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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 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

	   reset

       (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 systems 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 terminals capabilities into the shells environment.	This is done
       using the -s option.

       When  the -s option is specified, the commands to enter the information
       into the shells 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 Im on this port at a partic
       ular speed, guess that Im 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 .

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
       tsets  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 the SHELL and TERM environment variables.

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

       /etc/terminfo
	    terminal capability database

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



								       tset(1)




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