- 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 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 con-
- firms 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.
+
+
+ This program initializes terminals.
+
+ First, tset retrieves the current terminal mode settings
+ for your terminal. It does this by successively testing
+
+ o the standard error,
+
+ o standard output,
+
+ o standard input and
+
+ o ultimately "/dev/tty"
+
+ to obtain terminal settings. Having retrieved these set-
+ tings, tset remembers which file descriptor to use when
+ updating settings.
+
+ Next, tset 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 System-V-like UNIXes and systems using that conven-
+ tion, 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 TERMINALTYPEMAPPING for more information).
+ Then, if the terminal type begins with a question mark
+ ("?"), the user is prompted for confirmation of the termi-
+ nal 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 ter-
+ minal type.
Once the terminfo entry is retrieved, the window size,
backspace, interrupt and line kill characters (among many
@@ -53,7 +112,9 @@
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,
+
+
+ When invoked as reset, tset sets cooked and echo modes,
turns off cbreak and raw modes, turns on newline transla-
tion and resets any unset special characters to their
default values before doing the terminal initialization
@@ -61,243 +122,296 @@
leaving a terminal in an abnormal state. Note, you may
have to type
- <LF>reset<LF>
+ <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:
- -q The terminal type is displayed to the standard out-
- put, and the terminal is not initialized in any way.
- The option `-' by itself is equivalent but archaic.
+ -c Set control characters and modes.
- -e Set the erase character to ch.
+ -e Set the erase character to ch.
- -I Do not send the terminal or tab initialization
+ -I Do not send the terminal or tab initialization
strings to the terminal.
- -Q Don't display any values for the erase, interrupt and
- line kill characters.
+ -i Set the interrupt character to ch.
- -V reports the version of ncurses which was used in this
- program, and exits.
+ -k Set the line kill character to ch.
+
+ -m Specify a mapping from a port type to a terminal.
+ See the section TERMINALTYPEMAPPING for more infor-
+ mation.
- -i Set the interrupt character to ch.
+ -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.
- -k Set the line kill character to ch.
+ -q The terminal type is displayed to the standard out-
+ put, and the terminal is not initialized in any way.
+ The option "-" by itself is equivalent but archaic.
- -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.
- -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 SETTINGTHEENVIRONMENT for details.
- -s Print the sequence of shell commands to initialize
- the environment variable TERM to the standard output.
- See the section below on setting the environment for
- details.
+ -V reports the version of ncurses which was used in this
+ program, and exits.
- The arguments for the -e, -i, and -k options may either be
- entered as actual characters or by using the `hat' nota-
- tion, i.e. control-h may be specified as ``^H'' or ``^h''.
+ -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" nota-
+ tion, i.e., control-h may be specified as "^H" or "^h".
-
-
SETTING THE ENVIRONMENT
+ If neither -c or -w is given, both options are assumed.
+
+
+
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.
+ shell's environment. This is done using the -s option.
- When the -s option is specified, the commands to enter the
+ 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
+ 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 ... `
-
-
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
+ 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 -m options maps from some set of conditions to a ter-
+ minal type, that is, to tell tset "If I'm on this port at
+ a particular speed, guess that I'm on that kind of termi-
+ nal".
- The argument to the -m option consists of an optional port
+ The argument to the -m option consists of an optional port
type, an optional operator, an optional baud rate specifi-
- cation, an optional colon (``:'') character and a terminal
+ cation, 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.
+ 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
+ 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 applica-
ble mapping is used.
For example, consider the following mapping:
- dialup>9600:vt100. The port type is dialup , the operator
+ dialup>9600:vt100. The port type is dialup , the operator
is >, the baud rate specification is 9600, and the termi-
nal type is vt100. The result of this mapping is to spec-
- ify that if the terminal type is dialup, and the baud rate
- is greater than 9600 baud, a terminal type of vt100 will
+ ify 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,
+ 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
+ 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 exclama-
- tion marks (``!'').
-
-
-
-
HISTORY
- The tset command appeared in BSD 3.0. The ncurses imple-
- mentation was lightly adapted from the 4.4BSD sources for
- a terminfo environment by Eric S. Raymond <esr@snark.thyr-
- sus.com>.
-
-
-
-
COMPATIBILITY
- The tset utility has been provided for backward-compati-
- bility 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 begin-
- ning 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 recom-
- mended 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 the SHELL and TERM environment vari-
- ables.
-
-
-
-
FILES
- /etc/ttys
- system port name to terminal type mapping database
- (BSD versions only).
-
- /usr/share/terminfo
- terminal capability database
-
-
-
-
SEE ALSO
- csh(1), sh(1), stty(1), tty(4), termcap(5), ttys(5), envi-
- ron(7)
-
-
-
-
-
-
+ 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 ("!").
+
+ A reset command appeared in 2BSD (1979), written by Kurt
+ Shoens.
+ A separate tset command was provided in 2BSD by Eric All-
+ man. While the oldest published source (from 1979) pro-
+ vides both programs, Allman's comments in the 2BSD source
+ code indicate that he began work in October 1977, continu-
+ ing development over the next few years.
+ In 1980, Eric Allman modified tset to provide a "reset"
+ feature when the program was invoked as reset.
+ The ncurses implementation was lightly adapted from the
+ 4.4BSD sources for a terminfo environment by Eric S. Ray-
+ mond <esr@snark.thyrsus.com>.
+
+ Neither IEEE Std 1003.1/The Open Group Base Specifications
+ Issue 7 (POSIX.1-2008) nor X/Open Curses Issue 7 documents
+ tset or reset.
+ The AT&T tput utility (AIX, HPUX, Solaris) incorporated
+ the terminal-mode manipulation as well as termcap-based
+ features such as resetting tabstops from tset in BSD
+ (4.1c), presumably with the intention of making tset obso-
+ lete. However, each of those systems still provides tset.
+ In fact, the commonly-used reset utility is always an
+ alias for tset.
+ The tset utility provides 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.
+ A few options are different because the TERMCAP variable
+ is no longer supported under terminfo-based ncurses:
+ o The -S option of BSD tset no longer works; it prints
+ an error message to the standard error and dies.
+ o The -s option only sets TERM, not TERMCAP.
+ There was an undocumented 4.4BSD feature that invoking
+ tset via a link named "TSET" (or via any other name begin-
+ ning 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 -a,
+ -d, and -p options are therefore omitted from the usage
+ summary above.
+
+ Very old systems, e.g., 3BSD, used a different terminal
+ driver which was replaced in 4BSD in the early 1980s. To
+ accommodate these older systems, the 4BSD tset provided a
+ -n option to specify that the new terminal driver should
+ be used. This implementation does not provide that
+ choice.
+
+ It is still permissible to specify the -e, -i, and -k
+ options without arguments, although it is strongly recom-
+ mended 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 -c and -w options are not found in earlier implementa-
+ tions. However, a different window size-change feature
+ was provided in 4.4BSD.
+ o In 4.4BSD, tset uses the window size from the termcap
+ description to set the window size if tset is not able
+ to obtain the window size from the operating system.
+ o In ncurses, tset obtains the window size using
+ setupterm, which may be from the operating system, the
+ LINES and COLUMNS environment variables or the termi-
+ nal description.
+ Obtaining the window size from the terminal description is
+ common to both implementations, but considered obsoles-
+ cent. Its only practical use is for hardware terminals.
+ Generally speaking, a window size would be unset only if
+ there were some problem obtaining the value from the oper-
+ ating system (and setupterm would still fail). For that
+ reason, the LINES and COLUMNS environment variables may be
+ useful for working around window-size problems. Those
+ have the drawback that if the window is resized, those
+ variables must be recomputed and reassigned. To do this
+ more easily, use the resize(1) program.
+
+ 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.
+