RESET linux command manual

tset(1)                                                                     tset(1)

       tset, reset - terminal initialization

       tset [-IQVqrs] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal]
       reset [-IQVqrs] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal]

       Tset  initializes terminals.  Tset first determines the type of termi-
       nal 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 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 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.

       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 ter-
       minal  initialization described above.  This is useful after a program
       dies leaving a terminal in an abnormal state.  Note, you may  have  to


       (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 output, 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

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

       -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 environ-
            ment 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' notation, i.e.  control-h  may
       be specified as ''^H'' or ''^h''.

       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  cor-

           eval `tset -s options ... `

       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 par-
       ticular 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 out-
       put (which should be the control terminal).  The terminal  type  is  a

       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 ter-

       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 (''!'').

       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 .

       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 let-
       ter) set the terminal to use upper-case only.  This feature  has  been

       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 lim-
       ited     utility     at     best.      The     -a,     -,     and    -
       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.

       The tset command uses the SHELL and TERM environment variables.

            system port name to terminal type mapping database (BSD  versions

            terminal capability database

       csh(1), sh(1), stty(1), tty(4), termcap(5), ttys(5), environ(7)