Provided by: ncurses-bin_5.7+20090803-2ubuntu2_i386 bug

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
       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 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
            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 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 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  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 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
       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 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
            variable  from  the  environment  before  looking for the terminal
            description.

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),   curs_terminfo(3X),  tty(4),  terminfo(5),
       ttys(5), environ(7)

       This describes ncurses version 5.7 (patch 20090803).

                                                                       tset(1)