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tset(1)                                                                tset(1)




NAME

       tset, reset - terminal initialization


SYNOPSIS

       tset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal]
       reset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal]


DESCRIPTION

       Tset initializes terminals.  Tset first determines the type of terminal
       that you are using.  This determination is done as follows,  using  the
       first terminal type found.

       1. The terminal argument specified on the command line.

       2. The value of the TERM environmental variable.

       3.  (BSD  systems only.) The terminal type associated with the standard
       error output device in the /etc/ttys file.   (On  System-V-like  UNIXes
       and  systems using that convention, getty does this job by setting TERM
       according to the type passed to it by /etc/inittab.)

       4. The default terminal type, ``unknown''.

       If the terminal type was not specified  on  the  command-line,  the  -m
       option mappings are then applied (see the section TERMINAL TYPE MAPPING
       for more information).  Then, if the terminal type begins with a  ques-
       tion  mark (``?''), the user is prompted for confirmation of the termi-
       nal type.  An empty response confirms the type, or, another type can be
       entered  to specify a new type.  Once the terminal type has been deter-
       mined, the terminfo entry for the terminal is retrieved.   If  no  ter-
       minfo  entry  is  found  for the type, the user is prompted for another
       terminal type.

       Once the terminfo entry  is  retrieved,  the  window  size,  backspace,
       interrupt  and  line  kill characters (among many other things) are set
       and the terminal and tab initialization strings are sent to  the  stan-
       dard  error  output.   Finally,  if  the erase, interrupt and line kill
       characters have changed, or are not set to their default values,  their
       values  are  displayed  to the standard error output.  Use the -c or -w
       option to select only the window sizing versus  the  other  initializa-
       tion.  If neither option is given, both are assumed.

       When  invoked  as  reset,  tset  sets  cooked and echo modes, turns off
       cbreak and raw modes, turns on newline translation and resets any unset
       special  characters  to  their default values before doing the terminal
       initialization described above.  This is useful after  a  program  dies
       leaving a terminal in an abnormal state.  Note, you may have to type

           <LF>reset<LF>

       (the  line-feed character is normally control-J) to get the terminal to
       work, as carriage-return may no longer  work  in  the  abnormal  state.
       Also, the terminal will often not echo the command.

       The options are as follows:

       -c   Set  control  characters and modes.  -e Set the erase character to
            ch.

       -I   Do not send the terminal or tab initialization strings to the ter-
            minal.

       -i   Set the interrupt character to ch.

       -k   Set the line kill character to ch.

       -m   Specify a mapping from a port type to a terminal.  See the section
            TERMINAL TYPE MAPPING for more information.

       -Q   Do not display any values for the erase, interrupt and  line  kill
            characters.  Normally tset displays the values for control charac-
            ters which differ from the system's default values.

       -q   The terminal type is displayed to the  standard  output,  and  the
            terminal  is not initialized in any way.  The option `-' by itself
            is equivalent but archaic.

       -r   Print the terminal type to the standard error output.

       -s   Print the sequence of shell commands to initialize the environment
            variable TERM to the standard output.  See the section SETTING THE
            ENVIRONMENT for details.

       -V   reports the version of ncurses which was used in this program, and
            exits.

       -w   Resize  the  window to match the size deduced via setupterm.  Nor-
            mally this has no effect, unless setupterm is not able  to  detect
            the window size.

       The  arguments  for the -e, -i, and -k options may either be entered as
       actual characters or by using the `hat' notation, i.e.,  control-h  may
       be specified as ``^H'' or ``^h''.


SETTING THE ENVIRONMENT

       It  is often desirable to enter the terminal type and information about
       the terminal's capabilities into the shell's environment.  This is done
       using the -s option.

       When  the -s option is specified, the commands to enter the information
       into the shell's environment are written to the  standard  output.   If
       the  SHELL environmental variable ends in ``csh'', the commands are for
       csh, otherwise, they are for sh.  Note, the csh commands set and  unset
       the shell variable noglob, leaving it unset.  The following line in the
       .login or .profile files will initialize the environment correctly:

           eval `tset -s options ... `


TERMINAL TYPE MAPPING

       When the terminal is not hardwired into the system (or the current sys-
       tem  information  is  incorrect)  the  terminal  type  derived from the
       /etc/ttys file or the TERM environmental variable  is  often  something
       generic  like  network,  dialup,  or  unknown.   When tset is used in a
       startup script it is often desirable to provide information  about  the
       type of terminal used on such ports.

       The purpose of the -m option is to map from some set of conditions to a
       terminal type, that is, to tell tset ``If I'm on this port at a partic-
       ular speed, guess that I'm on that kind of terminal''.

       The  argument  to  the  -m option consists of an optional port type, an
       optional operator, an optional baud  rate  specification,  an  optional
       colon (``:'') character and a terminal type.  The port type is a string
       (delimited by either the operator or the colon character).  The  opera-
       tor  may  be  any  combination of ``>'', ``<'', ``@'', and ``!''; ``>''
       means greater than, ``<'' means less than, ``@''  means  equal  to  and
       ``!''  inverts  the sense of the test.  The baud rate is specified as a
       number and is compared with the speed  of  the  standard  error  output
       (which should be the control terminal).  The terminal type is a string.

       If the terminal type is not specified on the command line, the -m  map-
       pings are applied to the terminal type.  If the port type and baud rate
       match the mapping, the terminal type specified in the mapping  replaces
       the  current  type.   If  more than one mapping is specified, the first
       applicable mapping is used.

       For example, consider the following  mapping:  dialup>9600:vt100.   The
       port type is dialup , the operator is >, the baud rate specification is
       9600, and the terminal type is vt100.  The result of this mapping is to
       specify  that  if  the  terminal  type  is dialup, and the baud rate is
       greater than 9600 baud, a terminal type of vt100 will be used.

       If no baud rate is specified, the terminal type  will  match  any  baud
       rate.   If  no port type is specified, the terminal type will match any
       port type.  For example, -m dialup:vt100  -m  :?xterm  will  cause  any
       dialup port, regardless of baud rate, to match the terminal type vt100,
       and any non-dialup port type to match the terminal type ?xterm.   Note,
       because  of  the  leading  question mark, the user will be queried on a
       default port as to whether they are actually using an xterm terminal.

       No whitespace characters are  permitted  in  the  -m  option  argument.
       Also,  to avoid problems with meta-characters, it is suggested that the
       entire -m option argument be placed within single quote characters, and
       that csh users insert a backslash character (``\'') before any exclama-
       tion marks (``!'').


HISTORY

       The tset command appeared in BSD 3.0.  The ncurses  implementation  was
       lightly  adapted  from the 4.4BSD sources for a terminfo environment by
       Eric S. Raymond <esr@snark.thyrsus.com>.


COMPATIBILITY

       The tset utility has been provided for backward-compatibility with  BSD
       environments  (under  most modern UNIXes, /etc/inittab and getty(1) can
       set TERM appropriately for each dial-up line; this  obviates  what  was
       tset's  most  important  use).  This implementation behaves like 4.4BSD
       tset, with a few exceptions specified here.

       The -S option of BSD tset no longer works; it prints an  error  message
       to  stderr  and dies.  The -s option only sets TERM, not TERMCAP.  Both
       these changes are because the TERMCAP variable is no  longer  supported
       under  terminfo-based  ncurses, which makes tset -S useless (we made it
       die noisily rather than silently induce lossage).

       There was an undocumented 4.4BSD feature that invoking tset via a  link
       named  `TSET`  (or via any other name beginning with an upper-case let-
       ter) set the terminal to use upper-case only.  This  feature  has  been
       omitted.

       The -A, -E, -h, -u and -v options were deleted from the tset utility in
       4.4BSD.  None of them were documented in 4.3BSD and all are of  limited
       utility  at  best.   The -a, -d, and -p options are similarly not docu-
       mented or useful, but were retained as they appear to be in  widespread
       use.   It is strongly recommended that any usage of these three options
       be changed to use the -m option instead.  The -n  option  remains,  but
       has  no effect.  The -adnp options are therefore omitted from the usage
       summary above.

       It is still permissible to specify the -e, -i, and -k  options  without
       arguments, although it is strongly recommended that such usage be fixed
       to explicitly specify the character.

       As of 4.4BSD, executing tset as reset no longer implies the -Q  option.
       Also, the interaction between the - option and the terminal argument in
       some historic implementations of tset has been removed.


ENVIRONMENT

       The tset command uses these environment variables:

       SHELL
            tells tset whether to initialize TERM using sh or csh syntax.

       TERM Denotes your terminal  type.   Each  terminal  type  is  distinct,
            though many are similar.

       TERMCAP
            may  denote  the  location of a termcap database.  If it is not an
            absolute pathname, e.g., begins with a `/', tset removes the vari-
            able from the environment before looking for the terminal descrip-
            tion.


FILES

       /etc/ttys
            system port name to terminal type mapping database  (BSD  versions
            only).

       /usr/local/share/terminfo
            terminal capability database


SEE ALSO

       csh(1),   sh(1),   stty(1),   curs_terminfo(3X),  tty(4),  terminfo(5),
       ttys(5), environ(7)

       This describes ncurses version 5.8 (patch 20110226).



                                                                       tset(1)

ncurses 5.8 - Generated Sun Feb 27 05:18:35 CST 2011