manpagez: man pages & more
man shred(1)
Home | html | info | man
shred(1)                         User Commands                        shred(1)


       shred - overwrite a file to hide its contents, and optionally delete it


       shred [OPTION]... FILE...


       Overwrite the specified FILE(s) repeatedly, in order to make it  harder
       for even very expensive hardware probing to recover the data.

       If FILE is -, shred standard output.

       Mandatory  arguments  to  long  options are mandatory for short options

       -f, --force
              change permissions to allow writing if necessary

       -n, --iterations=N
              overwrite N times instead of the default (3)

              get random bytes from FILE

       -s, --size=N
              shred this many bytes (suffixes like K, M, G accepted)

       -u     deallocate and remove file after overwriting

              like -u but give control on HOW to delete;  See below

       -v, --verbose
              show progress

       -x, --exact
              do not round file sizes up to the next full block;

              this is the default for non-regular files

       -z, --zero
              add a final overwrite with zeros to hide shredding

       --help display this help and exit

              output version information and exit

       Delete FILE(s) if --remove (-u) is specified.  The default  is  not  to
       remove  the  files because it is common to operate on device files like
       /dev/hda, and those files usually should not be removed.  The  optional
       HOW  parameter  indicates  how to remove a directory entry: 'unlink' =>
       use a standard unlink call.  'wipe' => also first  obfuscate  bytes  in
       the  name.   'wipesync' => also sync each obfuscated byte to disk.  The
       default mode is 'wipesync', but note it can be expensive.

       CAUTION: shred assumes the file system and hardware overwrite  data  in
       place.   Although  this  is  common,  many platforms operate otherwise.
       Also, backups and mirrors may contain unremovable copies that will  let
       a  shredded  file be recovered later.  See the GNU coreutils manual for


       Written by Colin Plumb.


       GNU coreutils online help: <>
       Report any translation bugs to <>


       Copyright (C) 2020 Free Software Foundation, Inc.  License GPLv3+:  GNU
       GPL version 3 or later <>.
       This  is  free  software:  you  are free to change and redistribute it.
       There is NO WARRANTY, to the extent permitted by law.


       Full documentation <>
       or available locally via: info '(coreutils) shred invocation'

GNU coreutils 8.32                March 2020                          shred(1)

coreutils 8.32 - Generated Sat Mar 7 09:02:51 CST 2020
© 2000-2022
Individual documents may contain additional copyright information.