NAME

       tset, reset - terminal initialization


SYNOPSIS

       tset  [-IQVqrs]  [-]  [-e ch] [-i ch] [-k ch] [-m mapping]
       [terminal]
       reset [-IQVqrs] [-] [-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  below
       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 con-
       firms 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 initializa-
       tion  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.

       When invoked as reset, tset sets cooked  and  echo  modes,
       turns  off cbreak and raw modes, turns on newline transla-
       tion 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:

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

       -e   Set the erase character to ch.

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

       -Q   Don't display any values for the erase, interrupt and
            line kill characters.

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

       -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 below for more information.

       -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 below on setting the environment  for
            details.

       The arguments for the -e, -i, and -k options may either be
       entered as actual characters or by using the  `hat'  nota-
       tion, 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
       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 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 specifi-
       cation, 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 specified, the first  applica-
       ble 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 termi-
       nal type is vt100.  The result of this mapping is to spec-
       ify 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  imple-
       mentation  was lightly adapted from the 4.4BSD sources for
       a terminfo environment by Eric S. Raymond <esr@snark.thyr-
       sus.com>.


COMPATIBILITY

       The  tset  utility has been provided for backward-compati-
       bility 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 begin-
       ning  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 recom-
       mended 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 vari-
       ables.


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), tty(4), termcap(5), ttys(5), envi-
       ron(7)








































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