tset(1)			    General Commands Manual		       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 Linux and System-V-like
       UNIXes,	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/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 5.7 (patch 20090207).



								       tset(1)