This program initializes terminals.
- First, tset retrieves the current terminal mode settings
- for your terminal. It does this by successively testing
+ First, tset retrieves the current terminal mode settings for your
+ terminal. It does this by successively testing
o the standard error,
@@ -72,62 +71,82 @@
o ultimately "/dev/tty"
- to obtain terminal settings. Having retrieved these set-
- tings, tset remembers which file descriptor to use when
- updating settings.
+ to obtain terminal settings. Having retrieved these settings, 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.
+ 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.)
+ 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 convention, 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
- 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.
+ 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
+ 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 terminal description for the terminal is retrieved. If
+ no terminal description is found for the type, the user is prompted for
+ another terminal type.
+
+ Once the terminal description is retrieved,
+
+ o if the "-w" option is enabled, tset may update the terminal's
+ window size.
+
+ If the window size cannot be obtained from the operating system,
+ but the terminal description (or environment, e.g., LINES and
+ COLUMNS variables specify this), use this to set the operating
+ system's notion of the window size.
+
+ o if the "-c" option is enabled, the backspace, interrupt and line
+ kill characters (among many other things) are set
+
+ o unless the "-I" option is enabled, the terminal and tab
+ initialization strings are sent to the standard error output, and
+ tset waits one second (in case a hardware reset was issued).
+
+ o 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
- 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
+ When invoked as reset, tset sets the terminal modes to "sane" values:
+
+ o sets cooked and echo modes,
+
+ o turns off cbreak and raw modes,
+
+ o turns on newline translation and
+
+ o resets any unset special characters to their default values
+
+ before doing the terminal initialization described above. Also, rather
+ than using the terminal initialization strings, it uses the terminal
+ reset strings.
- <LF>reset<LF>
+ The reset command is useful after a program dies leaving a terminal in
+ an abnormal state:
- (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.
+ o you may have to type
+
+ <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.
+
+ o Also, the terminal will often not echo the command.
@@ -137,261 +156,246 @@
-e Set the erase character to ch.
- -I Do not send the terminal or tab initialization
- strings to the terminal.
+ -I Do not send the terminal or tab initialization strings to the
+ terminal.
-i Set the interrupt character to ch.
-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.
+ -m Specify a mapping from a port type to a terminal. See the section
+ TERMINALTYPEMAPPING for more information.
- -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.
+ -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.
- -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 output, 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
- 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 SETTINGTHE
+ ENVIRONMENT for details.
- -V reports the version of ncurses which was used in this
- program, and exits.
+ -V reports the version of ncurses which was used in this program, and
+ exits.
- -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.
+ -w Resize the window to match the size deduced via setupterm(3x).
+ 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".
+ The arguments for the -e, -i, and -k 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".
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.
-
- 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
- environment correctly:
+ 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 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
- terminal used on such ports.
-
- 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
- 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.
-
- 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-
- ble mapping is used.
-
- 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-
- 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
- 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,
- 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
- 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 ("!").
+ 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 terminal used on such ports.
+
+ The -m options maps 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 argument to the -m 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
+ 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.
+
+ 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 applicable mapping is used.
+
+ 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 terminal type is vt100. The result of this mapping is to
+ specify 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, -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 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
+ exclamation marks ("!").
- A reset command appeared in 2BSD (1979), written by Kurt
- Shoens.
+ A reset command appeared in 2BSD (April 1979), written by Kurt Shoens.
+ This program set the erase and kill characters to ^H (backspace) and @
+ respectively. Mark Horton improved that in 3BSD (October 1979), adding
+ intr, quit, start/stop and eof characters as well as changing the
+ program to avoid modifying any user settings.
+
+ Later in 4.1BSD (December 1980), Mark Horton added a call to the tset
+ program using the -I and -Q options, i.e., using that to improve the
+ terminal modes. With those options, that version of reset did not use
+ the termcap database.
- 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.
+ A separate tset command was provided in 2BSD by Eric Allman. While the
+ oldest published source (from 1979) provides both tset and reset,
+ Allman's comments in the 2BSD source code indicate that he began work
+ in October 1977, continuing development over the next few years.
- In 1980, Eric Allman modified tset to provide a "reset"
- feature when the program was invoked as reset.
+ In September 1980, Eric Allman modified tset, adding the code from the
+ existing "reset" feature when tset was invoked as reset. Rather than
+ simply copying the existing program, in this merged version, tset used
+ the termcap database to do additional (re)initialization of the
+ terminal. This version appeared in 4.1cBSD, late in 1982.
- The ncurses implementation was lightly adapted from the
- 4.4BSD sources for a terminfo environment by Eric S. Ray-
- mond <esr@snark.thyrsus.com>.
+ Other developers (e.g., Keith Bostic and Jim Bloom) continued to modify
+ tset until 4.4BSD was released in 1993.
+
+ The ncurses implementation was lightly adapted from the 4.4BSD sources
+ for a terminfo environment by Eric S. Raymond <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.
+ 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 obsolete. 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.
+ 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
+ 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 recommended 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 implementations.
+ 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 terminal description.
+
+ Obtaining the window size from the terminal description is common to
+ both implementations, but considered obsolescent. 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
+ operating 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.
+ 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.
+ 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.
+ 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.
/etc/ttys
- system port name to terminal type mapping database
- (BSD versions only).
+ system port name to terminal type mapping database (BSD versions
+ only).
/usr/share/terminfo
terminal capability database