


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



NAME
     tset - terminal dependent initialization

SYNOPSIS
     tset [ options ] [ -m [ident][test baudrate]:type ] ... [
     type ]

     reset [ options ] [ -m [ident][test baudrate]:type ] ... [
     type ]

DESCRIPTION
     _T_s_e_t sets up your terminal when you first log in to a UNIX
     system.  It does terminal dependent processing such as set-
     ting erase and kill characters, setting or resetting delays,
     sending any sequences needed to properly initialized the
     terminal, and the like.  It first determines the _t_y_p_e of
     terminal involved, and then does necessary initializations
     and mode settings.  The type of terminal attached to each
     UNIX port is specified in the /_e_t_c/_t_t_y_s(5) database.  Type
     names for terminals may be found in the _t_e_r_m_c_a_p(5) database.
     If a port is not wired permanently to a specific terminal
     (not hardwired) it will be given an appropriate generic
     identifier such as _d_i_a_l_u_p.

     In the case where no arguments are specified, _t_s_e_t simply
     reads the terminal type out of the environment variable TERM
     and re-initializes the terminal.  The rest of this manual
     concerns itself with mode and environment initialization,
     typically done once at login, and options used at initiali-
     zation time to determine the terminal type and set up termi-
     nal modes.

     When used in a startup script (._p_r_o_f_i_l_e for _s_h(1) users or
     ._l_o_g_i_n for _c_s_h(1) users) it is desirable to give information
     about the type of terminal you will usually use on ports
     which are not hardwired.  These ports are identified in
     /_e_t_c/_t_t_y_s as _d_i_a_l_u_p or _p_l_u_g_b_o_a_r_d or _a_r_p_a_n_e_t, etc.	To
     specify what terminal type you usually use on these ports,
     the -m (map) option flag is followed by the appropriate port
     type identifier, an optional baud rate specification, and
     the terminal type.  (The effect is to ``map'' from some con-
     ditions to a terminal type, that is, to tell _t_s_e_t ``If I'm
     on this kind of port, guess that I'm on that kind of termi-
     nal''.) If more than one mapping is specified, the first
     applicable mapping prevails.  A missing port type identifier
     matches all identifiers.  Any of the alternate generic names
     given in _t_e_r_m_c_a_p may be used for the identifier.

     A _b_a_u_d_r_a_t_e is specified as with _s_t_t_y(1), and is compared
     with the speed of the diagnostic output (which should be the
     control terminal).  The baud rate _t_e_s_t may be any combina-
     tion of: >, @, <, and !; @ means ``at'' and ! inverts the



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



     sense of the test.  To avoid problems with metacharacters,
     it is best to place the entire argument to -m within ``'''
     characters; users of _c_s_h(1) must also put a ``\'' before any
     ``!'' used here.

     Thus

	  tset -m 'dialup>300:adm3a' -m dialup:dw2 -m
	  'plugboard:?adm3a'

     causes the terminal type to be set to an _a_d_m_3_a if the port
     in use is a dialup at a speed greater than 300 baud; to a
     _d_w_2 if the port is (otherwise) a dialup (i.e. at 300 baud or
     less).  (NOTE: the examples given here appear to take up
     more than one line, for text processing reasons.  When you
     type in real _t_s_e_t commands, you must enter them entirely on
     one line.) If the _t_y_p_e finally determined by _t_s_e_t begins
     with a question mark, the user is asked if s/he really wants
     that type.  A null response means to use that type; other-
     wise, another type can be entered which will be used
     instead.  Thus, in the above case, the user will be queried
     on a plugboard port as to whether they are actually using an
     _a_d_m_3_a.

     If no mapping applies and a final _t_y_p_e option, not preceded
     by a -m, is given on the command line then that type is
     used; otherwise the type found in the /_e_t_c/_t_t_y_s database
     will be taken to be the terminal type.  This should always
     be the case for hardwired ports.

     It is usually desirable to return the terminal type, as
     finally determined by _t_s_e_t, and information about the
     terminal's capabilities to a shell's environment.	This can
     be done using the - option; using the Bourne shell, _s_h(1):

	  export TERM; TERM=`tset - _o_p_t_i_o_n_s...`

     or using the C shell, _c_s_h(1):

	  setenv TERM `tset - _o_p_t_i_o_n_s...`

     With _c_s_h it is preferable to use the following command in
     your .login file to initialize the TERM and TERMCAP environ-
     ment variables at the same time.

	  eval `tset -s _o_p_t_i_o_n_s...`

     It is also convenient to make an alias in your .cshrc:

	  alias tset 'eval `tset -s \!*`'





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



     This allows the command:

	  tset 2621

     to be invoked at any time to set the terminal and environ-
     ment.  Note to Bourne Shell users: It is not possible to get
     this aliasing effect with a shell script, because shell
     scripts cannot set the environment of their parent.  (If a
     process could set its parent's environment, none of this
     nonsense would be necessary in the first place.)

     These commands cause _t_s_e_t to place the name of your terminal
     in the variable TERM in the environment; see _e_n_v_i_r_o_n(7).

     Once the terminal type is known, _t_s_e_t engages in terminal
     driver mode setting.  This normally involves sending an ini-
     tialization sequence to the terminal, setting the single
     character erase (and optionally the line-kill (full line
     erase)) characters, and setting special character delays.
     Tab and newline expansion are turned off during transmission
     of the terminal initialization sequence.

     On terminals that can backspace but not overstrike (such as
     a CRT), and when the erase character is the default erase
     character (`#' on standard systems), the erase character is
     changed to BACKSPACE (Control-H).

     The options are:

     -e_c  set the erase character to be the named character _c on
	  all terminals, the default being the backspace charac-
	  ter on the terminal, usually ^H.  The character _c can
	  either be typed directly, or entered using the hat
	  notation used here.

     -k_c  is similar to -e but for the line kill character rather
	  than the erase character; _c defaults to ^X (for purely
	  historical reasons).	The kill characters is left alone
	  if -k is not specified.  The hat notation can also be
	  used for this option.

     -i_c  is similar to -e but for the interrupt character rather
	  than the erase character; _c defaults to ^C.  The hat
	  notation can also be used for this option.

     -	  The name of the terminal finally decided upon is output
	  on the standard output.  This is intended to be cap-
	  tured by the shell and placed in the environment vari-
	  able TERM.

     -s   Print the sequence of _c_s_h commands to initialize the
	  environment variables TERM and TERMCAP based on the



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



	  name of the terminal finally decided upon.

     -n   On systems with the Berkeley 4BSD tty driver, specifies
	  that the new tty driver modes should be initialized for
	  this terminal.  For a CRT, the CRTERASE and CRTKILL
	  modes are set only if the baud rate is 1200 or greater.
	  See tty(4) for more detail.

     -I   suppresses transmitting terminal initialization
	  strings.

     -Q   suppresses printing the ``Erase set to'' and ``Kill set
	  to'' messages.

     If tset is invoked as reset, it will set cooked and echo
     modes, turn off cbreak and raw modes, turn on newline trans-
     lation, and restore special characters to a sensible state
     before any terminal dependent processing is done.	Any spe-
     cial character that is found to be NULL or ``-1'' is reset
     to its default value.  All arguments to _t_s_e_t may be used
     with reset.

     This is most useful after a program dies leaving a terminal
     in a funny state. You may have to type ``<LF>reset<LF>'' to
     get it to work since <CR> may not work in this state. Often
     none of this will echo.

EXAMPLES
     These examples all assume the Bourne shell and use the -
     option.  If you use _c_s_h, use one of the variations described
     above.  Note that a typical use of _t_s_e_t in a .profile or
     .login will also use the -e and -k options, and often the -n
     or -Q options as well.  These options have not been included
     here to keep the examples small.  (NOTE: some of the exam-
     ples given here appear to take up more than one line, for
     text processing reasons.  When you type in real _t_s_e_t com-
     mands, you must enter them entirely on one line.)

     At the moment, you are on a 2621.	This is suitable for typ-
     ing by hand but not for a .profile, unless you are _a_l_w_a_y_s on
     a 2621.

	  export TERM; TERM=`tset - 2621`

     You have an h19 at home which you dial up on, but your
     office terminal is hardwired and known in /etc/ttys.

	  export TERM; TERM=`tset - -m dialup:h19`

     You have a switch which connects everything to everything,
     making it nearly impossible to key on what port you are com-
     ing in on.  You use a vt100 in your office at 9600 baud, and



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



     dial up to switch ports at 1200 baud from home on a 2621.
     Sometimes you use someone elses terminal at work, so you
     want it to ask you to make sure what terminal type you have
     at high speeds, but at 1200 baud you are always on a 2621.
     Note the placement of the question mark, and the quotes to
     protect the greater than and question mark from interpreta-
     tion by the shell.

	  export TERM; TERM=`tset - -m 'switch>1200:?vt100' -m
	  'switch<=1200:2621'

     All of the above entries will fall back on the terminal type
     specified in /_e_t_c/_t_t_y_s if none of the conditions hold.  The
     following entry is appropriate if you always dial up, always
     at the same baud rate, on many different kinds of terminals.
     Your most common terminal is an adm3a.  It always asks you
     what kind of terminal you are on, defaulting to adm3a.

	  export TERM; TERM=`tset - ?adm3a`

     If the file /_e_t_c/_t_t_y_s is not properly installed and you want
     to key entirely on the baud rate, the following can be used:

	  export TERM; TERM=`tset - -m '>1200:vt100' 2621`

     Here is a fancy example to illustrate the power of _t_s_e_t and
     to hopelessly confuse anyone who has made it this far.  You
     dial up at 1200 baud or less on a concept100, sometimes over
     switch ports and sometimes over regular dialups.  You use
     various terminals at speeds higher than 1200 over switch
     ports, most often the terminal in your office, which is a
     vt100.  However, sometimes you log in from the university
     you used to go to, over the ARPANET; in this case you are on
     an ALTO emulating a dm2500.  You also often log in on vari-
     ous hardwired ports, such as the console, all of which are
     properly entered in /_e_t_c/_t_t_y_s.  You want your erase charac-
     ter set to control H, your kill character set to control U,
     and don't want _t_s_e_t to print the ``Erase set to Backspace,
     Kill set to Control U'' message.

	  export TERM; TERM=`tset -e -k^U -Q - -m
	  'switch<=1200:concept100' -m 'switch:?vt100' -m
	  dialup:concept100 -m arpanet:dm2500`

FILES
     /etc/ttys port name to terminal type mapping database
     /etc/termcap   terminal capability database

SEE ALSO
     csh(1), sh(1), stty(1), ttys(5), termcap(5), environ(7)





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



BUGS
     The _t_s_e_t command is one of the first commands a user must
     master when getting started on a UNIX system.  Unfor-
     tunately, it is one of the most complex, largely because of
     the extra effort the user must go through to get the
     environment of the login shell set.  Something needs to be
     done to make all this simpler, either the _l_o_g_i_n(1) program
     should do this stuff, or a default shell alias should be
     made, or a way to set the environment of the parent should
     exist.

     This program can't intuit personal choices for erase, inter-
     rupt and line kill characters, so it leaves these set to the
     local system standards.

NOTES
     For compatibility with earlier versions of _t_s_e_t a number of
     flags are accepted whose use is discouraged:

     -d type   equivalent to -m dialup:type

     -p type   equivalent to -m plugboard:type

     -a type   equivalent to -m arpanet:type

     -	       prints the terminal type on the standard output

     -r        prints the terminal type on the diagnostic output.



























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