This program initializes terminals.
- First, tset retrieves the current terminal mode settings for your
+ First, tset retrieves the current terminal mode settings for your
terminal. It does this by successively testing
- o the standard error,
+ o the standard error,
- o standard output,
+ o standard output,
- o standard input and
+ o standard input and
- o ultimately "/dev/tty"
+ o ultimately "/dev/tty"
- to obtain terminal settings. Having retrieved these settings, tset
+ 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
+ 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.
+ 1. The terminal argument specified on the command line.
- 2. The value of the TERM environmental variable.
+ 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 convention, getty does this job by setting TERM
- according to the type passed to it by /etc/inittab.)
+ 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
+ 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
@@ -100,111 +100,111 @@
Once the terminal description is retrieved,
- o if the "-w" option is enabled, tset may update the terminal's
+ 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
+ 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
+ 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 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
+ 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 the terminal modes to "sane" values:
+ When invoked as reset, tset sets the terminal modes to "sane" values:
- o sets cooked and echo modes,
+ o sets cooked and echo modes,
- o turns off cbreak and raw modes,
+ o turns off cbreak and raw modes,
- o turns on newline translation and
+ o turns on newline translation and
- o resets any unset special characters to their default values
+ 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.
+ than using the terminal initialization strings, it uses the terminal
+ reset strings.
- The reset command is useful after a program dies leaving a terminal in
+ The reset command is useful after a program dies leaving a terminal in
an abnormal state:
- o you may have to type
+ o 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.
- o Also, the terminal will often not echo the command.
+ o Also, the terminal will often not echo the command.
The options are as follows:
- -c Set control characters and modes.
+ -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 strings to the
+ -I Do not send the terminal or tab initialization strings to the
terminal.
- -i Set the interrupt character to ch.
+ -i Set the interrupt character to ch.
- -k Set the line kill 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 information.
+ -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
+ -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 output, and the
+ -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.
+ -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 SETTINGTHE
- ENVIRONMENT 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
+ -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(3X).
- Normally this has no effect, unless setupterm is not able to
+ -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
+ 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.
+ 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.
+ using the -s option.
- When the -s option is specified, the commands to enter the information
+ 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:
+ 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 ... `
@@ -212,16 +212,16 @@
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
+ /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
+ 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
+ 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
@@ -231,149 +231,143 @@
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
+ 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
+ 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.
+ 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
+ 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.
+ 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
+ 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 (April 1979), written by Kurt Shoens.
- This program set the erase and kill characters to ^H (backspace) and @
+ A reset command appeared in 1BSD (March 1978), 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.
+ intr, quit, start/stop and eof characters as well as changing the
+ program to avoid modifying any user settings. That version of reset
+ did not use the termcap database.
- 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 1BSD by Eric Allman, using the
+ termcap database. Allman's comments in the source code indicate that
+ he began work in October 1977, continuing 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 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.
+ According to comments in the source code, the tset program was modified
+ in September 1980, to use logic copied from the 3BSD "reset" when it
+ was invoked as reset. This version appeared in 4.1cBSD, late in 1982.
Other developers (e.g., Keith Bostic and Jim Bloom) continued to modify
- tset until 4.4BSD was released in 1993.
+ tset until 4.4BSD was released in 1993.
- The ncurses implementation was lightly adapted from the 4.4BSD sources
+ 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.
+ (POSIX.1-2008) nor X/Open Curses Issue 7 documents tset or reset.
- The AT&T tput utility (AIX, HPUX, Solaris) incorporated the terminal-
+ 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.
+ 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.
+ 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:
+ 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
+ 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.
+ o The -s option only sets TERM, not TERMCAP.
- There was an undocumented 4.4BSD feature that invoking tset via a link
+ 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
+ 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
+ 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.
+ 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
+ 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
+ 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.
+ 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.
+ 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
+ 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
+ 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
+ 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.
+ To do this more easily, use the resize(1) program.
- The tset command uses these environment variables:
+ 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.
TERMCAP
may denote the location of a termcap database. If it is not an
- absolute pathname, e.g., begins with a "/", tset removes the
+ absolute pathname, e.g., begins with a "/", tset removes the
variable from the environment before looking for the terminal
description.
@@ -388,14 +382,14 @@