  that  if  a  filename/path is quoted by double-quotes, any
              double-quote or backslash within the filename must be escaped by
              backslash.

              Quoting  must  also  be  applied to non-file data if it contains
              semicolons, leading/trailing spaces or leading double quotes:

               curl -F  'colors="red;  green;  blue";type=text/x-myapp'  exam-
              ple.com

              You  can  add  custom  headers to the field by setting headers=,
              like

                curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com

              or

                curl -F "submit=OK;headers=@headerfile" example.com

              The headers= keyword may appear more that once and  above  notes
              about  quoting  apply.  When headers are read from a file, Empty
              lines and lines starting with '#' are comments and ignored; each
              header can be folded by splitting between two words and starting
              the continuation line with a  space;  embedded  carriage-returns
              and  trailing  spaces  are  stripped.   Here  is an example of a
              header file contents:

                # This file contain two headers.
                X-header-1: this is a header

                # The following header is folded.
                X-header-2: this is
                 another header


              To support  sending  multipart  mail  messages,  the  syntax  is
              extended as follows:
              -  name can be omitted: the equal sign is the first character of
              the argument,
              - if data starts with '(', this signals to start  a  new  multi-
              part: it can be followed by a content type specification.
              - a multipart can be terminated with a '=)' argument.

              Example:  the  following  command sends an SMTP mime e-mail con-
              sisting in an inline part in two alternative formats: plain text
              and HTML. It attaches a text file:

               curl -F '=(;type=multipart/alternative' \
                       -F '=plain text message' \
                       -F '= <body>HTML message</body>;type=text/html' \
                    -F '=)' -F '=@textfile.txt' ...  smtp://example.com

              Data  can  be  encoded  for  transfer  using encoder=. Available
              encodings are binary and 8bit that do nothing else  than  adding
              the  corresponding  Content-Transfer-Encoding  header, 7bit that
              only rejects 8-bit characters with  a  transfer  error,  quoted-
              printable  and  base64 that encodes data according to the corre-
              sponding schemes, limiting lines length to 76 characters.

              Example: send multipart mail with a quoted-printable  text  mes-
              sage and a base64 attached file:

               curl -F '=text message;encoder=quoted-printable' \
                    -F '=@localfile;encoder=base64' ... smtp://example.com

              See further examples and details in the MANUAL.

              This option can be used multiple times.

              Example:
               curl --form "name=curl" --form "file=@loadthis" https://example.com

              This  option  overrides  -d,  --data  and  -I,  --head  and  -T,
              --upload-file.

       --ftp-account <data>
              (FTP) When an FTP server asks for "account data" after user name
              and  password has been provided, this data is sent off using the
              ACCT command.

              If this option is used several times, the last one will be used.

              Example:
               curl --ftp-account "mr.robot" ftp://example.com/

       --ftp-alternative-to-user <command>
              (FTP)  If  authenticating with the USER and PASS commands fails,
              send this  command.   When  connecting  to  Tumbleweed's  Secure
              Transport  server  over  FTPS  using a client certificate, using
              "SITE AUTH" will tell the server to retrieve the  username  from
              the certificate.

              Example:
               curl --ftp-alternative-to-user "U53r" ftp://example.com

       --ftp-create-dirs
              (FTP  SFTP)  When  an FTP or SFTP URL/operation uses a path that
              does not currently exist on the server, the standard behavior of
              curl is to fail. Using this option, curl will instead attempt to
              create missing directories.

              Example:
               curl --ftp-create-dirs -T file ftp://example.com/remote/path/file

              See also --create-dirs.

       --ftp-method <method>
              (FTP) Control what method curl should use to reach a file on  an
              FTP(S)  server. The method argument should be one of the follow-
              ing alternatives:

              multicwd
                     curl does a single CWD operation for each  path  part  in
                     the  given URL. For deep hierarchies this means many com-
                     mands. This is how RFC 1738 says it should be done.  This
                     is the default but the slowest behavior.

              nocwd  curl  does  no  CWD at all. curl will do SIZE, RETR, STOR
                     etc and give a full path to the server for all these com-
                     mands. This is the fastest behavior.

              singlecwd
                     curl does one CWD with the full target directory and then
                     operates on the file "normally"  (like  in  the  multicwd
                     case).  This  is  somewhat  more standards compliant than
                     'nocwd' but without the full penalty of 'multicwd'.

       Examples:
        curl --ftp-method multicwd ftp://example.com/dir1/dir2/file
        curl --ftp-method nocwd ftp://example.com/dir1/dir2/file
        curl --ftp-method singlecwd ftp://example.com/dir1/dir2/file

       --ftp-pasv
              (FTP) Use passive mode for the data connection. Passive  is  the
              internal  default behavior, but using this option can be used to
              override a previous -P, --ftp-port option.

              If this option is used several times,  only  the  first  one  is
              used.  Undoing  an enforced passive really is not doable but you
              must then instead enforce the correct -P, --ftp-port again.

              Passive mode means that curl will try the EPSV command first and
              then PASV, unless --disable-epsv is used.

              Example:
               curl --ftp-pasv ftp://example.com/

              See also --disable-epsv.

       -P, --ftp-port <address>
              (FTP)  Reverses  the  default initiator/listener roles when con-
              necting with FTP. This option makes curl use active  mode.  curl
              then  tells the server to connect back to the client's specified
              address and port, while passive mode asks the server to setup an
              IP  address  and  port for it to connect to. <address> should be
              one of:

              interface
                     e.g. "eth0" to specify which interface's IP  address  you
                     want to use (Unix only)

              IP address
                     e.g. "192.168.10.1" to specify the exact IP address

              host name
                     e.g. "my.host.domain" to specify the machine

              -      make  curl  pick the same IP address that is already used
                     for the control connection

       If this option is used several times, the last one will be  used.  Dis-
       able  the  use  of PORT with --ftp-pasv. Disable the attempt to use the
       EPRT command instead of PORT by using --disable-eprt.  EPRT  is  really
       PORT++.

       You  can  also  append ":[start]-[end]" to the right of the address, to
       tell curl what TCP port range to use. That means  you  specify  a  port
       range,  from a lower to a higher number. A single number works as well,
       but do note that it increases the risk of failure since  the  port  may
       not be available.


       Examples:
        curl -P - ftp:/example.com
        curl -P eth0 ftp:/example.com
        curl -P 192.168.0.2 ftp:/example.com

       See also --ftp-pasv and --disable-eprt.

       --ftp-pret
              (FTP)  Tell  curl to send a PRET command before PASV (and EPSV).
              Certain FTP servers, mainly drftpd,  require  this  non-standard
              command  for  directory  listings as well as up and downloads in
              PASV mode.

              Example:
               curl --ftp-pret ftp://example.com/

       --ftp-skip-pasv-ip
              (FTP) Tell curl to not use the IP address the server suggests in
              its  response to curl's PASV command when curl connects the data
              connection. Instead curl will re-use  the  same  IP  address  it
              already uses for the control connection.

              Since curl 7.74.0 this option is enabled by default.

              This  option has no effect if PORT, EPRT or EPSV is used instead
              of PASV.

              Example:
               curl --ftp-skip-pasv-ip ftp://example.com/

              See also --ftp-pasv.

       --ftp-ssl-ccc-mode <active/passive>
              (FTP) Sets the CCC mode. The passive mode will not initiate  the
              shutdown, but instead wait for the server to do it, and will not
              reply to the shutdown from the server. The active mode initiates
              the shutdown and waits for a reply from the server.

              Example:
               curl --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/

              See also --ftp-ssl-ccc.

       --ftp-ssl-ccc
              (FTP)  Use  CCC  (Clear  Command Channel) Shuts down the SSL/TLS
              layer after authenticating. The rest of the control channel com-
              munication  will be unencrypted. This allows NAT routers to fol-
              low the FTP transaction. The default mode is passive.

              Example:
               curl --ftp-ssl-ccc ftps://example.com/

              See also --ssl and --ftp-ssl-ccc-mode.

       --ftp-ssl-control
              (FTP) Require SSL/TLS for the FTP  login,  clear  for  transfer.
              Allows  secure  authentication, but non-encrypted data transfers
              for efficiency.  Fails the transfer if the server does not  sup-
              port SSL/TLS.

              Example:
               curl --ftp-ssl-control ftp://example.com

       -G, --get
              When  used,  this  option  will make all data specified with -d,
              --data, --data-binary or --data-urlencode to be used in an  HTTP
              GET  request instead of the POST request that otherwise would be
              used. The data will be appended to the URL with a '?' separator.

              If  used  in  combination  with  -I,  --head, the POST data will
              instead be appended to the URL with a HEAD request.

              If this option is used several times,  only  the  first  one  is
              used. This is because undoing a GET does not make sense, but you
              should then instead enforce the alternative method you prefer.

              Examples:
               curl --get https://example.com
               curl --get -d "tool=curl" -d "age=old" https://example.com
               curl --get -I -d "tool=curl" https://example.com

       -g, --globoff
              This option switches off the "URL globbing parser". When you set
              this  option, you can specify URLs that contain the letters {}[]
              without having curl itself interpret them. Note that these  let-
              ters  are  not  normal  legal  URL  contents  but they should be
              encoded according to the URI standard.

              Example:
               curl -g "https://example.com/{[]}}}}"

       --happy-eyeballs-timeout-ms <milliseconds>
              Happy Eyeballs is an algorithm that attempts to connect to  both
              IPv4  and  IPv6  addresses  for  dual-stack hosts, giving IPv6 a
              head-start of the specified number of milliseconds. If the  IPv6
              address  cannot be connected to within that time, then a connec-
              tion attempt is made to the IPv4 address in parallel. The  first
              connection to be established is the one that is used.

              The  range of suggested useful values is limited. Happy Eyeballs
              RFC 6555 says "It is RECOMMENDED  that  connection  attempts  be
              paced  150-250 ms apart to balance human factors against network
              load." libcurl currently defaults to 200 ms. Firefox and  Chrome
              currently default to 300 ms.

              If this option is used several times, the last one will be used.

              Example:
               curl --happy-eyeballs-timeout-ms 500 https://example.com

              Added in 7.59.0.

       --haproxy-protocol
              (HTTP) Send a HAProxy PROXY protocol v1 header at the  beginning
              of  the  connection.  This  is  used  by some load balancers and
              reverse proxies to indicate the client's  true  IP  address  and
              port.

              This  option is primarily useful when sending test requests to a
              service that expects this header.

              Example:
               curl --haproxy-protocol https://example.com

              Added in 7.60.0.

       -I, --head
              (HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the
              command  HEAD which this uses to get nothing but the header of a
              document. When used on an FTP or FILE file,  curl  displays  the
              file size and last modification time only.

              Example:
               curl -I https://example.com

       -H, --header <header/@file>
              (HTTP)  Extra header to include in the request when sending HTTP
              to a server. You may specify any number of extra  headers.  Note
              that if you should add a custom header that has the same name as
              one of the internal ones curl would  use,  your  externally  set
              header will be used instead of the internal one. This allows you
              to make even trickier stuff than curl  would  normally  do.  You
              should  not  replace internally set headers without knowing per-
              fectly well what you are doing. Remove  an  internal  header  by
              giving  a  replacement  without content on the right side of the
              colon, as in: -H "Host:". If you send the custom header with no-
              value  then its header must be terminated with a semicolon, such
              as -H "X-Custom-Header;" to send "X-Custom-Header:".

              curl will make sure that each header  you  add/replace  is  sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              This  option can take an argument in @filename style, which then
              adds a header for each line in the input  file.  Using  @-  will
              make curl read the header file from stdin. Added in 7.55.0.

              You  need  --proxy-header  to send custom headers intended for a
              HTTP proxy. Added in 7.37.0.

              Passing on a "Transfer-Encoding: chunked" header  when  doing  a
              HTTP  request  with a request body, will make curl send the data
              using chunked encoding.

              WARNING: headers set  with  this  option  will  be  set  in  all
              requests  -  even  after  redirects are followed, like when told
              with -L, --location. This can lead to the header being  sent  to
              other  hosts than the original host, so sensitive headers should
              be used with caution combined with following redirects.

              This option can be used  multiple  times  to  add/replace/remove
              multiple headers.

              Examples:
               curl -H "X-First-Name: Joe" https://example.com
               curl -H "User-Agent: yes-please/2000" https://example.com
               curl -H "Host:" https://example.com

              See also -A, --user-agent and -e, --referer.

       -h, --help <category>
              Usage  help.  This  lists all commands of the <category>.  If no
              arg was provided, curl will display the most  important  command
              line  arguments.   If the argument "all" was provided, curl will
              display all options available.  If the argument  "category"  was
              provided, curl will display all categories and their meanings.

              Example:
               curl --help all

       --hostpubmd5 <md5>
              (SFTP  SCP)  Pass a string containing 32 hexadecimal digits. The
              string should be the 128 bit MD5 checksum of the  remote  host's
              public key, curl will refuse the connection with the host unless
              the md5sums match.

              Example:
               curl --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/

       --hostpubsha256 <sha256>
              (SFTP SCP) Pass a string containing a Base64-encoded SHA256 hash
              of the remote host's public key. Curl will refuse the connection
              with the host unless the hashes match.

              Example:
               curl --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/

              Added in 7.80.0.

       --hsts <file name>
              (HTTPS) This option enables HSTS for the transfer. If  the  file
              name  points  to an existing HSTS cache file, that will be used.
              After a completed transfer, the cache will be saved to the  file
              name again if it has been modified.

              Specify a "" file name (zero length) to avoid loading/saving and
              make curl just handle HSTS in memory.

              If this option is used several times, curl  will  load  contents
              from all the files but the last one will be used for saving.

              Example:
               curl --hsts cache.txt https://example.com

              Added in 7.74.0.

       --http0.9
              (HTTP) Tells curl to be fine with HTTP version 0.9 response.

              HTTP/0.9  is  a completely headerless response and therefore you
              can also connect with this to non-HTTP servers and still  get  a
              response  since  curl  will  simply transparently downgrade - if
              allowed.

              Since curl 7.66.0, HTTP/0.9 is disabled by default.

              Example:
               curl --http0.9 https://example.com

              Added in 7.64.0.

       -0, --http1.0
              (HTTP) Tells curl to use HTTP version 1.0 instead of  using  its
              internally preferred HTTP version.

              Example:
               curl --http1.0 https://example.com

              This option overrides --http1.1 and --http2.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1.

              Example:
               curl --http1.1 https://example.com

              This  option  overrides  -0,  --http1.0  and  --http2.  Added in
              7.33.0.

       --http2-prior-knowledge
              (HTTP) Tells curl to  issue  its  non-TLS  HTTP  requests  using
              HTTP/2  without  HTTP/1.1  Upgrade.  It requires prior knowledge
              that the server supports HTTP/2 straight  away.  HTTPS  requests
              will  still  do HTTP/2 the standard way with negotiated protocol
              version in the TLS handshake.

              Example:
               curl --http2-prior-knowledge https://example.com

              --http2-prior-knowledge requires that the underlying libcurl was
              built to support HTTP/2. This option overrides --http1.1 and -0,
              --http1.0 and --http2. Added in 7.49.0.

       --http2
              (HTTP) Tells curl to use HTTP version 2.

              For HTTPS, this means curl will attempt to negotiate  HTTP/2  in
              the TLS handshake. curl does this by default.

              For HTTP, this means curl will attempt to upgrade the request to
              HTTP/2 using the Upgrade: request header.

              Example:
               curl --http2 https://example.com

              See also --http1.1 and --http3. --http2 requires that the under-
              lying libcurl was built to support HTTP/2. This option overrides
              --http1.1 and -0, --http1.0 and  --http2-prior-knowledge.  Added
              in 7.33.0.

       --http3
              (HTTP)  WARNING: this option is experimental. Do not use in pro-
              duction.

              Tells curl to use HTTP version 3 directly to the host  and  port
              number used in the URL. A normal HTTP/3 transaction will be done
              to a host and then get redirected via Alt-Svc, but  this  option
              allows  a  user to circumvent that when you know that the target
              speaks HTTP/3 on the given host and port.

              This option will make curl fail if a QUIC connection  cannot  be
              established,  it cannot fall back to a lower HTTP version on its
              own.

              Example:
               curl --http3 https://example.com

              See also --http1.1 and --http2. --http3 requires that the under-
              lying libcurl was built to support HTTP/3. This option overrides
              --http1.1 and -0, --http1.0 and --http2 and --http2-prior-knowl-
              edge. Added in 7.66.0.

       --ignore-content-length
              (FTP  HTTP)  For HTTP, Ignore the Content-Length header. This is
              particularly useful for servers running Apache 1.x,  which  will
              report  incorrect  Content-Length  for files larger than 2 giga-
              bytes.

              For FTP (since 7.46.0), skip the RETR command to figure out  the
              size before downloading a file.

              This  option  does not work for HTTP if libcurl was built to use
              hyper.

              Example:
               curl --ignore-content-length https://example.com

       -i, --include
              Include the HTTP  response  headers  in  the  output.  The  HTTP
              response  headers  can include things like server name, cookies,
              date of the document, HTTP version and more...

              To view the request headers, consider the -v, --verbose  option.

              Example:
               curl -i https://example.com

              See also -v, --verbose.

       -k, --insecure
              (TLS) By default, every SSL connection curl makes is verified to
              be secure. This option allows curl to proceed and  operate  even
              for server connections otherwise considered insecure.

              The  server  connection  is verified by making sure the server's
              certificate contains the right name  and  verifies  successfully
              using the cert store.

              See this online resource for further details:
               https://curl.se/docs/sslcerts.html

              WARNING: this makes the transfer insecure.

              Example:
               curl --insecure https://example.com

              See also --proxy-insecure and --cacert.

       --interface <name>
              Perform  an operation using a specified interface. You can enter
              interface name, IP address or host name. An example  could  look
              like:

               curl --interface eth0:1 https://www.example.com/

              If this option is used several times, the last one will be used.

              On Linux it can be used to specify a VRF, but the  binary  needs
              to  either  have CAP_NET_RAW or to be run as root. More informa-
              tion  about  Linux  VRF:   https://www.kernel.org/doc/Documenta-
              tion/networking/vrf.txt

              Example:
               curl --interface eth0 https://example.com

              See also --dns-interface.

       -4, --ipv4
              This  option tells curl to resolve names to IPv4 addresses only,
              and not for example try IPv6.

              Example:
               curl --ipv4 https://example.com

              See also  --http1.1  and  --http2.  This  option  overrides  -6,
              --ipv6.

       -6, --ipv6
              This  option tells curl to resolve names to IPv6 addresses only,
              and not for example try IPv4.

              Example:
               curl --ipv6 https://example.com

              See also  --http1.1  and  --http2.  This  option  overrides  -4,
              --ipv4.

       -j, --junk-session-cookies
              (HTTP) When curl is told to read cookies from a given file, this
              option will make it discard all  "session  cookies".  This  will
              basically  have  the same effect as if a new session is started.
              Typical browsers always discard session cookies  when  they  are
              closed down.

              Example:
               curl --junk-session-cookies -b cookies.txt https://example.com

              See also -b, --cookie and -c, --cookie-jar.

       --keepalive-time <seconds>
              This  option  sets  the  time  a connection needs to remain idle
              before sending keepalive probes and the time between  individual
              keepalive probes. It is currently effective on operating systems
              offering  the  TCP_KEEPIDLE  and  TCP_KEEPINTVL  socket  options
              (meaning  Linux, recent AIX, HP-UX and more). This option has no
              effect if --no-keepalive is used.

              If this option is used several times, the last one will be used.
              If unspecified, the option defaults to 60 seconds.

              Example:
               curl --keepalive-time 20 https://example.com

       --key-type <type>
              (TLS)  Private key file type. Specify which type your --key pro-
              vided private key is. DER, PEM, and ENG are  supported.  If  not
              specified, PEM is assumed.

              If this option is used several times, the last one will be used.

              Example:
               curl --key-type DER --key here https://example.com

       --key <key>
              (TLS SSH) Private key file name. Allows you to provide your pri-
              vate  key in this separate file. For SSH, if not specified, curl
              tries  the  following  candidates  in  order:   '~/.ssh/id_rsa',
              '~/.ssh/id_dsa', './id_rsa', './id_dsa'.

              If  curl is built against OpenSSL library, and the engine pkcs11
              is available, then a PKCS#11 URI (RFC 7512) can be used to spec-
              ify  a  private key located in a PKCS#11 device. A string begin-
              ning with "pkcs11:" will be interpreted as a PKCS#11 URI.  If  a
              PKCS#11 URI is provided, then the --engine option will be set as
              "pkcs11" if none was provided and the --key-type option will  be
              set as "ENG" if none was provided.

              If this option is used several times, the last one will be used.

              Example:
               curl --cert certificate --key here https://example.com

       --krb <level>
              (FTP) Enable Kerberos authentication and use. The level must  be
              entered and should be one of 'clear', 'safe', 'confidential', or
              'private'. Should you use a level that  is  not  one  of  these,
              'private' will instead be used.

              If this option is used several times, the last one will be used.

              Example:
               curl --krb clear ftp://example.com/

              --krb requires that the underlying libcurl was built to  support
              Kerberos.

       --libcurl <file>
              Append  this  option  to any ordinary curl command line, and you
              will get libcurl-using C source code written to  the  file  that
              does the equivalent of what your command-line operation does!

              This option is global and does not need to be specified for each
              use of -:, --next.

              If this option is used several times, the last given  file  name
              will be used.

              Example:
               curl --libcurl client.c https://example.com

       --limit-rate <speed>
              Specify  the  maximum  transfer  rate you want curl to use - for
              both downloads and uploads. This feature is useful if you have a
              limited  pipe  and  you would like your transfer not to use your
              entire bandwidth. To make it slower than it otherwise would  be.

              The  given speed is measured in bytes/second, unless a suffix is
              appended.  Appending 'k' or 'K' will count the number  as  kilo-
              bytes,  'm' or 'M' makes it megabytes, while 'g' or 'G' makes it
              gigabytes. The suffixes (k, M, G, T,  P)  are  1024  based.  For
              example 1k is 1024. Examples: 200K, 3m and 1G.

              The rate limiting logic works on averaging the transfer speed to
              no more than the set threshold over a period  of  multiple  sec-
              onds.

              If  you  also use the -Y, --speed-limit option, that option will
              take precedence and might cripple the rate-limiting slightly, to
              help keeping the speed-limit logic working.

              If this option is used several times, the last one will be used.

              Examples:
               curl --limit-rate 100K https://example.com
               curl --limit-rate 1000 https://example.com
               curl --limit-rate 10M https://example.com

       -l, --list-only
              (FTP POP3) (FTP) When listing  an  FTP  directory,  this  switch
              forces  a  name-only view. This is especially useful if the user
              wants to machine-parse the contents of an  FTP  directory  since
              the  normal  directory view does not use a standard look or for-
              mat. When used like this, the option causes an NLST  command  to
              be sent to the server instead of LIST.

              Note:  Some  FTP  servers  list  only files in their response to
              NLST; they do not include sub-directories and symbolic links.

              (POP3) When retrieving a specific email from POP3,  this  switch
              forces  a  LIST command to be performed instead of RETR. This is
              particularly useful if the user wants to see if a specific  mes-
              sage-id exists on the server and what size it is.

              Note:  When combined with -X, --request, this option can be used
              to send a UIDL command instead, so the user may use the  email's
              unique  identifier  rather  than  its  message-id  to  make  the
              request.

              Example:
               curl --list-only ftp://example.com/dir/

       --local-port <num/range>
              Set a preferred single number or range (FROM-TO) of  local  port
              numbers to use for the connection(s).  Note that port numbers by
              nature are a scarce resource that will be busy at times so  set-
              ting  this range to something too narrow might cause unnecessary
              connection setup failures.

              Example:
               curl --local-port 1000-3000 https://example.com

       --location-trusted
              (HTTP) Like -L, --location, but will allow sending  the  name  +
              password to all hosts that the site may redirect to. This may or
              may not introduce a security breach if the site redirects you to
              a site to which you will send your authentication info (which is
              plaintext in the case of HTTP Basic authentication).

              Example:
               curl --location-trusted -u user:password https://example.com

              See also -u, --user.

       -L, --location
              (HTTP) If the server reports that the requested page  has  moved
              to a different location (indicated with a Location: header and a
              3XX response code), this option will make curl redo the  request
              on  the  new  place.  If used together with -i, --include or -I,
              --head, headers from all requested pages  will  be  shown.  When
              authentication  is  used, curl only sends its credentials to the
              initial host. If a redirect takes curl to a different  host,  it
              will  not  be  able  to  intercept  the  user+password. See also
              --location-trusted on how to change  this.  You  can  limit  the
              amount  of redirects to follow by using the --max-redirs option.

              When curl follows a redirect and if the request is  a  POST,  it
              will  send the following request with a GET if the HTTP response
              was 301, 302, or 303. If the response code  was  any  other  3x
              code,  curl  will  re-send  the following request using the same
              unmodified method.

              You can tell curl to not change POST requests to GET after a 30x
              response  by  using  the  dedicated options for that: --post301,
              --post302 and --post303.

              The method set with -X,  --request  overrides  the  method  curl
              would otherwise select to use.

              Example:
               curl -L https://example.com

       --login-options <options>
              (IMAP  POP3 SMTP) Specify the login options to use during server
              authentication.

              You can use login options to specify protocol  specific  options
              that  may  be  used during authentication. At present only IMAP,
              POP3 and SMTP support login options. For more information  about
              login  options  please  see  RFC  2384,  RFC 5092 and IETF draft
              draft-earhart-url-smtp-00.txt

              If this option is used several times, the last one will be used.

              Example:
               curl --login-options 'AUTH=*' imap://example.com

              Added in 7.34.0.

       --mail-auth <address>
              (SMTP)  Specify  a  single address. This will be used to specify
              the authentication address (identity)  of  a  submitted  message
              that is being relayed to another server.

              Example:
               curl --mail-auth user@example.come -T mail smtp://example.com/

              See also --mail-rcpt and --mail-from.

       --mail-from <address>
              (SMTP)  Specify  a single address that the given mail should get
              sent from.

              Example:
               curl --mail-from user@example.com -T mail smtp://example.com/

              See also --mail-rcpt and --mail-auth.

       --mail-rcpt-allowfails
              (SMTP) When sending data to multiple recipients, by default curl
              will  abort  SMTP conversation if at least one of the recipients
              causes RCPT TO command to return an error.

              The default behavior can  be  changed  by  passing  --mail-rcpt-
              allowfails  command-line  option  which  will  make  curl ignore
              errors and proceed with the remaining valid recipients.

              If all recipients trigger RCPT TO  failures  and  this  flag  is
              specified,  curl  will  still  abort  the  SMTP conversation and
              return the error received from to the last RCPT TO command.

              Example:
               curl --mail-rcpt-allowfails --mail-rcpt dest@example.com smtp://example.com

              Added in 7.69.0.

       --mail-rcpt <address>
              (SMTP) Specify a single e-mail address,  user  name  or  mailing
              list  name. Repeat this option several times to send to multiple
              recipients.

              When performing an  address  verification  (VRFY  command),  the
              recipient  should be specified as the user name or user name and
              domain (as per Section 3.5 of RFC5321). (Added in 7.34.0)

              When performing a mailing list expand (EXPN command), the recip-
              ient  should  be  specified using the mailing list name, such as
              "Friends" or "London-Office".  (Added in 7.34.0)

              Example:
               curl --mail-rcpt user@example.net smtp://example.com

       -M, --manual
              Manual. Display the huge help text.

              Example:
               curl --manual

       --max-filesize <bytes>
              (FTP HTTP MQTT) Specify the maximum size (in bytes) of a file to
              download.  If  the file requested is larger than this value, the
              transfer will not start and curl will return with exit code  63.

              A  size  modifier may be used. For example, Appending 'k' or 'K'
              will count  the  number  as  kilobytes,  'm'  or  'M'  makes  it
              megabytes,  while 'g' or 'G' makes it gigabytes. Examples: 200K,
              3m and 1G. (Added in 7.58.0)

              NOTE: The file size is not always known prior to  download,  and
              for such files this option has no effect even if the file trans-
              fer ends up being larger than this given limit.  Example:
               curl --max-filesize 100K https://example.com

              See also --limit-rate.

       --max-redirs <num>
              (HTTP) Set maximum number of redirections to  follow.  When  -L,
              --location  is  used,  to  prevent  curl from following too many
              redirects, by default, the limit is set  to  50  redirects.  Set
              this option to -1 to make it unlimited.

              If this option is used several times, the last one will be used.

              Example:
               curl --max-redirs 3 --location https://example.com

       -m, --max-time <fractional seconds>
              Maximum time in seconds that you allow the  whole  operation  to
              take.   This is useful for preventing your batch jobs from hang-
              ing for hours due to slow networks or links going  down.   Since
              7.32.0, this option accepts decimal values, but the actual time-
              out will decrease in accuracy as the specified timeout increases
              in decimal precision.

              If this option is used several times, the last one will be used.

              Examples:
               curl --max-time 10 https://example.com
               curl --max-time 2.92 https://example.com

              See also --connect-timeout.

       --metalink
              This option was previously used to specify a metalink  resource.
              Metalink  support  has  been  disabled  in curl since 7.78.0 for
              security reasons.

              Example:
               curl --metalink file https://example.com

       --negotiate
              (HTTP) Enables Negotiate (SPNEGO) authentication.

              This option requires a library built with GSS-API or  SSPI  sup-
              port.  Use  -V,  --version  to  see  if  your curl supports GSS-
              API/SSPI or SPNEGO.

              When using this option, you must also provide a fake -u,  --user
              option  to  activate the authentication code properly. Sending a
              '-u :' is enough as the user name  and  password  from  the  -u,
              --user option are not actually used.

              If  this  option  is  used  several times, only the first one is
              used.

              Example:
               curl --negotiate -u : https://example.com

              See also --basic, --ntlm, --anyauth and --proxy-negotiate.

       --netrc-file <filename>
              This option is similar to -n, --netrc, except that  you  provide
              the  path  (absolute  or  relative)  to the netrc file that curl
              should use.  You can only specify one netrc file per invocation.
              If  several --netrc-file options are provided, the last one will
              be used.

              It will abide by --netrc-optional if specified.

              Example:
               curl --netrc-file netrc https://example.com

              This option overrides -n, --netrc.

       --netrc-optional
              Similar to -n, --netrc, but this option makes the  .netrc  usage
              optional and not mandatory as the -n, --netrc option does.

              Example:
               curl --netrc-optional https://example.com

              See also --netrc-file. This option overrides -n, --netrc.

       -n, --netrc
              Makes  curl  scan  the  .netrc  (_netrc  on Windows) file in the
              user's home directory for login name and password. This is typi-
              cally  used for FTP on Unix. If used with HTTP, curl will enable
              user authentication. See netrc(5) and ftp(1) for details on  the
              file  format.  Curl will not complain if that file does not have
              the right permissions (it should be neither  world-  nor  group-
              readable).  The  environment variable "HOME" is used to find the
              home directory.

              A quick and simple example of how to setup  a  .netrc  to  allow
              curl  to  FTP  to  the  machine  host.domain.com  with user name
              'myself' and password 'secret' should look similar to:

              machine host.domain.com login myself password secret

              Example:
               curl --netrc https://example.com

       -:, --next
              Tells curl to use a separate operation for the following URL and
              associated   options.  This  allows  you  to  send  several  URL
              requests, each with their own  specific  options,  for  example,
              such as different user names or custom requests for each.

              -:,  --next  will  reset  all local options and only global ones
              will have their values survive over to the  operation  following
              the  -:,  --next  instruction. Global options include -v, --ver-
              bose, --trace, --trace-ascii and --fail-early.

              For example, you can do both a GET and a POST in a  single  com-
              mand line:

               curl www1.example.com --next -d postthis www2.example.com

              Examples:
               curl https://example.com --next -d postthis www2.example.com
               curl -I https://example.com --next https://example.net/

              Added in 7.36.0.

       --no-alpn
              (HTTPS)  Disable  the  ALPN  TLS  extension.  ALPN is enabled by
              default if libcurl was built with an SSL library  that  supports
              ALPN.  ALPN is used by a libcurl that supports HTTP/2 to negoti-
              ate HTTP/2 support with the server during https sessions.

              Example:
               curl --no-alpn https://example.com

              See also --no-npn  and  --http2.  --no-alpn  requires  that  the
              underlying libcurl was built to support TLS. Added in 7.36.0.

       -N, --no-buffer
              Disables the buffering of the output stream. In normal work sit-
              uations, curl will use a standard buffered  output  stream  that
              will have the effect that it will output the data in chunks, not
              necessarily exactly when the data arrives.   Using  this  option
              will disable that buffering.

              Note  that  this  is the negated option name documented. You can
              thus use --buffer to enforce the buffering.

              Example:
               curl --no-buffer https://example.com

       --no-keepalive
              Disables the use of keepalive messages on  the  TCP  connection.
              curl otherwise enables them by default.

              Note  that  this  is the negated option name documented. You can
              thus use --keepalive to enforce keepalive.

              Example:
               curl --no-keepalive https://example.com

       --no-npn
              (HTTPS) Disable the NPN TLS extension. NPN is enabled by default
              if  libcurl was built with an SSL library that supports NPN. NPN
              is used by a libcurl that supports HTTP/2  to  negotiate  HTTP/2
              support with the server during https sessions.

              Example:
               curl --no-npn https://example.com

              See  also  --no-alpn  and  --http2.  --no-npn  requires that the
              underlying libcurl was built to support TLS. Added in 7.36.0.

       --no-progress-meter
              Option to switch off the progress meter output without muting or
              otherwise  affecting warning and informational messages like -s,
              --silent does.

              Note that this is the negated option name  documented.  You  can
              thus use --progress-meter to enable the progress meter again.

              Example:
               curl --no-progress-meter -o store https://example.com

              See also -v, --verbose and -s, --silent. Added in 7.67.0.

       --no-sessionid
              (TLS)  Disable curl's use of SSL session-ID caching.  By default
              all transfers are done using the cache. Note that while  nothing
              should  ever  get  hurt  by attempting to reuse SSL session-IDs,
              there seem to be broken SSL implementations in the wild that may
              require you to disable this in order for you to succeed.

              Note  that  this  is the negated option name documented. You can
              thus use --sessionid to enforce session-ID caching.

              Example:
               curl --no-sessionid https://example.com

       --noproxy <no-proxy-list>
              Comma-separated list of hosts for which not to use a  proxy,  if
              one  is  specified.  The  only wildcard is a single * character,
              which matches all hosts, and  effectively  disables  the  proxy.
              Each  name in this list is matched as either a domain which con-
              tains  the  hostname,  or  the  hostname  itself.  For  example,
              local.com    would    match    local.com,    local.com:80,   and
              www.local.com, but not www.notlocal.com.

              Since 7.53.0, This option overrides  the  environment  variables
              that  disable  the proxy ('no_proxy' and 'NO_PROXY'). If there's
              an environment variable disabling  a  proxy,  you  can  set  the
              noproxy list to "" to override it.

              Example:
               curl --noproxy "www.example" https://example.com

       --ntlm-wb
              (HTTP) Enables NTLM much in the style --ntlm does, but hand over
              the authentication to the separate binary  ntlmauth  application
              that is executed when needed.

              Example:
               curl --ntlm-wb -u user:password https://example.com

              See also --ntlm and --proxy-ntlm.

       --ntlm (HTTP)  Enables  NTLM  authentication.  The  NTLM authentication
              method was designed by Microsoft and is used by IIS web servers.
              It  is a proprietary protocol, reverse-engineered by clever peo-
              ple and implemented in curl based on their efforts. This kind of
              behavior  should  not be endorsed, you should encourage everyone
              who uses NTLM to switch to a public and  documented  authentica-
              tion method instead, such as Digest.

              If  you  want to enable NTLM for your proxy authentication, then
              use --proxy-ntlm.

              If this option is used several times,  only  the  first  one  is
              used.

              Example:
               curl --ntlm -u user:password https://example.com

              See  also  --proxy-ntlm.  --ntlm  requires  that  the underlying
              libcurl was built to support TLS. This option overrides  --basic
              and --negotiate and --digest and --anyauth.

       --oauth2-bearer <token>
              (IMAP  POP3  SMTP  HTTP)  Specify the Bearer Token for OAUTH 2.0
              server authentication. The Bearer Token is used  in  conjunction
              with  the  user name which can be specified as part of the --url
              or -u, --user options.

              The Bearer Token and user name are formatted  according  to  RFC
              6750.

              If this option is used several times, the last one will be used.

              Example:
               curl --oauth2-bearer "mF_9.B5f-4.1JqM" https://example.com

              Added in 7.33.0.

       --output-dir <dir>

              This option specifies the directory in  which  files  should  be
              stored, when -O, --remote-name or -o, --output are used.

              The  given  output  directory  is  used  for all URLs and output
              options on the command line, up until the first -:, --next.

              If the specified target directory does not exist, the  operation
              will fail unless --create-dirs is also used.

              If this option is used multiple times, the last specified direc-
              tory will be used.

              Example:
               curl --output-dir "tmp" -O https://example.com

              See also -O, --remote-name and -J,  --remote-header-name.  Added
              in 7.73.0.

       -o, --output <file>
              Write output to <file> instead of stdout. If you are using {} or
              [] to fetch multiple documents, you should quote the URL and you
              can  use  '#' followed by a number in the <file> specifier. That
              variable will be replaced with the current string  for  the  URL
              being fetched. Like in:

               curl "http://{one,two}.example.com" -o "file_#1.txt"

              or use several variables like:

               curl "http://{site,host}.host[1-5].com" -o "#1_#2"

              You  may use this option as many times as the number of URLs you
              have. For example, if you specify two URLs on the  same  command
              line, you can use it like this:

                curl -o aa example.com -o bb example.net

              and  the  order  of the -o options and the URLs does not matter,
              just that the first -o is for the first URL and so  on,  so  the
              above command line can also be written as

                curl example.com example.net -o aa -o bb

              See  also  the --create-dirs option to create the local directo-
              ries dynamically. Specifying the output as '-' (a  single  dash)
              will force the output to be done to stdout.

              To   suppress  response  bodies,  you  can  redirect  output  to
              /dev/null:

                curl example.com -o /dev/null

              Or for Windows use nul:

                curl example.com -o nul

              Examples:
               curl -o file https://example.com
               curl "http://{one,two}.example.com" -o "file_#1.txt"
               curl "http://{site,host}.host[1-5].com" -o "#1_#2"
               curl -o file https://example.com -o file2 https://example.net

              See also -O, --remote-name, --remote-name-all and -J,  --remote-
              header-name.

       --parallel-immediate
              When  doing  parallel  transfers, this option will instruct curl
              that it should rather prefer opening up more connections in par-
              allel at once rather than waiting to see if new transfers can be
              added as multiplexed streams on another connection.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --parallel-immediate -Z https://example.com -o file1 https://example.com -o file2

              See also -Z, --parallel and --parallel-max. Added in 7.68.0.

       --parallel-max <num>
              When  asked to do parallel transfers, using -Z, --parallel, this
              option controls the maximum amount of transfers to do simultane-
              ously.

              This option is global and does not need to be specified for each
              use of -:, --next.

              The default is 50.

              Example:
               curl --parallel-max 100 -Z https://example.com ftp://example.com/

              See also -Z, --parallel. Added in 7.66.0.

       -Z, --parallel
              Makes curl perform its transfers in parallel as compared to  the
              regular serial manner.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --parallel https://example.com -o file1 https://example.com -o file2

              Added in 7.66.0.

       --pass <phrase>
              (SSH TLS) Passphrase for the private key.

              If this option is used several times, the last one will be used.

              Example:
               curl --pass secret --key file https://example.com

       --path-as-is
              Tell  curl  to  not handle sequences of /../ or /./ in the given
              URL path. Normally curl will squash or merge them  according  to
              standards but with this option set you tell it not to do that.

              Example:
               curl --path-as-is https://example.com/../../etc/passwd

              Added in 7.42.0.

       --pinnedpubkey <hashes>
              (TLS)  Tells  curl  to  use  the  specified  public key file (or
              hashes) to verify the peer. This can be a path to a  file  which
              contains a single public key in PEM or DER format, or any number
              of base64 encoded sha256 hashes preceded by 'sha256//' and sepa-
              rated by ';'.

              When  negotiating  a  TLS  or SSL connection, the server sends a
              certificate indicating its identity. A public key  is  extracted
              from  this certificate and if it does not exactly match the pub-
              lic key provided to this option, curl will abort the  connection
              before sending or receiving any data.

              PEM/DER support:

              7.39.0: OpenSSL, GnuTLS and GSKit

              7.43.0: NSS and wolfSSL

              7.47.0: mbedtls

              sha256 support:

              7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL

              7.47.0: mbedtls

              Other SSL backends not supported.

              If this option is used several times, the last one will be used.

              Examples:
               curl --pinnedpubkey keyfile https://example.com
               curl --pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com

              Added in 7.39.0.

       --post301
              (HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST
              requests into GET requests when following a 301 redirection. The
              non-RFC behavior is ubiquitous in web browsers, so curl does the
              conversion by default to maintain consistency. However, a server
              may require a POST to remain a POST after  such  a  redirection.
              This option is meaningful only when using -L, --location.

              Example:
               curl --post301 --location -d "data" https://example.com

              See also --post302, --post303 and -L, --location.

       --post302
              (HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST
              requests into GET requests when following a 302 redirection. The
              non-RFC behavior is ubiquitous in web browsers, so curl does the
              conversion by default to maintain consistency. However, a server
              may  require  a  POST to remain a POST after such a redirection.
              This option is meaningful only when using -L, --location.

              Example:
               curl --post302 --location -d "data" https://example.com

              See also --post301, --post303 and -L, --location.

       --post303
              (HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert POST
              requests  into  GET  requests when following 303 redirections. A
              server may require a POST to remain a POST after a 303 redirect-
              ion. This option is meaningful only when using -L, --location.

              Example:
               curl --post303 --location -d "data" https://example.com

              See also --post302, --post301 and -L, --location.

       --preproxy [protocol://]host[:port]
              Use  the  specified  SOCKS proxy before connecting to an HTTP or
              HTTPS -x, --proxy. In such a case curl  first  connects  to  the
              SOCKS  proxy  and  then  connects (through SOCKS) to the HTTP or
              HTTPS proxy. Hence pre proxy.

              The pre proxy string should be specified with a protocol:// pre-
              fix  to  specify  alternative  proxy  protocols.  Use socks4://,
              socks4a://, socks5:// or  socks5h://  to  request  the  specific
              SOCKS  version  to be used. No protocol specified will make curl
              default to SOCKS4.

              If the port number is not specified in the proxy string,  it  is
              assumed to be 1080.

              User and password that might be provided in the proxy string are
              URL decoded by curl. This allows you to pass in special  charac-
              ters such as @ by using %40 or pass in a colon with %3a.

              If this option is used several times, the last one will be used.

              Example:
               curl --preproxy socks5://proxy.example -x http://http.example https://example.com

              Added in 7.52.0.

       -#, --progress-bar
              Make curl display transfer progress as  a  simple  progress  bar
              instead of the standard, more informational, meter.

              This  progress  bar draws a single line of '#' characters across
              the screen and shows a percentage if the transfer size is known.
              For  transfers  without  a  known size, there will be space ship
              (-=o=-) that moves back and forth but only while data  is  being
              transferred, with a set of flying hash sign symbols on top.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl -# -O https://example.com

       --proto-default <protocol>
              Tells curl to use protocol for any URL missing a scheme name.

              An unknown or unsupported  protocol  causes  error  CURLE_UNSUP-
              PORTED_PROTOCOL (1).

              This option does not change the default proxy protocol (http).

              Without this option set, curl guesses protocol based on the host
              name, see --url for details.

              Example:
               curl --proto-default https ftp.example.com

              Added in 7.45.0.

       --proto-redir <protocols>
              Tells curl to limit what protocols it may use on redirect.  Pro-
              tocols  denied by --proto are not overridden by this option. See
              --proto for how protocols are represented.

              Example, allow only HTTP and HTTPS on redirect:

               curl --proto-redir -all,http,https http://example.com

              By default curl will only allow HTTP, HTTPS, FTP and FTPS on re-
              direct (since 7.65.2). Specifying all or +all enables all proto-
              cols on redirects, which is not good for security.

              Example:
               curl --proto-redir =http,https https://example.com

       --proto <protocols>
              Tells curl to limit what protocols it  may  use  for  transfers.
              Protocols  are evaluated left to right, are comma separated, and
              are each a protocol name or 'all', optionally prefixed  by  zero
              or more modifiers. Available modifiers are:

              +  Permit this protocol in addition to protocols already permit-
                 ted (this is the default if no modifier is used).

              -  Deny this protocol, removing it from the  list  of  protocols
                 already permitted.

              =  Permit  only this protocol (ignoring the list already permit-
                 ted), though subject  to  later  modification  by  subsequent
                 entries in the comma separated list.

              For example:

              --proto -ftps  uses the default protocols, but disables ftps

              --proto -all,https,+http
                             only enables http and https

              --proto =http,https
                             also only enables http and https

              Unknown  protocols  produce  a  warning.  This allows scripts to
              safely rely on being able to disable potentially dangerous  pro-
              tocols,  without  relying  upon  support for that protocol being
              built into curl to avoid an error.

              This option can be used multiple times, in which case the effect
              is  the same as concatenating the protocols into one instance of
              the option.

              Example:
               curl --proto =http,https,sftp https://example.com

              See also --proto-redir and --proto-default.

       --proxy-anyauth
              Tells curl to pick a suitable authentication method when  commu-
              nicating  with  the  given HTTP proxy. This might cause an extra
              request/response round-trip.

              Example:
               curl --proxy-anyauth --proxy-user user:passwd -x proxy https://example.com

              See also -x, --proxy, --proxy-basic and --proxy-digest.

       --proxy-basic
              Tells curl to use HTTP Basic authentication  when  communicating
              with the given proxy. Use --basic for enabling HTTP Basic with a
              remote host. Basic is the  default  authentication  method  curl
              uses with proxies.

              Example:
               curl --proxy-basic --proxy-user user:passwd -x proxy https://example.com

              See also -x, --proxy, --proxy-anyauth and --proxy-digest.

       --proxy-cacert <file>
              Same as --cacert but used in HTTPS proxy context.

              Example:
               curl --proxy-cacert CA-file.txt -x https://proxy https://example.com

              See  also  --proxy-capath,  --cacert,  --capath and -x, --proxy.
              Added in 7.52.0.

       --proxy-capath <dir>
              Same as --capath but used in HTTPS proxy context.

              Example:
               curl --proxy-capath /local/directory -x https://proxy https://example.com

              See also --proxy-cacert, -x,  --proxy  and  --capath.  Added  in
              7.52.0.

       --proxy-cert-type <type>
              Same as --cert-type but used in HTTPS proxy context.

              Example:
               curl --proxy-cert-type PEM --proxy-cert file -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-cert <cert[:passwd]>
              Same as -E, --cert but used in HTTPS proxy context.

              Example:
               curl --proxy-cert file -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-ciphers <list>
              Same as --ciphers but used in HTTPS proxy context.

              Example:
               curl --proxy-ciphers ECDHE-ECDSA-AES256-CCM8 -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-crlfile <file>
              Same as --crlfile but used in HTTPS proxy context.

              Example:
               curl --proxy-crlfile rejects.txt -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-digest
              Tells  curl to use HTTP Digest authentication when communicating
              with the given proxy. Use --digest for enabling HTTP Digest with
              a remote host.

              Example:
               curl --proxy-digest --proxy-user user:passwd -x proxy https://example.com

              See also -x, --proxy, --proxy-anyauth and --proxy-basic.

       --proxy-header <header/@file>
              (HTTP)  Extra header to include in the request when sending HTTP
              to a proxy. You may specify any number of extra headers. This is
              the  equivalent option to -H, --header but is for proxy communi-
              cation only like in CONNECT requests when you  want  a  separate
              header  sent  to  the proxy to what is sent to the actual remote
              host.

              curl will make sure that each header  you  add/replace  is  sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              Headers  specified  with  this  option  will  not be included in
              requests that curl knows will not be sent to a proxy.

              Starting in 7.55.0, this option can take an argument  in  @file-
              name  style, which then adds a header for each line in the input
              file. Using @- will make curl read the header file from stdin.

              This option can be used  multiple  times  to  add/replace/remove
              multiple headers.

              Examples:
               curl --proxy-header "X-First-Name: Joe" -x http://proxy https://example.com
               curl --proxy-header "User-Agent: surprise" -x http://proxy https://example.com
               curl --proxy-header "Host:" -x http://proxy https://example.com

              Added in 7.37.0.

       --proxy-insecure
              Same as -k, --insecure but used in HTTPS proxy context.

              Example:
               curl --proxy-insecure -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-key-type <type>
              Same as --key-type but used in HTTPS proxy context.

              Example:
               curl --proxy-key-type DER --proxy-key here -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-key <key>
              Same as --key but used in HTTPS proxy context.

              Example:
               curl --proxy-key here -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-negotiate
              Tells  curl  to  use HTTP Negotiate (SPNEGO) authentication when
              communicating with the given proxy. Use --negotiate for enabling
              HTTP Negotiate (SPNEGO) with a remote host.

              Example:
               curl --proxy-negotiate --proxy-user user:passwd -x proxy https://example.com

              See also --proxy-anyauth and --proxy-basic.

       --proxy-ntlm
              Tells  curl  to  use HTTP NTLM authentication when communicating
              with the given proxy. Use --ntlm for enabling NTLM with a remote
              host.

              Example:
               curl --proxy-ntlm --proxy-user user:passwd -x http://proxy https://example.com

              See also --proxy-negotiate and --proxy-anyauth.

       --proxy-pass <phrase>
              Same as --pass but used in HTTPS proxy context.

              Example:
               curl --proxy-pass secret --proxy-key here -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-pinnedpubkey <hashes>
              (TLS)  Tells  curl  to  use  the  specified  public key file (or
              hashes) to verify the proxy. This can be a path to a file  which
              contains a single public key in PEM or DER format, or any number
              of base64 encoded sha256 hashes preceded by 'sha256//' and sepa-
              rated by ';'.

              When  negotiating  a  TLS  or SSL connection, the server sends a
              certificate indicating its identity. A public key  is  extracted
              from  this certificate and if it does not exactly match the pub-
              lic key provided to this option, curl will abort the  connection
              before sending or receiving any data.

              If this option is used several times, the last one will be used.

              Examples:
               curl --proxy-pinnedpubkey keyfile https://example.com
               curl --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com

              Added in 7.59.0.

       --proxy-service-name <name>
              This option allows you to change  the  service  name  for  proxy
              negotiation.

              Example:
               curl --proxy-service-name "shrubbery" -x proxy https://example.com

              Added in 7.43.0.

       --proxy-ssl-allow-beast
              Same as --ssl-allow-beast but used in HTTPS proxy context.

              Example:
               curl --proxy-ssl-allow-beast -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-ssl-auto-client-cert
              Same  as --ssl-auto-client-cert but used in HTTPS proxy context.

              Example:
               curl --proxy-ssl-auto-client-cert -x https://proxy https://example.com

              Added in 7.77.0.

       --proxy-tls13-ciphers <ciphersuite list>
              (TLS) Specifies which cipher suites to use in the connection  to
              your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers
              suites must specify valid ciphers. Read up  on  TLS  1.3  cipher
              suite details on this URL:

               https://curl.se/docs/ssl-ciphers.html

              This  option  is  currently  used only when curl is built to use
              OpenSSL 1.1.1 or later. If you are using a different SSL backend
              you  can try setting TLS 1.3 cipher suites by using the --proxy-
              ciphers option.

              If this option is used several times, the last one will be used.

              Example:
               curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy https://example.com

              Added in 7.61.0.

       --proxy-tlsauthtype <type>
              Same as --tlsauthtype but used in HTTPS proxy context.

              Example:
               curl --proxy-tlsauthtype SRP -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-tlspassword <string>
              Same as --tlspassword but used in HTTPS proxy context.

              Example:
               curl --proxy-tlspassword passwd -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-tlsuser <name>
              Same as --tlsuser but used in HTTPS proxy context.

              Example:
               curl --proxy-tlsuser smith -x https://proxy https://example.com

              Added in 7.52.0.

       --proxy-tlsv1
              Same as -1, --tlsv1 but used in HTTPS proxy context.

              Example:
               curl --proxy-tlsv1 -x https://proxy https://example.com

              Added in 7.52.0.

       -U, --proxy-user <user:password>
              Specify  the user name and password to use for proxy authentica-
              tion.

              If you use a Windows SSPI-enabled  curl  binary  and  do  either
              Negotiate  or  NTLM  authentication  then  you  can tell curl to
              select the user name and password from your environment by spec-
              ifying a single colon with this option: "-U :".

              On systems where it works, curl will hide the given option argu-
              ment from process listings. This is not enough to  protect  cre-
              dentials  from  possibly getting seen by other users on the same
              system as they will still be visible for a brief  moment  before
              cleared.  Such  sensitive  data  should be retrieved from a file
              instead or similar and never used in clear  text  in  a  command
              line.

              If this option is used several times, the last one will be used.

              Example:
               curl --proxy-user name:pwd -x proxy https://example.com

       -x, --proxy [protocol://]host[:port]
              Use the specified proxy.

              The proxy string can be specified with a protocol:// prefix.  No
              protocol specified or http:// will be treated as HTTP proxy. Use
              socks4://, socks4a://, socks5:// or socks5h:// to request a spe-
              cific SOCKS version to be used.


              HTTPS  proxy  support  via https:// protocol prefix was added in
              7.52.0 for OpenSSL, GnuTLS and NSS.

              Unrecognized and unsupported  proxy  protocols  cause  an  error
              since  7.52.0.   Prior  versions may ignore the protocol and use
              http:// instead.

              If the port number is not specified in the proxy string,  it  is
              assumed to be 1080.

              This  option  overrides  existing environment variables that set
              the proxy to use. If there's an environment variable  setting  a
              proxy, you can set proxy to "" to override it.

              All operations that are performed over an HTTP proxy will trans-
              parently be converted to HTTP. It means  that  certain  protocol
              specific operations might not be available. This is not the case
              if you can tunnel through the proxy, as one with the -p, --prox-
              ytunnel option.

              User and password that might be provided in the proxy string are
              URL decoded by curl. This allows you to pass in special  charac-
              ters such as @ by using %40 or pass in a colon with %3a.

              The  proxy host can be specified the exact same way as the proxy
              environment variables, including the protocol  prefix  (http://)
              and the embedded user + password.

              If this option is used several times, the last one will be used.

              Example:
               curl --proxy http://proxy.example https://example.com

       --proxy1.0 <host[:port]>
              Use the specified HTTP 1.0 proxy. If  the  port  number  is  not
              specified, it is assumed at port 1080.

              The  only  difference between this and the HTTP proxy option -x,
              --proxy, is that attempts to use CONNECT through the proxy  will
              specify an HTTP 1.0 protocol instead of the default HTTP 1.1.

              Example:
               curl --proxy1.0 -x http://proxy https://example.com

       -p, --proxytunnel
              When  an  HTTP  proxy is used -x, --proxy, this option will make
              curl tunnel through the proxy. The tunnel approach is made  with
              the  HTTP  proxy  CONNECT  request  and  requires that the proxy
              allows direct connect to the remote port number  curl  wants  to
              tunnel through to.

              To  suppress  proxy CONNECT response headers when curl is set to
              output headers use --suppress-connect-headers.

              Example:
               curl --proxytunnel -x http://proxy https://example.com

              See also -x, --proxy.

       --pubkey <key>
              (SFTP SCP) Public key file name. Allows you to provide your pub-
              lic key in this separate file.

              If this option is used several times, the last one will be used.

              (As of 7.39.0, curl attempts to automatically extract the public
              key  from the private key file, so passing this option is gener-
              ally not required. Note that this public key extraction requires
              libcurl  to  be linked against a copy of libssh2 1.2.8 or higher
              that is itself linked against OpenSSL.)

              Example:
               curl --pubkey file.pub sftp://example.com/

       -Q, --quote <command>
              (FTP SFTP) Send an arbitrary command to the remote FTP  or  SFTP
              server.  Quote commands are sent BEFORE the transfer takes place
              (just after the initial PWD command in an FTP  transfer,  to  be
              exact). To make commands take place after a successful transfer,
              prefix them with a dash '-'.  To make  commands  be  sent  after
              curl has changed the working directory, just before the transfer
              command(s), prefix the command with a '+'  (this  is  only  sup-
              ported for FTP). You may specify any number of commands.

              By  default  curl  will stop at first failure. To make curl con-
              tinue even if the command fails,  prefix  the  command  with  an
              asterisk  (*).  Otherwise, if the server returns failure for one
              of the commands, the entire operation will be aborted.

              You must send syntactically correct  FTP  commands  as  RFC  959
              defines  to  FTP servers, or one of the commands listed below to
              SFTP servers.

              This option can be used multiple times.

              SFTP is a binary protocol. Unlike for FTP, curl interprets  SFTP
              quote  commands  itself before sending them to the server.  File
              names may be quoted shell-style to embed spaces or special char-
              acters.   Following is the list of all supported SFTP quote com-
              mands:

              atime date file
                     The atime command sets the last access time of  the  file
                     named  by  the file operand. The <date expression> can be
                     all sorts of date strings, see  the  curl_getdate(3)  man
                     page for date expression details. (Added in 7.73.0)

              chgrp group file
                     The  chgrp command sets the group ID of the file named by
                     the file operand to the group ID specified by  the  group
                     operand. The group operand is a decimal integer group ID.

              chmod mode file
                     The chmod command modifies the  file  mode  bits  of  the
                     specified file. The mode operand is an octal integer mode
                     number.

              chown user file
                     The chown command sets the owner of the file named by the
                     file  operand  to the user ID specified by the user oper-
                     and. The user operand is a decimal integer user ID.

              ln source_file target_file
                     The ln and symlink commands create a symbolic link at the
                     target_file  location  pointing  to the source_file loca-
                     tion.

              mkdir directory_name
                     The mkdir command creates  the  directory  named  by  the
                     directory_name operand.

              mtime date file
                     The  mtime command sets the last modification time of the
                     file named by the file operand. The <date expression> can
                     be all sorts of date strings, see the curl_getdate(3) man
                     page for date expression details. (Added in 7.73.0)

              pwd    The pwd command returns the absolute pathname of the cur-
                     rent working directory.

              rename source target
                     The rename command renames the file or directory named by
                     the source operand to the destination path named  by  the
                     target operand.

              rm file
                     The rm command removes the file specified by the file op-
                     erand.

              rmdir directory
                     The rmdir command removes the directory  entry  specified
                     by the directory operand, provided it is empty.

              symlink source_file target_file
                     See ln.

       Example:
        curl --quote "DELE file" ftp://example.com/foo

       --random-file <file>
              Specify the path name to file containing what will be considered
              as random data. The data may be used to seed the  random  engine
              for SSL connections.  See also the --egd-file option.

              Example:
               curl --random-file rubbish https://example.com

       -r, --range <range>
              (HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial docu-
              ment) from an HTTP/1.1, FTP or SFTP  server  or  a  local  FILE.
              Ranges can be specified in a number of ways.

              0-499     specifies the first 500 bytes

              500-999   specifies the second 500 bytes

              -500      specifies the last 500 bytes

              9500-     specifies the bytes from offset 9500 and forward

              0-0,-1    specifies the first and last byte only(*)(HTTP)

              100-199,500-599
                        specifies two separate 100-byte ranges(*) (HTTP)

              (*)  = NOTE that this will cause the server to reply with a mul-
              tipart response, which will be returned as-is by  curl!  Parsing
              or otherwise transforming this response is the responsibility of
              the caller.

              Only digit characters (0-9) are valid in the 'start' and  'stop'
              fields  of the 'start-stop' range syntax. If a non-digit charac-
              ter is given in the range, the server's response will be unspec-
              ified, depending on the server's configuration.

              You  should also be aware that many HTTP/1.1 servers do not have
              this feature enabled, so that when you attempt to get  a  range,
              you will instead get the whole document.

              FTP  and  SFTP  range  downloads only support the simple 'start-
              stop' syntax (optionally with one of the numbers  omitted).  FTP
              use depends on the extended FTP command SIZE.

              If this option is used several times, the last one will be used.

              Example:
               curl --range 22-44 https://example.com

       --raw  (HTTP) When used, it disables all internal HTTP decoding of con-
              tent  or  transfer  encodings  and  instead makes them passed on
              unaltered, raw.

              Example:
               curl --raw https://example.com

       -e, --referer <URL>
              (HTTP) Sends the "Referrer Page" information to the HTTP server.
              This can also be set with the -H, --header flag of course.  When
              used with -L, --location you  can  append  ";auto"  to  the  -e,
              --referer  URL  to  make curl automatically set the previous URL
              when it follows a Location: header. The ";auto"  string  can  be
              used alone, even if you do not set an initial -e, --referer.

              If this option is used several times, the last one will be used.

              Examples:
               curl --referer "https://fake.example" https://example.com
               curl --referer "https://fake.example;auto" -L https://example.com
               curl --referer ";auto" -L https://example.com

              See also -A, --user-agent and -H, --header.

       -J, --remote-header-name
              (HTTP) This option tells the -O, --remote-name option to use the
              server-specified   Content-Disposition   filename   instead   of
              extracting a filename from the URL.

              If the server specifies a file name and a file  with  that  name
              already  exists  in the current working directory it will not be
              overwritten and an error will occur.  If  the  server  does  not
              specify a file name then this option has no effect.

              There's  no  attempt to decode %-sequences (yet) in the provided
              file name, so this option may provide you with rather unexpected
              file names.

              WARNING:  Exercise  judicious  use of this option, especially on
              Windows. A rogue server could send you the  name  of  a  DLL  or
              other  file  that could possibly be loaded automatically by Win-
              dows or some third party software.

              Example:
               curl -OJ https://example.com/file

       --remote-name-all
              This option changes the default action for all given URLs to  be
              dealt with as if -O, --remote-name were used for each one. So if
              you want to disable that for a specific URL after --remote-name-
              all has been used, you must use "-o -" or --no-remote-name.

              Example:
               curl --remote-name-all ftp://example.com/file1 ftp://example.com/file2

       -O, --remote-name
              Write  output to a local file named like the remote file we get.
              (Only the file part of the remote file is used, the path is  cut
              off.)

              The  file will be saved in the current working directory. If you
              want the file saved in a  different  directory,  make  sure  you
              change  the  current working directory before invoking curl with
              this option.

              The remote file name to use for saving  is  extracted  from  the
              given  URL,  nothing  else,  and if it already exists it will be
              overwritten. If you want the server to be  able  to  choose  the
              file name refer to -J, --remote-header-name which can be used in
              addition to this option. If the server chooses a file  name  and
              that name already exists it will not be overwritten.

              There is no URL decoding done on the file name. If it has %20 or
              other URL encoded parts of the name, they will end up  as-is  as
              file name.

              You  may use this option as many times as the number of URLs you
              have.

              Example:
               curl -O https://example.com/filename

       -R, --remote-time
              When used, this will make curl attempt to figure out  the  time-
              stamp  of  the  remote  file,  and if that is available make the
              local file get that same timestamp.

              Example:
               curl --remote-time -o foo https://example.com

       --request-target <path>
              (HTTP) Tells curl to use an alternative "target" (path)  instead
              of  using  the  path as provided in the URL. Particularly useful
              when wanting to issue HTTP requests  without  leading  slash  or
              other  data  that  does not follow the regular URL pattern, like
              "OPTIONS *".

              Example:
               curl --request-target "*" -X OPTIONS https://example.com

              Added in 7.55.0.

       -X, --request <command>
              (HTTP) Specifies a custom request method to use when communicat-
              ing  with the HTTP server.  The specified request method will be
              used instead of the method otherwise  used  (which  defaults  to
              GET).  Read  the HTTP 1.1 specification for details and explana-
              tions. Common additional HTTP requests include PUT  and  DELETE,
              but related technologies like WebDAV offers PROPFIND, COPY, MOVE
              and more.

              Normally you do not need this option. All sorts  of  GET,  HEAD,
              POST and PUT requests are rather invoked by using dedicated com-
              mand line options.

              This option only changes  the  actual  word  used  in  the  HTTP
              request,  it does not alter the way curl behaves. So for example
              if you want to make a proper HEAD request, using  -X  HEAD  will
              not suffice. You need to use the -I, --head option.

              The  method  string  you set with -X, --request will be used for
              all requests, which if you for example use  -L,  --location  may
              cause  unintended side-effects when curl does not change request
              method according to the HTTP 30x response codes - and similar.

              (FTP) Specifies a custom FTP command to use instead of LIST when
              doing file lists with FTP.

              (POP3) Specifies a custom POP3 command to use instead of LIST or
              RETR.


              (IMAP) Specifies a custom IMAP command to use instead  of  LIST.
              (Added in 7.30.0)

              (SMTP) Specifies a custom SMTP command to use instead of HELP or
              VRFY. (Added in 7.34.0)

              If this option is used several times, the last one will be used.

              Examples:
               curl -X "DELETE" https://example.com
               curl -X NLST ftp://example.com/

       --resolve <[+]host:port:addr[,addr]...>
              Provide  a  custom  address  for  a specific host and port pair.
              Using this, you can make the curl requests(s)  use  a  specified
              address  and  prevent the otherwise normally resolved address to
              be used. Consider it a sort of /etc/hosts  alternative  provided
              on  the  command line. The port number should be the number used
              for the specific protocol the host will be used  for.  It  means
              you  need several entries if you want to provide address for the
              same host but different ports.

              By specifying '*' as host you can tell curl to resolve any  host
              and  specific  port  pair  to the specified address. Wildcard is
              resolved last so any --resolve with a  specific  host  and  port
              will be used first.

              The provided address set by this option will be used even if -4,
              --ipv4 or -6, --ipv6 is set to make curl use another IP version.

              By prefixing the host with a '+' you can make the entry time out
              after curl's default timeout (1 minute).  Note  that  this  will
              only  make  sense for long running parallel transfers with a lot
              of files. In such cases, if this option is used curl will try to
              resolve  the  host  as  it  normally  would once the timeout has
              expired.

              Support for providing the IP address within [brackets] was added
              in 7.57.0.

              Support  for providing multiple IP addresses per entry was added
              in 7.59.0.

              Support for resolving with wildcard was added in 7.64.0.

              Support for the '+' prefix was was added in 7.75.0.

              This option can be used many times to add  many  host  names  to
              resolve.

              Example:
               curl --resolve example.com:443:127.0.0.1 https://example.com

       --retry-all-errors
              Retry on any error. This option is used together with --retry.

              This  option  is the "sledgehammer" of retrying. Do not use this
              option by default (eg in curlrc), there may be unintended conse-
              quences  such as sending or receiving duplicate data. Do not use
              with redirected input or output. You'd be much better  off  han-
              dling  your  unique  problems  in  shell script. Please read the
              example below.

              WARNING: For server compatibility curl attempts to retry  failed
              flaky  transfers  as close as possible to how they were started,
              but this is not possible with redirected input  or  output.  For
              example,  before  retrying  it removes output data from a failed
              partial transfer that was written to  an  output  file.  However
              this is not true of data redirected to a | pipe or > file, which
              are not reset. We strongly suggest you do not  parse  or  record
              output  via  redirect in combination with this option, since you
              may receive duplicate data.

              By default curl will not error on an  HTTP  response  code  that
              indicates  an  HTTP  error,  if the transfer was successful. For
              example, if a server replies 404 Not  Found  and  the  reply  is
              fully  received  then that is not an error. When --retry is used
              then curl will retry on some HTTP response codes  that  indicate
              transient  HTTP  errors,  but  that  does  not  include most 4xx
              response codes such as 404. If you want to retry on all response
              codes  that indicate HTTP errors (4xx and 5xx) then combine with
              -f, --fail.

              Example:
               curl --retry-all-errors https://example.com

              Added in 7.71.0.

       --retry-connrefused
              In addition to the other conditions, consider ECONNREFUSED as  a
              transient  error  too  for --retry. This option is used together
              with --retry.

              Example:
               curl --retry-connrefused --retry https://example.com

              Added in 7.52.0.

       --retry-delay <seconds>
              Make curl sleep this amount of time before  each  retry  when  a
              transfer  has  failed  with  a  transient  error (it changes the
              default backoff time algorithm between retries). This option  is
              only  interesting if --retry is also used. Setting this delay to
              zero will make curl use the default backoff time.

              If this option is used several times, the last one will be used.

              Example:
               curl --retry-delay 5 --retry https://example.com

       --retry-max-time <seconds>
              The  retry  timer  is  reset  before the first transfer attempt.
              Retries will be done as usual (see --retry) as long as the timer
              has  not  reached this given limit. Notice that if the timer has
              not reached the limit, the request will be made and  while  per-
              forming,  it  may  take  longer  than this given time period. To
              limit a single request's maximum time, use -m, --max-time.   Set
              this option to zero to not timeout retries.

              If this option is used several times, the last one will be used.

              Example:
               curl --retry-max-time 30 --retry 10 https://example.com

       --retry <num>
              If a transient error is returned when curl tries  to  perform  a
              transfer,  it  will retry this number of times before giving up.
              Setting the number to 0 makes curl do no retries (which  is  the
              default).  Transient  error  means either: a timeout, an FTP 4xx
              response code or an HTTP 408, 429, 500, 502, 503 or 504 response
              code.

              When  curl  is about to retry a transfer, it will first wait one
              second and then for all forthcoming retries it will  double  the
              waiting  time until it reaches 10 minutes which then will be the
              delay between the rest of the retries.  By  using  --retry-delay
              you   disable  this  exponential  backoff  algorithm.  See  also
              --retry-max-time to limit the total time allowed for retries.

              Since curl  7.66.0,  curl  will  comply  with  the  Retry-After:
              response  header  if  one  was present to know when to issue the
              next retry.

              If this option is used several times, the last one will be used.

              Example:
               curl --retry 7 https://example.com

       --sasl-authzid <identity>
              Use  this  authorisation  identity  (authzid), during SASL PLAIN
              authentication,  in  addition  to  the  authentication  identity
              (authcid) as specified by -u, --user.

              If  the  option  is  not  specified,  the server will derive the
              authzid from the authcid, but if specified, and depending on the
              server  implementation,  it may be used to access another user's
              inbox, that the user has been granted access  to,  or  a  shared
              mailbox for example.

              Example:
               curl --sasl-authzid zid imap://example.com/

              Added in 7.66.0.

       --sasl-ir
              Enable initial response in SASL authentication.

              Example:
               curl --sasl-ir imap://example.com/

              Added in 7.31.0.

       --service-name <name>
              This option allows you to change the service name for SPNEGO.

              Examples:    --negotiate    --service-name   sockd   would   use
              sockd/server-name.

              Example:
               curl --service-name sockd/server https://example.com

              Added in 7.43.0.

       -S, --show-error
              When used with -s, --silent, it makes curl show an error message
              if it fails.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --show-error --silent https://example.com

              See also --no-progress-meter.

       -s, --silent
              Silent or quiet mode. Do not show progress meter or  error  mes-
              sages.   Makes  Curl mute. It will still output the data you ask
              for, potentially even to the terminal/stdout unless you redirect
              it.

              Use  -S,  --show-error  in  addition  to  this option to disable
              progress meter but still show error messages.

              Example:
               curl -s https://example.com

              See also -v, --verbose, --stderr and --no-progress-meter.

       --socks4 <host[:port]>
              Use the specified SOCKS4 proxy. If the port number is not speci-
              fied,  it  is  assumed at port 1080. Using this socket type make
              curl resolve the host name and passing the  address  on  to  the
              proxy.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              This option is superfluous since you can specify a socks4  proxy
              with -x, --proxy using a socks4:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the same time -x, --proxy is used with an HTTP/HTTPS  proxy.  In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Example:
               curl --socks4 hostname:4096 https://example.com

       --socks4a <host[:port]>
              Use the specified SOCKS4a proxy. If the port number is not spec-
              ified, it is assumed at  port  1080.  This  asks  the  proxy  to
              resolve the host name.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              This option is superfluous since you can specify a socks4a proxy
              with -x, --proxy using a socks4a:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the same time -x, --proxy is used with an HTTP/HTTPS  proxy.  In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Example:
               curl --socks4a hostname:4096 https://example.com

       --socks5-basic
              Tells curl to use username/password authentication when connect-
              ing to a SOCKS5 proxy.  The username/password authentication  is
              enabled  by  default.   Use  --socks5-gssapi  to  force  GSS-API
              authentication to SOCKS5 proxies.

              Example:
               curl --socks5-basic --socks5 hostname:4096 https://example.com

              Added in 7.55.0.

       --socks5-gssapi-nec
              As part of the GSS-API negotiation a protection mode is  negoti-
              ated.  RFC  1961 says in section 4.3/4.4 it should be protected,
              but the NEC  reference  implementation  does  not.   The  option
              --socks5-gssapi-nec  allows the unprotected exchange of the pro-
              tection mode negotiation.

              Example:
               curl --socks5-gssapi-nec --socks5 hostname:4096 https://example.com

       --socks5-gssapi-service <name>
              The default service name for a socks server is rcmd/server-fqdn.
              This option allows you to change it.

              Examples:   --socks5  proxy-name  --socks5-gssapi-service  sockd
              would use sockd/proxy-name --socks5 proxy-name  --socks5-gssapi-
              service  sockd/real-name  would  use  sockd/real-name  for cases
              where the proxy-name does not match the principal name.

              Example:
               curl --socks5-gssapi-service sockd --socks5 hostname:4096 https://example.com

       --socks5-gssapi
              Tells curl to use GSS-API authentication when  connecting  to  a
              SOCKS5  proxy.  The GSS-API authentication is enabled by default
              (if curl is compiled with GSS-API support).  Use  --socks5-basic
              to force username/password authentication to SOCKS5 proxies.

              Example:
               curl --socks5-gssapi --socks5 hostname:4096 https://example.com

              Added in 7.55.0.

       --socks5-hostname <host[:port]>
              Use  the  specified  SOCKS5 proxy (and let the proxy resolve the
              host name). If the port number is not specified, it  is  assumed
              at port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              This option is superfluous since you can specify a socks5  host-
              name  proxy with -x, --proxy using a socks5h:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Example:
               curl --socks5-hostname proxy.example:7000 https://example.com

       --socks5 <host[:port]>
              Use the specified SOCKS5 proxy  -  but  resolve  the  host  name
              locally.  If  the port number is not specified, it is assumed at
              port 1080.

              This option overrides any previous use of -x, --proxy,  as  they
              are mutually exclusive.

              This  option is superfluous since you can specify a socks5 proxy
              with -x, --proxy using a socks5:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              This option (as well as --socks4) does not work with IPV6,  FTPS
              or LDAP.

              Example:
               curl --socks5 proxy.example:7000 https://example.com

       -Y, --speed-limit <speed>
              If a download is slower than this given speed (in bytes per sec-
              ond) for speed-time seconds it gets aborted. speed-time  is  set
              with -y, --speed-time and is 30 if not set.

              If this option is used several times, the last one will be used.

              Example:
               curl --speed-limit 300 --speed-time 10 https://example.com

       -y, --speed-time <seconds>
              If a download is slower than speed-limit bytes per second during
              a speed-time period, the download gets aborted. If speed-time is
              used, the default speed-limit will be  1  unless  set  with  -Y,
              --speed-limit.

              This  option  controls  transfers  and thus will not affect slow
              connects etc. If this is a concern for you, try  the  --connect-
              timeout option.

              If this option is used several times, the last one will be used.

              Example:
               curl --speed-limit 300 --speed-time 10 https://example.com

       --ssl-allow-beast
              This option tells curl to not work around a security flaw in the
              SSL3 and TLS1.0 protocols known as BEAST.  If this option is not
              used, the SSL layer may use workarounds known to cause  interop-
              erability problems with some older SSL implementations.

              WARNING: this option loosens the SSL security, and by using this
              flag you ask for exactly that.

              Example:
               curl --ssl-allow-beast https://example.com

       --ssl-auto-client-cert
              Tell libcurl to automatically locate and use a  client  certifi-
              cate  for  authentication,  when  requested  by the server. This
              option is only supported for Schannel (the  native  Windows  SSL
              library).  Prior  to  7.77.0  this  was  the default behavior in
              libcurl with Schannel. Since the server can request any certifi-
              cate  that  supports client authentication in the OS certificate
              store it could be a privacy violation and unexpected.

              Example:
               curl --ssl-auto-client-cert https://example.com

              See also --proxy-ssl-auto-client-cert. Added in 7.77.0.

       --ssl-no-revoke
              (Schannel) This option tells curl to disable certificate revoca-
              tion checks.  WARNING: this option loosens the SSL security, and
              by using this flag you ask for exactly that.

              Example:
               curl --ssl-no-revoke https://example.com

              Added in 7.44.0.

       --ssl-reqd
              (FTP IMAP POP3 SMTP) Require SSL/TLS for the connection.  Termi-
              nates the connection if the server does not support SSL/TLS.

              This option was formerly known as --ftp-ssl-reqd.

              Example:
               curl --ssl-reqd ftp://example.com

       --ssl-revoke-best-effort
              (Schannel)  This option tells curl to ignore certificate revoca-
              tion checks when they failed due to missing/offline distribution
              points for the revocation check lists.

              Example:
               curl --ssl-revoke-best-effort https://example.com

              Added in 7.70.0.

       --ssl  (FTP  IMAP  POP3  SMTP)  Try  to use SSL/TLS for the connection.
              Reverts to a non-secure connection if the server does  not  sup-
              port  SSL/TLS.   See  also  --ftp-ssl-control and --ssl-reqd for
              different levels of encryption required.

              This option was formerly known as --ftp-ssl.  That  option  name
              can still be used but will be removed in a future version.

              Example:
               curl --ssl pop3://example.com/

       -2, --sslv2
              (SSL) This option previously asked curl to use SSLv2, but start-
              ing in curl 7.77.0 this instruction is ignored. SSLv2 is  widely
              considered insecure (see RFC 6176).

              Example:
               curl --sslv2 https://example.com

              See  also  --http1.1  and --http2. -2, --sslv2 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides -3, --sslv3 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       -3, --sslv3
              (SSL) This option previously asked curl to use SSLv3, but start-
              ing in curl 7.77.0 this instruction is ignored. SSLv3 is  widely
              considered insecure (see RFC 7568).

              Example:
               curl --sslv3 https://example.com

              See  also  --http1.1  and --http2. -3, --sslv3 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides -2, --sslv2 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       --stderr <file>
              Redirect  all writes to stderr to the specified file instead. If
              the file name is a plain '-', it is instead written to stdout.

              This option is global and does not need to be specified for each
              use of -:, --next.

              If this option is used several times, the last one will be used.

              Example:
               curl --stderr output.txt https://example.com

              See also -v, --verbose and -s, --silent.

       --styled-output
              Enables the automatic use of bold font styles when writing  HTTP
              headers  to  the terminal. Use --no-styled-output to switch them
              off.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --styled-output -I https://example.com

              Added in 7.61.0.

       --suppress-connect-headers
              When  -p, --proxytunnel is used and a CONNECT request is made do
              not output proxy CONNECT response headers. This option is  meant
              to  be  used  with  -D, --dump-header or -i, --include which are
              used to show protocol headers in the output. It has no effect on
              debug  options  such as -v, --verbose or --trace, or any statis-
              tics.

              Example:
               curl --suppress-connect-headers --include -x proxy https://example.com

              See also -D, --dump-header, -i, --include and -p, --proxytunnel.
              Added in 7.54.0.

       --tcp-fastopen
              Enable use of TCP Fast Open (RFC7413).

              Example:
               curl --tcp-fastopen https://example.com

              Added in 7.49.0.

       --tcp-nodelay
              Turn  on the TCP_NODELAY option. See the curl_easy_setopt(3) man
              page for details about this option.

              Since 7.50.2, curl sets this option by default and you  need  to
              explicitly switch it off if you do not want it on.

              Example:
               curl --tcp-nodelay https://example.com

       -t, --telnet-option <opt=val>
              Pass options to the telnet protocol. Supported options are:

              TTYPE=<term> Sets the terminal type.

              XDISPLOC=<X display> Sets the X display location.

              NEW_ENV=<var,val> Sets an environment variable.

              Example:
               curl -t TTYPE=vt100 telnet://example.com/

       --tftp-blksize <value>
              (TFTP) Set TFTP BLKSIZE option (must be >512). This is the block
              size that curl will try to use when transferring data to or from
              a TFTP server. By default 512 bytes will be used.

              If this option is used several times, the last one will be used.

              Example:
               curl --tftp-blksize 1024 tftp://example.com/file

       --tftp-no-options
              (TFTP) Tells curl not to send TFTP options requests.

              This option improves interop with some legacy  servers  that  do
              not  acknowledge  or  properly implement TFTP options. When this
              option is used --tftp-blksize is ignored.

              Example:
               curl --tftp-no-options tftp://192.168.0.1/

              Added in 7.48.0.

       -z, --time-cond <time>
              (HTTP FTP) Request a file that has been modified later than  the
              given  time  and date, or one that has been modified before that
              time. The <date expression> can be all sorts of date strings  or
              if  it  does not match any internal ones, it is taken as a file-
              name and tries to get the modification date (mtime) from  <file>
              instead.  See  the curl_getdate(3) man pages for date expression
              details.

              Start the date expression with a dash (-) to make it request for
              a  document that is older than the given date/time, default is a
              document that is newer than the specified date/time.

              If this option is used several times, the last one will be used.

              Examples:
               curl -z "Wed 01 Sep 2021 12:18:00" https://example.com
               curl -z "-Wed 01 Sep 2021 12:18:00" https://example.com
               curl -z file https://example.com

       --tls-max <VERSION>
              (SSL) VERSION defines maximum supported TLS version. The minimum
              acceptable version  is  set  by  tlsv1.0,  tlsv1.1,  tlsv1.2  or
              tlsv1.3.

              If  the  connection  is  done  without  TLS,  this option has no
              effect. This includes QUIC-using (HTTP/3) transfers.


              default
                     Use up to recommended TLS version.

              1.0    Use up to TLSv1.0.

              1.1    Use up to TLSv1.1.

              1.2    Use up to TLSv1.2.

              1.3    Use up to TLSv1.3.

       Examples:
        curl --tls-max 1.2 https://example.com
        curl --tls-max 1.3 --tlsv1.2 https://example.com

       See also  --tlsv1.0,  --tlsv1.1,  --tlsv1.2  and  --tlsv1.3.  --tls-max
       requires that the underlying libcurl was built to support TLS. Added in
       7.54.0.

       --tls13-ciphers <ciphersuite list>
              (TLS) Specifies which cipher suites to use in the connection  if
              it  negotiates  TLS 1.3. The list of ciphers suites must specify
              valid ciphers. Read up on TLS 1.3 cipher suite details  on  this
              URL:

               https://curl.se/docs/ssl-ciphers.html

              This  option  is  currently  used only when curl is built to use
              OpenSSL 1.1.1 or later. If you are using a different SSL backend
              you can try setting TLS 1.3 cipher suites by using the --ciphers
              option.

              If this option is used several times, the last one will be used.

              Example:
               curl --tls13-ciphers TLS_AES_128_GCM_SHA256 https://example.com

              Added in 7.61.0.

       --tlsauthtype <type>
              Set  TLS  authentication  type.  Currently,  the  only supported
              option is "SRP",  for  TLS-SRP  (RFC  5054).  If  --tlsuser  and
              --tlspassword  are specified but --tlsauthtype is not, then this
              option defaults to "SRP".  This option works only if the  under-
              lying  libcurl  is  built  with  TLS-SRP support, which requires
              OpenSSL or GnuTLS with TLS-SRP support.

              Example:
               curl --tlsauthtype SRP https://example.com

       --tlspassword <string>
              Set password for use with the TLS authentication  method  speci-
              fied with --tlsauthtype. Requires that --tlsuser also be set.

              This option does not work with TLS 1.3.

              Example:
               curl --tlspassword pwd --tlsuser user https://example.com

       --tlsuser <name>
              Set  username  for use with the TLS authentication method speci-
              fied with --tlsauthtype. Requires  that  --tlspassword  also  is
              set.

              This option does not work with TLS 1.3.

              Example:
               curl --tlspassword pwd --tlsuser user https://example.com

       --tlsv1.0
              (TLS)  Forces curl to use TLS version 1.0 or later when connect-
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_  TLS  1.0, but behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver-
              sion.

              Example:
               curl --tlsv1.0 https://example.com

              Added in 7.34.0.

       --tlsv1.1
              (TLS)  Forces curl to use TLS version 1.1 or later when connect-
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_  TLS  1.1, but behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver-
              sion.

              Example:
               curl --tlsv1.1 https://example.com

              Added in 7.34.0.

       --tlsv1.2
              (TLS)  Forces curl to use TLS version 1.2 or later when connect-
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_  TLS  1.2, but behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver-
              sion.

              Example:
               curl --tlsv1.2 https://example.com

              Added in 7.34.0.

       --tlsv1.3
              (TLS)  Forces curl to use TLS version 1.3 or later when connect-
              ing to a remote TLS server.

              If the connection is  done  without  TLS,  this  option  has  no
              effect. This includes QUIC-using (HTTP/3) transfers.

              Note that TLS 1.3 is not supported by all TLS backends.

              Example:
               curl --tlsv1.3 https://example.com

              Added in 7.52.0.

       -1, --tlsv1
              (SSL)  Tells curl to use at least TLS version 1.x when negotiat-
              ing with a remote TLS server. That  means  TLS  version  1.0  or
              higher

              Example:
               curl --tlsv1 https://example.com

              See  also  --http1.1  and --http2. -1, --tlsv1 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides --tlsv1.1 and --tlsv1.2 and --tlsv1.3.

       --tr-encoding
              (HTTP) Request a compressed Transfer-Encoding response using one
              of the algorithms curl supports, and uncompress the  data  while
              receiving it.

              Example:
               curl --tr-encoding https://example.com

       --trace-ascii <file>
              Enables  a  full  trace  dump of all incoming and outgoing data,
              including descriptive information, to the given output file. Use
              "-" as filename to have the output sent to stdout.

              This is similar to --trace, but leaves out the hex part and only
              shows the ASCII part of the dump. It makes smaller  output  that
              might be easier to read for untrained humans.

              This option is global and does not need to be specified for each
              use of -:, --next.

              If this option is used several times, the last one will be used.

              Example:
               curl --trace-ascii log.txt https://example.com

              This option overrides --trace and -v, --verbose.

       --trace-time
              Prepends  a  time  stamp to each trace or verbose line that curl
              displays.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --trace-time --trace-ascii output https://example.com

       --trace <file>
              Enables  a  full  trace  dump of all incoming and outgoing data,
              including descriptive information, to the given output file. Use
              "-"  as  filename  to have the output sent to stdout. Use "%" as
              filename to have the output sent to stderr.

              This option is global and does not need to be specified for each
              use of -:, --next.

              If this option is used several times, the last one will be used.

              Example:
               curl --trace log.txt https://example.com

              This option overrides -v, --verbose and --trace-ascii.

       --unix-socket <path>
              (HTTP) Connect through this Unix domain socket, instead of using
              the network.

              Example:
               curl --unix-socket socket-path https://example.com

              Added in 7.40.0.

       -T, --upload-file <file>
              This  transfers  the  specified local file to the remote URL. If
              there is no file part in the specified URL, curl will append the
              local file name. NOTE that you must use a trailing / on the last
              directory to really prove to Curl that there is no file name  or
              curl will think that your last directory name is the remote file
              name to use. That will most likely cause the upload operation to
              fail. If this is used on an HTTP(S) server, the PUT command will
              be used.

              Use the file name "-" (a single dash) to use stdin instead of  a
              given  file.   Alternately,  the file name "." (a single period)
              may be specified instead of "-" to  use  stdin  in  non-blocking
              mode  to  allow  reading  server  output  while  stdin  is being
              uploaded.

              You can specify one -T, --upload-file for each URL on  the  com-
              mand  line.  Each -T, --upload-file + URL pair specifies what to
              upload and to where. curl also supports "globbing"  of  the  -T,
              --upload-file  argument,  meaning  that  you can upload multiple
              files to a single URL by using the same URL globbing style  sup-
              ported in the URL.

              When  uploading  to an SMTP server: the uploaded data is assumed
              to be RFC 5322 formatted. It has to feature the necessary set of
              headers  and  mail  body formatted correctly by the user as curl
              will not transcode nor encode it further in any way.

              Examples:
               curl -T file https://example.com
               curl -T "img[1-1000].png" ftp://ftp.example.com/
               curl --upload-file "{file1,file2}" https://example.com

       --url <url>
              Specify a URL to fetch. This option is  mostly  handy  when  you
              want to specify URL(s) in a config file.

              If  the given URL is missing a scheme name (such as "http://" or
              "ftp://" etc) then curl will make a guess based on the host.  If
              the  outermost  sub-domain  name  matches DICT, FTP, IMAP, LDAP,
              POP3 or SMTP then that protocol will  be  used,  otherwise  HTTP
              will be used. Since 7.45.0 guessing can be disabled by setting a
              default protocol, see --proto-default for details.

              This option may be used any number of times.  To  control  where
              this  URL  is written, use the -o, --output or the -O, --remote-
              name options.

              WARNING: On Windows, particular file://  accesses  can  be  con-
              verted to network accesses by the operating system. Beware!

              Example:
               curl --url https://example.com

       -B, --use-ascii
              (FTP  LDAP)  Enable  ASCII  transfer.  For FTP, this can also be
              enforced by using a URL that ends with  ";type=A".  This  option
              causes data sent to stdout to be in text mode for win32 systems.

              Example:
               curl -B ftp://example.com/README

       -A, --user-agent <name>
              (HTTP) Specify the User-Agent string to send to the HTTP server.
              To  encode blanks in the string, surround the string with single
              quote marks. This header can also be set with the  -H,  --header
              or the --proxy-header options.

              If  you give an empty argument to -A, --user-agent (""), it will
              remove the header completely from the request. If you  prefer  a
              blank header, you can set it to a single space (" ").

              If this option is used several times, the last one will be used.

              Example:
               curl -A "Agent 007" https://example.com

       -u, --user <user:password>
              Specify the user name and password to use for server authentica-
              tion. Overrides -n, --netrc and --netrc-optional.

              If  you  simply  specify  the  user name, curl will prompt for a
              password.

              The user name and passwords are split up  on  the  first  colon,
              which  makes  it impossible to use a colon in the user name with
              this option. The password can, still.

              On systems where it works, curl will hide the given option argu-
              ment  from  process listings. This is not enough to protect cre-
              dentials from possibly getting seen by other users on  the  same
              system  as  they  will  still  be  visible  for  a moment before
              cleared. Such sensitive data should be  retrieved  from  a  file
              instead  or  similar  and  never used in clear text in a command
              line.

              When using Kerberos V5 with a Windows based  server  you  should
              include  the  Windows domain name in the user name, in order for
              the server to successfully obtain a Kerberos Ticket. If  you  do
              not, then the initial authentication handshake may fail.

              When  using  NTLM,  the user name can be specified simply as the
              user name, without the domain, if there is a single  domain  and
              forest in your setup for example.

              To  specify  the domain name use either Down-Level Logon Name or
              UPN (User Principal Name) formats. For example, EXAMPLE\user and
              user@example.com respectively.

              If  you  use a Windows SSPI-enabled curl binary and perform Ker-
              beros V5, Negotiate, NTLM or Digest authentication then you  can
              tell  curl  to select the user name and password from your envi-
              ronment by specifying a single colon with this option: "-u :".

              If this option is used several times, the last one will be used.

              Example:
               curl -u user:secret https://example.com

       -v, --verbose
              Makes  curl  verbose  during the operation. Useful for debugging
              and seeing what's going on "under the  hood".  A  line  starting
              with  '>'  means  "header  data" sent by curl, '<' means "header
              data" received by curl that is hidden in  normal  cases,  and  a
              line starting with '*' means additional info provided by curl.

              If you only want HTTP headers in the output, -i, --include might
              be the option you are looking for.

              If you think this option still does not give you enough details,
              consider using --trace or --trace-ascii instead.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Use -s, --silent to make curl really quiet.

              Example:
               curl --verbose https://example.com

              See also  -i,  --include.  This  option  overrides  --trace  and
              --trace-ascii.

       -V, --version
              Displays information about curl and the libcurl version it uses.

              The first line includes the full version of  curl,  libcurl  and
              other 3rd party libraries linked with the executable.

              The  second  line (starts with "Protocols:") shows all protocols
              that libcurl reports to support.

              The third line (starts with "Features:") shows specific features
              libcurl reports to offer. Available features include:

              alt-svc
                     Support for the Alt-Svc: header is provided.

              AsynchDNS
                     This  curl  uses asynchronous name resolves. Asynchronous
                     name resolves can be done using either the c-ares or  the
                     threaded resolver backends.

              brotli Support for automatic brotli compression over HTTP(S).

              CharConv
                     curl was built with support for character set conversions
                     (like EBCDIC)

              Debug  This curl uses a libcurl built with Debug.  This  enables
                     more  error-tracking  and memory debugging etc. For curl-
                     developers only!

              gsasl  The built-in SASL authentication includes  extensions  to
                     support SCRAM because libcurl was built with libgsasl.

              GSS-API
                     GSS-API is supported.

              HSTS   HSTS support is present.

              HTTP2  HTTP/2 support has been built-in.

              HTTP3  HTTP/3 support has been built-in.

              HTTPS-proxy
                     This curl is built to support HTTPS proxy.

              IDN    This curl supports IDN - international domain names.

              IPv6   You can use IPv6 with this.

              Kerberos
                     Kerberos V5 authentication is supported.

              Largefile
                     This curl supports transfers of large files, files larger
                     than 2GB.

              libz   Automatic decompression (via gzip, deflate) of compressed
                     files over HTTP is supported.

              MultiSSL
                     This curl supports multiple TLS backends.

              NTLM   NTLM authentication is supported.

              NTLM_WB
                     NTLM delegation to winbind helper is supported.

              PSL    PSL  is  short for Public Suffix List and means that this
                     curl has been built with  knowledge  about  "public  suf-
                     fixes".

              SPNEGO SPNEGO authentication is supported.

              SSL    SSL  versions of various protocols are supported, such as
                     HTTPS, FTPS, POP3S and so on.

              SSPI   SSPI is supported.

              TLS-SRP
                     SRP (Secure Remote Password) authentication is  supported
                     for TLS.

              TrackMemory
                     Debug memory tracking is supported.

              Unicode
                     Unicode support on Windows.

              UnixSockets
                     Unix sockets support is provided.

              zstd   Automatic  decompression  (via  zstd) of compressed files
                     over HTTP is supported.

       Example:
        curl --version

       -w, --write-out <format>
              Make curl display information on stdout after a completed trans-
              fer.  The  format  is a string that may contain plain text mixed
              with any number of variables. The format can be specified  as  a
              literal  "string",  or  you can have curl read the format from a
              file with "@filename" and to tell curl to read the  format  from
              stdin you write "@-".

              The  variables  present in the output format will be substituted
              by the value or text that curl thinks fit, as  described  below.
              All  variables are specified as %{variable_name} and to output a
              normal % you just write them as %%. You can output a newline  by
              using \n, a carriage return with \r and a tab space with \t.

              The  output  will be written to standard output, but this can be
              switched to standard error by using %{stderr}.

              NOTE: The %-symbol is a special symbol in the win32-environment,
              where  all  occurrences  of  %  must  be doubled when using this
              option.

              The variables available are:

              content_type   The Content-Type of the  requested  document,  if
                             there was any.

              errormsg       The error message. (Added in 7.75.0)

              exitcode       The numerical exitcode of the transfer. (Added in
                             7.75.0)

              filename_effective
                             The ultimate filename that curl  writes  out  to.
                             This  is only meaningful if curl is told to write
                             to a file  with  the  -O,  --remote-name  or  -o,
                             --output  option. It's most useful in combination
                             with the -J, --remote-header-name option.

              ftp_entry_path The initial path curl ended up in when logging on
                             to the remote FTP server.

              http_code      The numerical response code that was found in the
                             last retrieved HTTP(S) or FTP(s) transfer.

              http_connect   The numerical code that was  found  in  the  last
                             response   (from  a  proxy)  to  a  curl  CONNECT
                             request.

              http_version   The  http  version  that  was  effectively  used.
                             (Added in 7.50.0)

              json           A JSON object with all available keys.

              local_ip       The  IP  address  of  the  local  end of the most
                             recently done connection - can be either IPv4  or
                             IPv6.

              local_port     The  local  port number of the most recently done
                             connection.

              method         The http method used  in  the  most  recent  HTTP
                             request. (Added in 7.72.0)

              num_connects   Number  of new connects made in the recent trans-
                             fer.

              num_headers    The number of response headers in the most recent
                             request (restarted at each
                              redirect).  Note  that  the status line IS NOT a
                             header. (Added in 7.73.0)

              num_redirects  Number of redirects that  were  followed  in  the
                             request.

              onerror        The  rest  of  the  output  is  only shown if the
                             transfer returned  a  non-zero  error  (Added  in
                             7.75.0)

              proxy_ssl_verify_result
                             The result of the HTTPS proxy's SSL peer certifi-
                             cate verification that was requested. 0 means the
                             verification was successful. (Added in 7.52.0)

              redirect_url   When an HTTP request was made without -L, --loca-
                             tion to follow redirects (or when --max-redirs is
                             met),  this  variable  will show the actual URL a
                             redirect would have gone to.

              referer        The Referer: header, if there was any. (Added  in
                             7.76.0)

              remote_ip      The  remote  IP address of the most recently done
                             connection - can be either IPv4 or IPv6.

              remote_port    The remote port number of the most recently  done
                             connection.

              response_code  The numerical response code that was found in the
                             last transfer (formerly known as "http_code").

              scheme         The URL scheme (sometimes called  protocol)  that
                             was effectively used. (Added in 7.52.0)

              size_download  The  total  amount of bytes that were downloaded.
                             This is the size of the body/data that was trans-
                             ferred, excluding headers.

              size_header    The total amount of bytes of the downloaded head-
                             ers.

              size_request   The total amount of bytes that were sent  in  the
                             HTTP request.

              size_upload    The  total  amount  of  bytes that were uploaded.
                             This is the size of the body/data that was trans-
                             ferred, excluding headers.

              speed_download The average download speed that curl measured for
                             the complete download. Bytes per second.

              speed_upload   The average upload speed that curl  measured  for
                             the complete upload. Bytes per second.

              ssl_verify_result
                             The  result of the SSL peer certificate verifica-
                             tion that was requested. 0 means the verification
                             was successful.

              stderr         From  this  point  on, the -w, --write-out output
                             will be written  to  standard  error.  (Added  in
                             7.63.0)

              stdout         From  this  point  on, the -w, --write-out output
                             will be written to standard output.  This is  the
                             default,  but  can  be  used to switch back after
                             switching to stderr.  (Added in 7.63.0)

              time_appconnect
                             The time, in seconds,  it  took  from  the  start
                             until  the  SSL/SSH/etc  connect/handshake to the
                             remote host was completed.

              time_connect   The time, in seconds,  it  took  from  the  start
                             until  the  TCP  connect  to  the remote host (or
                             proxy) was completed.

              time_namelookup
                             The time, in seconds,  it  took  from  the  start
                             until the name resolving was completed.

              time_pretransfer
                             The  time,  in  seconds,  it  took from the start
                             until the file transfer was just about to  begin.
                             This includes all pre-transfer commands and nego-
                             tiations that are specific to the particular pro-
                             tocol(s) involved.

              time_redirect  The time, in seconds, it took for all redirection
                             steps including name lookup, connect, pretransfer
                             and  transfer  before  the  final transaction was
                             started. time_redirect shows the complete  execu-
                             tion time for multiple redirections.

              time_starttransfer
                             The  time,  in  seconds,  it  took from the start
                             until the first byte was just about to be  trans-
                             ferred.  This  includes time_pretransfer and also
                             the time  the  server  needed  to  calculate  the
                             result.

              time_total     The  total time, in seconds, that the full opera-
                             tion lasted.

              url            The URL that was fetched. (Added in 7.75.0)

              urlnum         The URL index number of this transfer, 0-indexed.
                             De-globbed  URLs  share  the same index number as
                             the origin globbed URL. (Added in 7.75.0)

              url_effective  The URL that was fetched last. This is most mean-
                             ingful  if you have told curl to follow location:
                             headers.

              If this option is used several times, the last one will be used.

              Example:
               curl -w '%{http_code}\n' https://example.com

       --xattr
              When  saving  output  to a file, this option tells curl to store
              certain file metadata in extended  file  attributes.  Currently,
              the URL is stored in the xdg.origin.url attribute and, for HTTP,
              the content type is stored in the mime_type  attribute.  If  the
              file  system  does not support extended attributes, a warning is
              issued.

              Example:
               curl --xattr -o storage https://example.com


FILES

       ~/.curlrc
              Default config file, see -K, --config for details.


ENVIRONMENT

       The environment variables can be specified in lower case or upper case.
       The lower case version has precedence. http_proxy is an exception as it
       is only available in lower case.

       Using an environment variable to set the proxy has the same  effect  as
       using the -x, --proxy option.


       http_proxy [protocol://]<host>[:port]
              Sets the proxy server to use for HTTP.

       HTTPS_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for HTTPS.

       [url-protocol]_PROXY [protocol://]<host>[:port]
              Sets  the proxy server to use for [url-protocol], where the pro-
              tocol is a protocol that curl supports and  as  specified  in  a
              URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP, etc.

       ALL_PROXY [protocol://]<host>[:port]
              Sets  the  proxy  server to use if no protocol-specific proxy is
              set.

       NO_PROXY <comma-separated list of hosts/domains>
              list of host names that should not go through any proxy. If  set
              to an asterisk '*' only, it matches all hosts. Each name in this
              list is matched as either a domain name which contains the host-
              name, or the hostname itself.

              This  environment  variable  disables use of the proxy even when
              specified   with   the   -x,    --proxy    option.    That    is
              NO_PROXY=direct.example.com   curl  -x  http://proxy.example.com
              http://direct.example.com accesses the target URL directly,  and
              NO_PROXY=direct.example.com   curl  -x  http://proxy.example.com
              http://somewhere.example.com accesses the target URL through the
              proxy.

              The  list  of  host  names  can  also  be  include  numerical IP
              addresses, and  IPv6  versions  should  then  be  given  without
              enclosing brackets.

              IPv6  numerical  addresses are compared as strings, so they will
              only match if the representations are the  same:  "::1"  is  the
              same as "::0:1" but they do not match.

       CURL_SSL_BACKEND <TLS backend>
              If  curl  was built with support for "MultiSSL", meaning that it
              has built-in support for more than one TLS backend,  this  envi-
              ronment  variable can be set to the case insensitive name of the
              particular backend to use when curl is invoked. Setting  a  name
              that  is not a built-in alternative will make curl stay with the
              default.

              SSL backend names (case-insensitive):  bearssl,  gnutls,  gskit,
              mbedtls, mesalink, nss, openssl, rustls, schannel, secure-trans-
              port, wolfssl

       QLOGDIR <directory name>
              If curl was built with HTTP/3 support, setting this  environment
              variable  to  a  local directory will make curl produce qlogs in
              that directory, using file names  named  after  the  destination
              connection  id  (in  hex).  Do  note that these files can become
              rather large. Works with both QUIC backends.

       SSLKEYLOGFILE <file name>
              If you set this environment variable to a file name,  curl  will
              store TLS secrets from its connections in that file when invoked
              to enable you to analyze the TLS traffic in real time using net-
              work analyzing tools such as Wireshark. This works with the fol-
              lowing TLS backends: OpenSSL, libressl, BoringSSL,  GnuTLS,  NSS
              and wolfSSL.


PROXY PROTOCOL PREFIXES

       The  proxy string may be specified with a protocol:// prefix to specify
       alternative proxy protocols.

       If no protocol is specified in the proxy string or if the  string  does
       not  match a supported one, the proxy will be treated as an HTTP proxy.

       The supported proxy protocol prefixes are as follows:

       http://
              Makes it use it as an HTTP proxy. The default if no scheme  pre-
              fix is used.

       https://
              Makes it treated as an HTTPS proxy.

       socks4://
              Makes it the equivalent of --socks4

       socks4a://
              Makes it the equivalent of --socks4a

       socks5://
              Makes it the equivalent of --socks5

       socks5h://
              Makes it the equivalent of --socks5-hostname


EXIT CODES

       There  are  a  bunch  of  different error codes and their corresponding
       error messages that may appear under error conditions. At the  time  of
       this writing, the exit codes are:

       1      Unsupported protocol. This build of curl has no support for this
              protocol.

       2      Failed to initialize.

       3      URL malformed. The syntax was not correct.

       4      A feature or option that  was  needed  to  perform  the  desired
              request  was  not  enabled  or was explicitly disabled at build-
              time. To make curl able to do this, you  probably  need  another
              build of libcurl!

       5      Could  not  resolve  proxy.  The  given  proxy host could not be
              resolved.

       6      Could not resolve host. The  given  remote  host  could  not  be
              resolved.

       7      Failed to connect to host.

       8      Weird server reply. The server sent data curl could not parse.

       9      FTP  access  denied. The server denied login or denied access to
              the particular resource or directory you wanted to  reach.  Most
              often  you tried to change to a directory that does not exist on
              the server.

       10     FTP accept failed. While waiting for the server to connect  back
              when  an active FTP session is used, an error code was sent over
              the control connection or similar.

       11     FTP weird PASS reply. Curl could not parse the reply sent to the
              PASS request.

       12     During  an  active  FTP  session while waiting for the server to
              connect back to curl, the timeout expired.

       13     FTP weird PASV reply, Curl could not parse the reply sent to the
              PASV request.

       14     FTP  weird  227  format.  Curl  could not parse the 227-line the
              server sent.

       15     FTP cannot use host. Could not resolve the host IP we got in the
              227-line.

       16     HTTP/2 error. A problem was detected in the HTTP2 framing layer.
              This is somewhat generic and can be one out of several problems,
              see the error message for details.

       17     FTP  could  not  set binary. Could not change transfer method to
              binary.

       18     Partial file. Only a part of the file was transferred.

       19     FTP could not download/access the given file, the RETR (or simi-
              lar) command failed.

       21     FTP quote error. A quote command returned error from the server.

       22     HTTP page not retrieved. The requested  url  was  not  found  or
              returned  another  error  with  the HTTP error code being 400 or
              above. This return code only appears if -f, --fail is used.

       23     Write error. Curl could not write data to a local filesystem  or
              similar.

       25     FTP  could  not STOR file. The server denied the STOR operation,
              used for FTP uploading.

       26     Read error. Various reading problems.

       27     Out of memory. A memory allocation request failed.

       28     Operation timeout. The specified  time-out  period  was  reached
              according to the conditions.

       30     FTP  PORT  failed.  The PORT command failed. Not all FTP servers
              support the PORT  command,  try  doing  a  transfer  using  PASV
              instead!

       31     FTP could not use REST. The REST command failed. This command is
              used for resumed FTP transfers.

       33     HTTP range error. The range "command" did not work.

       34     HTTP post error. Internal post-request generation error.

       35     SSL connect error. The SSL handshaking failed.

       36     Bad download resume. Could not continue an earlier aborted down-
              load.

       37     FILE  could not read file. Failed to open the file. Permissions?

       38     LDAP cannot bind. LDAP bind operation failed.

       39     LDAP search failed.

       41     Function not found. A required LDAP function was not found.

       42     Aborted by callback. An application told curl to abort the oper-
              ation.

       43     Internal error. A function was called with a bad parameter.

       45     Interface  error.  A  specified  outgoing interface could not be
              used.

       47     Too many redirects. When following redirects, curl hit the maxi-
              mum amount.

       48     Unknown  option  specified  to  libcurl. This indicates that you
              passed a weird option to curl that was passed on to libcurl  and
              rejected. Read up in the manual!

       49     Malformed telnet option.

       51     The peer's SSL certificate or SSH MD5 fingerprint was not OK.

       52     The  server  did not reply anything, which here is considered an
              error.

       53     SSL crypto engine not found.

       54     Cannot set SSL crypto engine as default.

       55     Failed sending network data.

       56     Failure in receiving network data.

       58     Problem with the local certificate.

       59     Could not use specified SSL cipher.

       60     Peer certificate cannot be authenticated with known CA  certifi-
              cates.

       61     Unrecognized transfer encoding.

       62     Invalid LDAP URL.

       63     Maximum file size exceeded.

       64     Requested FTP SSL level failed.

       65     Sending the data requires a rewind that failed.

       66     Failed to initialise SSL Engine.

       67     The  user  name,  password, or similar was not accepted and curl
              failed to log in.

       68     File not found on TFTP server.

       69     Permission problem on TFTP server.

       70     Out of disk space on TFTP server.

       71     Illegal TFTP operation.

       72     Unknown TFTP transfer ID.

       73     File already exists (TFTP).

       74     No such user (TFTP).

       75     Character conversion failed.

       76     Character conversion functions required.

       77     Problem reading the SSL CA cert (path? access rights?).

       78     The resource referenced in the URL does not exist.

       79     An unspecified error occurred during the SSH session.

       80     Failed to shut down the SSL connection.

       82     Could not load CRL file, missing or wrong format.

       83     Issuer check failed.

       84     The FTP PRET command failed.

       85     Mismatch of RTSP CSeq numbers.

       86     Mismatch of RTSP Session Identifiers.

       87     Unable to parse FTP file list.

       88     FTP chunk callback reported error.

       89     No connection available, the session will be queued.

       90     SSL public key does not matched pinned public key.

       91     Invalid SSL certificate status.

       92     Stream error in HTTP/2 framing layer.

       93     An API function was called from inside a callback.

       94     An authentication function returned an error.

       95     A problem was detected in the HTTP/3  layer.  This  is  somewhat
              generic  and  can  be one out of several problems, see the error
              message for details.

       96     QUIC connection error. This  error  may  be  caused  by  an  SSL
              library error. QUIC is the protocol used for HTTP/3 transfers.

       XX     More error codes will appear here in future releases. The exist-
              ing ones are meant to never change.


AUTHORS / CONTRIBUTORS

       Daniel Stenberg is the main author, but the whole list of  contributors
       is found in the separate THANKS file.


WWW

       https://curl.se


SEE ALSO

       ftp(1), wget(1)



curl 7.80.0                    November 10 2021                        curl(1)

curl 7.80.0 - Generated Sat Nov 20 18:08:08 CST 2021
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