- 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.
+
+ 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-
+ 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''.
+ 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
+ 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 ter-
- minal 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-
+ 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
+ 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 initializa-
- tion strings are sent to the standard 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.
- Use the -c or -w option to select only the window sizing
- versus the other initialization. If neither option is
- given, both are assumed.
+ tion strings are sent to the standard 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 transla-
tion and resets any unset special characters to their
@@ -107,17 +122,20 @@
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:
- -c Set control characters and modes. -e Set the erase
- character to ch.
+ -c Set control characters and modes.
+
+ -e Set the erase character to ch.
-I Do not send the terminal or tab initialization
strings to the terminal.
@@ -126,153 +144,182 @@
-k Set the line kill character to ch.
- -m Specify a mapping from a port type to a terminal.
+ -m Specify a mapping from a port type to a terminal.
See the section TERMINALTYPEMAPPING for more infor-
mation.
- -Q Do not display any values for the erase, interrupt
+ -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
+ values for control characters which differ from the
system's default values.
- -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.
+ -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.
-r Print the terminal type to the standard error output.
- -s Print the sequence of shell commands to initialize
+ -s Print the sequence of shell commands to initialize
the environment variable TERM to the standard output.
See the section SETTINGTHEENVIRONMENT for details.
-V reports the version of ncurses which was used in this
program, and exits.
- -w Resize the window to match the size deduced via
+ -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''.
+ entered as actual characters or by using the "hat" nota-
+ tion, i.e., control-h may be specified as "^H" or "^h".
+ If neither -c or -w is given, both options are assumed.
-
-
SETTING THE ENVIRONMENT
- It is often desirable to enter the terminal type and
- information about the terminal's capabilities into the
+
+
+ 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
+ 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 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
- often desirable to provide information about the type of
+ 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
type, an optional operator, an optional baud rate specifi-
- cation, an optional colon (``:'') character and a terminal
- type. The port type is a string (delimited by either the
+ 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
- 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-
+ 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:
+ 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 termi-
+ 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
+ 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
+ type will match any port type. For example, -mdialup: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
+ 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
- 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 (``!'').
+ 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 ("!").
-
-
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>.
+
+ 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.
-
-
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
+ 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,
+ 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.
+ 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-
@@ -284,50 +331,87 @@
and the terminal argument in some historic implementations
of tset has been removed.
-
-
-
ENVIRONMENT
+ 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
+ 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 `/',
+ is not an absolute pathname, e.g., begins with a "/",
tset removes the variable from the environment before
looking for the terminal description.
-
/etc/ttys
- system port name to terminal type mapping database
+ system port name to terminal type mapping database
(BSD versions only).
/usr/share/terminfo
terminal capability database
-