tset - terminal dependent initialization
tset [ options ]
Tset causes terminal dependent processing such as setting erase and kill
characters, setting or resetting delays, and the like. It first
determines the type of terminal involved, names for which are specified
by the /usr/lib/terminfo data base, and then does necessary
initializations and mode settings. In the case where no argument types
are specified, tset simply reads the terminal type out of the environment
variable TERM and re-initializes the terminal. The rest of this manual
concerns itself with type initialization, done typically once at login,
and options used at initialization time to determine the terminal type
and set up terminal modes.
When used in a startup script ".profile" (for sh(1) users) or ".login"
(for csh(1) users), it is desirable to give information about the types
of terminal usually used, for terminals which are connected to the
computer through a modem. These ports are initially identified as being
dialup or plugboard or arpanet etc. To specify what terminal type is
usually used on these ports, -m is followed by the appropriate port type
identifier, an optional baud-rate specification, and the terminal type to
be used if the mapping conditions are satisfied. If more than one
mapping is specified, the first applicable mapping prevails. A missing
type identifier matches all identifiers.
Baud rates are specified as with stty(1), and are compared with the speed
of the diagnostic output (which is almost always the control terminal).
The baud rate test may be any combination of: >, =, <, @, and !; @ is a
synonym for = and ! inverts the sense of the test. To avoid problems
with metacharacters, it is best to place the entire argument to -m within
'' characters; users of csh(1) must also put a "\" before any "!" used
tset -m 'dialup>300:adm3a' -m dialup:dw2
causes the terminal type to be set to an adm3a if the port in use is a
dialup at a speed greater than 300 baud; to a dw2 if the port is
(otherwise) a dialup (i.e., at 300 baud or less). If the type above
begins with a question mark, the user is asked if the user really wants
that type. A null response means to use that type; otherwise, another
type can be entered which will be used instead. For other ports the port
type will be taken from the /etc/ttytype file or a final, default type
option may be given on the command line not preceded by a -m. A ttytype
may be preceded with a question mark in /etc/ttytype for prompting (this
is an enhancement over standard tset).
It is often desirable to return the terminal type, as specified by the -m
options, and information about the terminal to a shell's environment.
This can be done using the -s option; using the Bourne shell, sh(1):
eval `tset -s options ... `
or using the C shell, csh(1):
tset -s options ... > tset$$
These commands cause tset to generate as output a sequence of shell
commands which place the variable TERM in the environment; see
Once the terminal type is known, tset engages in terminal mode setting.
This normally involves sending an initialization sequence to the terminal
and setting the single character erase (and optionally the line-kill
(full line erase)) characters.
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 a ^H (backspace).
Other options are:
-e set the erase character to be the named character c on all terminals,
the default being the backspace character on the terminal, usually
-k is similar to -e but for the line kill character rather than the
erase character; c defaults to ^X (for purely historical reasons); ^U
is the preferred setting. No kill processing is done if -k is not
-h do not read the terminal type from the environment variable TERM.
-I suppresses outputting terminal initialization strings.
-Q suppresses printing the ``Erase set to'' and ``Kill set to''
-S Outputs just the strings to be assigned to TERM rather than commands
for a shell.
A typical csh ".login" file using tset would be:
set tmp = `tset - -m dialup:?h19 -Q`
setenv TERM "$tmp"
unset tmp noglob
This ".login" sets the environment variable TERM for the user's current
terminal according to the file /etc/ttytype . If the terminal line is a
dialup line, the user is prompted for the proper terminal type.
tset determines which set of commands to use (setenv vs export) by
looking at the SHELL environment variable when the -s option is given.
This is not a problem at login, but for testing shell's other than one's
normal shell, it may be necessary to change the SHELL variable in your
/etc/ttytype terminal id to type map database
/usr/lib/terminfo terminal capability database
csh(1), sh(1), stty(1), environ(4), ttytype(4), terminfo(4).
For compatibility with earlier versions of tset, 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
-E c Sets the erase character to c only if the terminal can
- prints the terminal type on the standard output
-r prints the terminal type on the diagnostic output.
PPPPaaaaggggeeee 3333 [ Back ]