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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 question mark (``?''), the user is prompted	for  confirmation
       of  the	terminal  type.   An  empty  response  confirms the type, or, another type can be
       entered to specify a new type.  Once the terminal type has been determined,  the  terminfo
       entry for the terminal is retrieved.  If no terminfo 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 standard 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 initialization.	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 val-
       ues before doing the terminal initialization described above.  This is useful after a pro-
       gram 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 terminal.

       -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 MAP-
	    PING for more information.

       -Q   Do	not  display  any values for the erase, interrupt and line kill characters.  Nor-
	    mally tset displays the values for control characters which differ from the  system's
	    default values.

       -q   The  terminal  type is displayed to the standard output, and the terminal is not ini-
	    tialized 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.  Normally 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 system  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 termi-
       nal 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 particular 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
       operator  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 mappings 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  speci-
       fied, 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 exclamation 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 letter) 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 documented 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 interac-
       tion 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 variable from the environment before  look-
	    ing for the terminal description.

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 5.9 (patch 20110404).

											  tset(1)
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