Manual Pages for UNIX Darwin command on man tset

tset(1) tset(1)

NAME

ttsseett, rreesseett - terminal initialization

SYNOPSIS

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

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

DESCRIPTION

TTsseett initializes terminals. TTsseett first determines the type of terminal that you are using. This determination is done as follows, using the first terminal type found. 1. The tteerrmmiinnaall argument specified on the command line. 2. The value of the TTEERRMM 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 TTEERRMM 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 -mm

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 rreesseett, ttsseett 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 <>rreesseett<>

(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:

-qq 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.

-ee Set the erase character to ch.

-II Do not send the terminal or tab initialization strings to the ter-

minal.

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

characters.

-VV reports the version of ncurses which was used in this program, and

exits.

-ii Set the interrupt character to ch.

-kk Set the line kill character to ch.

-mm Specify a mapping from a port type to a terminal. See below for

more information.

-rr Print the terminal type to the standard error output.

-ss Print the sequence of shell commands to initialize the environment

variable TTEERRMM to the standard output. See the section below on setting the environment for details.

The arguments for the -ee, -ii, and -kk 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 -ss option.

When the -ss option is specified, the commands to enter the information

into the shell's environment are written to the standard output. If the SSHHEELLLL environmental variable ends in ``csh'', the commands are for ccsshh, otherwise, they are for sshh. Note, the ccsshh commands set and unset the shell variable nnoogglloobb, leaving it unset. The following line in the ..llooggiinn or ..pprrooffiillee files will initialize the environment correctly:

eval `tset -s options ... `

TTEERRMMIINNAALL TTYYPPEE MMAAPPPPIINNGG

When the terminal is not hardwired into the system (or the current sys-

tem information is incorrect) the terminal type derived from the /etc/ttys file or the TTEERRMM environmental variable is often something generic like nneettwwoorrkk, ddiiaalluupp, or uunnkknnoowwnn. When ttsseett 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 -mm option is to map from some set of conditions to a

terminal type, that is, to tell ttsseett ``If I'm on this port at a partic-

ular speed, guess that I'm on that kind of terminal''.

The argument to the -mm 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 opera-

tor 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 -mm 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: ddiiaalluupp>>99660000::vvtt110000. 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 ddiiaalluupp, and the baud rate is greater than 9600 baud, a terminal type of vvtt110000 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, -mm ddiiaalluupp::vvtt110000 -mm ::??xxtteerrmm 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 -mm option argument.

Also, to avoid problems with meta-characters, it is suggested that the

entire -mm option argument be placed within single quote characters, and

that ccsshh users insert a backslash character (``\'') before any exclama-

tion marks (``!''). HISTORY The ttsseett command appeared in BSD 3.0. The nnccuurrsseess implementation was lightly adapted from the 4.4BSD sources for a terminfo environment by Eric S. Raymond . CCOOMMPPAATTIIBBIILLIITTYY

The ttsseett utility has been provided for backward-compatibility with BSD

environments (under most modern UNIXes, //eettcc//iinniittttaabb and getty(1) can

set TTEERRMM appropriately for each dial-up line; this obviates what was

ttsseett's most important use). This implementation behaves like 4.4BSD

tset, with a few exceptions specified here.

The -SS option of BSD tset no longer works; it prints an error message

to stderr and dies. The -ss option only sets TTEERRMM, not TTEERRMMCCAAPP. Both

these changes are because the TTEERRMMCCAAPP variable is no longer supported

under terminfo-based nnccuurrsseess, which makes ttsseett -SS 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

omitted.

The -AA, -EE, -hh, -uu and -vv options were deleted from the ttsseett utility in

4.4BSD. None of them were documented in 4.3BSD and all are of limited

utility at best. The -aa, -, 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 -mm option

instead. The -n option remains, but has no effect. The -aaddnnpp options

are therefore omitted from the usage summary above.

It is still permissible to specify the -ee, -ii, and -kk options without

arguments, although it is strongly recommended that such usage be fixed to explicitly specify the character.

As of 4.4BSD, executing ttsseett as rreesseett no longer implies the -QQ option.

Also, the interaction between the - option and the terminal argument in

some historic implementations of ttsseett has been removed. ENVIRONMENT The ttsseett command uses the SSHHEELLLL and TTEERRMM environment variables. FILES /etc/ttys system port name to terminal type mapping database (BSD versions only). /usr/share/terminfo terminal capability database