MirOS Manual: reset(1), tset(1)


tset(1)             UNIX Programmer's 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 set-
     ting 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, back-
     space, 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
     values before doing the terminal initialization described

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     above.  This is useful after a program dies leaving a termi-
     nal 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 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 characters 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 setup-
          term. 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''.

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tset(1)             UNIX Programmer's Manual              tset(1)

SETTING THE ENVIRONMENT

     It is often desirable to enter the terminal type and infor-
     mation 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 vari-
     able 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 con-
     ditions 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 specifica-
     tion, 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 termi-
     nal). 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 applicable mapping
     is used.

     For example, consider the following mapping:
     dialup>9600:vt100. The port type is dialup , the operator is

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     >, 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 implemen-
     tation 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

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     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), setupterm(3), tty(4), termcap(5),
     ttys(5), environ(7)

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