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tput(1) General Commands Manual tput(1)
NAME
tput, reset - initialize a terminal or query terminfo database
SYNOPSIS
tput [-Ttype] capname [parameters]
tput [-Ttype] [-x] clear
tput [-Ttype] init
tput [-Ttype] reset
tput [-Ttype] longname
tput -S <<
tput -V
DESCRIPTION
The tput utility uses the terminfo database to make the values of
terminal-dependent capabilities and information available to the
shell (see sh(1)), to initialize or reset the terminal, or return
the long name of the requested terminal type. The result depends
upon the capability's type:
string
tput writes the string to the standard output. No trail‐
ing newline is supplied.
integer
tput writes the decimal value to the standard output, with
a trailing newline.
boolean
tput simply sets the exit code (0 for TRUE if the terminal
has the capability, 1 for FALSE if it does not), and
writes nothing to the standard output.
Before using a value returned on the standard output, the applica‐
tion should test the exit code (e.g., $?, see sh(1)) to be sure it
is 0. (See the EXIT CODES and DIAGNOSTICS sections.) For a com‐
plete list of capabilities and the capname associated with each,
see terminfo(5).
Options
-S allows more than one capability per invocation of tput.
The capabilities must be passed to tput from the standard
input instead of from the command line (see example). Only
one capname is allowed per line. The -S option changes the
meaning of the 0 and 1 boolean and string exit codes (see
the EXIT CODES section).
Because some capabilities may use string parameters rather
than numbers, tput uses a table and the presence of parame‐
ters in its input to decide whether to use tparm(3X), and
how to interpret the parameters.
-Ttype indicates the type of terminal. Normally this option is
unnecessary, because the default is taken from the environ‐
ment variable TERM. If -T is specified, then the shell
variables LINES and COLUMNS will also be ignored.
-V reports the version of ncurses which was used in this pro‐
gram, and exits.
-x do not attempt to clear the terminal's scrollback buffer
using the extended “E3” capability.
Commands
A few commands (init, reset and longname) are special; they are
defined by the tput program. The others are the names of capabil‐
ities from the terminal database (see terminfo(5) for a list).
Although init and reset resemble capability names, tput uses sev‐
eral capabilities to perform these special functions.
capname
indicates the capability from the terminal database.
If the capability is a string that takes parameters, the
arguments following the capability will be used as parame‐
ters for the string.
Most parameters are numbers. Only a few terminal capabili‐
ties require string parameters; tput uses a table to decide
which to pass as strings. Normally tput uses tparm(3X) to
perform the substitution. If no parameters are given for
the capability, tput writes the string without performing
the substitution.
init If the terminal database is present and an entry for the
user's terminal exists (see -Ttype, above), the following
will occur:
(1) first, tput retrieves the current terminal mode set‐
tings for your terminal. It does this by successively
testing
· the standard error,
· standard output,
· standard input and
· ultimately “/dev/tty”
to obtain terminal settings. Having retrieved these
settings, tput remembers which file descriptor to use
when updating settings.
(2) if the window size cannot be obtained from the operat‐
ing system, but the terminal description (or environ‐
ment, e.g., LINES and COLUMNS variables specify this),
update the operating system's notion of the window
size.
(3) the terminal modes will be updated:
· any delays (e.g., newline) specified in the entry
will be set in the tty driver,
· tabs expansion will be turned on or off according
to the specification in the entry, and
· if tabs are not expanded, standard tabs will be
set (every 8 spaces).
(4) if present, the terminal's initialization strings will
be output as detailed in the terminfo(5) section on
Tabs and Initialization,
(5) output is flushed.
If an entry does not contain the information needed for any
of these activities, that activity will silently be
skipped.
reset This is similar to init, with two differences:
(1) before any other initialization, the terminal modes
will be reset to a “sane” state:
· set cooked and echo modes,
· turn off cbreak and raw modes,
· turn on newline translation and
· reset any unset special characters to their
default values
(2) Instead of putting out initialization strings, the
terminal's reset strings will be output if present
(rs1, rs2, rs3, rf). If the reset strings are not
present, but initialization strings are, the initial‐
ization strings will be output.
Otherwise, reset acts identically to init.
longname
If the terminal database is present and an entry for the
user's terminal exists (see -Ttype above), then the long
name of the terminal will be put out. The long name is the
last name in the first line of the terminal's description
in the terminfo database [see term(5)].
Aliases
tput handles the clear, init and reset commands specially: it
allows for the possibility that it is invoked by a link with those
names.
If tput is invoked by a link named reset, this has the same effect
as tput reset. The tset(1) utility also treats a link named reset
specially.
Before ncurses 6.1, the two utilities were different from each
other:
· tset utility reset the terminal modes and special characters
(not done with tput).
· On the other hand, tset's repertoire of terminal capabilities
for resetting the terminal was more limited, i.e., only
reset_1string, reset_2string and reset_file in contrast to the
tab-stops and margins which are set by this utility.
· The reset program is usually an alias for tset, because of
this difference with resetting terminal modes and special
characters.
With the changes made for ncurses 6.1, the reset feature of the
two programs is (mostly) the same. A few differences remain:
· The tset program waits one second when resetting, in case it
happens to be a hardware terminal.
· The two programs write the terminal initialization strings to
different streams (i.e., the standard error for tset and the
standard output for tput).
Note: although these programs write to different streams,
redirecting their output to a file will capture only part of
their actions. The changes to the terminal modes are not
affected by redirecting the output.
If tput is invoked by a link named init, this has the same effect
as tput init. Again, you are less likely to use that link because
another program named init has a more well-established use.
Terminal Size
Besides the special commands (e.g., clear), tput treats certain
terminfo capabilities specially: lines and columns. tput calls
setupterm(3X) to obtain the terminal size:
· first, it gets the size from the terminal database (which gen‐
erally is not provided for terminal emulators which do not
have a fixed window size)
· then it asks the operating system for the terminal's size
(which generally works, unless connecting via a serial line
which does not support NAWS: negotiations about window size).
· finally, it inspects the environment variables LINES and COL‐
UMNS which may override the terminal size.
If the -T option is given tput ignores the environment variables
by calling use_tioctl(TRUE), relying upon the operating system (or
finally, the terminal database).
EXAMPLES
tput init
Initialize the terminal according to the type of terminal in
the environmental variable TERM. This command should be
included in everyone's .profile after the environmental vari‐
able TERM has been exported, as illustrated on the profile(5)
manual page.
tput -T5620 reset
Reset an AT&T 5620 terminal, overriding the type of terminal
in the environmental variable TERM.
tput cup 0 0
Send the sequence to move the cursor to row 0, column 0 (the
upper left corner of the screen, usually known as the “home”
cursor position).
tput clear
Echo the clear-screen sequence for the current terminal.
tput cols
Print the number of columns for the current terminal.
tput -T450 cols
Print the number of columns for the 450 terminal.
bold=`tput smso` offbold=`tput rmso`
Set the shell variables bold, to begin stand-out mode
sequence, and offbold, to end standout mode sequence, for the
current terminal. This might be followed by a prompt: echo
"${bold}Please type in your name: ${offbold}\c"
tput hc
Set exit code to indicate if the current terminal is a hard
copy terminal.
tput cup 23 4
Send the sequence to move the cursor to row 23, column 4.
tput cup
Send the terminfo string for cursor-movement, with no parame‐
ters substituted.
tput longname
Print the long name from the terminfo database for the type
of terminal specified in the environmental variable TERM.
tput -S <<!
> clear
> cup 10 10
> bold
> !
This example shows tput processing several capabilities in
one invocation. It clears the screen, moves the cursor to
position 10, 10 and turns on bold (extra bright) mode. The
list is terminated by an exclamation mark (!) on a line by
itself.
FILES
/usr/share/terminfo
compiled terminal description database
/usr/share/tabset/*
tab settings for some terminals, in a format appropriate to
be output to the terminal (escape sequences that set mar‐
gins and tabs); for more information, see the Tabs and Ini‐
tialization, section of terminfo(5)
EXIT CODES
If the -S option is used, tput checks for errors from each line,
and if any errors are found, will set the exit code to 4 plus the
number of lines with errors. If no errors are found, the exit
code is 0. No indication of which line failed can be given so
exit code 1 will never appear. Exit codes 2, 3, and 4 retain
their usual interpretation. If the -S option is not used, the
exit code depends on the type of capname:
boolean
a value of 0 is set for TRUE and 1 for FALSE.
string a value of 0 is set if the capname is defined for this
terminal type (the value of capname is returned on stan‐
dard output); a value of 1 is set if capname is not
defined for this terminal type (nothing is written to
standard output).
integer
a value of 0 is always set, whether or not capname is
defined for this terminal type. To determine if capname
is defined for this terminal type, the user must test
the value written to standard output. A value of -1
means that capname is not defined for this terminal
type.
other reset or init may fail to find their respective files.
In that case, the exit code is set to 4 + errno.
Any other exit code indicates an error; see the DIAGNOSTICS sec‐
tion.
DIAGNOSTICS
tput prints the following error messages and sets the correspond‐
ing exit codes.
exit code error message
─────────────────────────────────────────────────────────────────────
0 (capname is a numeric variable that is not specified in
the terminfo(5) database for this terminal type, e.g.
tput -T450 lines and tput -T2621 xmc)
1 no error message is printed, see the EXIT CODES section.
2 usage error
3 unknown terminal type or no terminfo database
4 unknown terminfo capability capname
>4 error occurred in -S
─────────────────────────────────────────────────────────────────────
HISTORY
The tput command was begun by Bill Joy in 1980. The initial ver‐
sion only cleared the screen.
AT&T System V provided a different tput command, whose init and
reset subcommands (more than half the program) were incorporated
from the reset feature of BSD tset written by Eric Allman.
Keith Bostic replaced the BSD tput command in 1989 with a new
implementation based on the AT&T System V program tput. Like the
AT&T program, Bostic's version accepted some parameters named for
terminfo capabilities (clear, init, longname and reset). However
(because he had only termcap available), it accepted termcap names
for other capabilities. Also, Bostic's BSD tput did not modify
the terminal I/O modes as the earlier BSD tset had done.
At the same time, Bostic added a shell script named “clear”, which
used tput to clear the screen.
Both of these appeared in 4.4BSD, becoming the “modern” BSD imple‐
mentation of tput.
This implementation of tput began from a different source than
AT&T or BSD: Ross Ridge's mytinfo package, published on
comp.sources.unix in December 1992. Ridge's program made more
sophisticated use of the terminal capabilities than the BSD pro‐
gram. Eric Raymond used that tput program (and other parts of
mytinfo) in ncurses in June 1995. Using the portions dealing with
terminal capabilities almost without change, Raymond made improve‐
ments to the way the command-line parameters were handled.
PORTABILITY
This implementation of tput differs from AT&T tput in two impor‐
tant areas:
· tput capname writes to the standard output. That need not be
a regular terminal. However, the subcommands which manipulate
terminal modes may not use the standard output.
The AT&T implementation's init and reset commands use the BSD
(4.1c) tset source, which manipulates terminal modes. It suc‐
cessively tries standard output, standard error, standard
input before falling back to “/dev/tty” and finally just
assumes a 1200Bd terminal. When updating terminal modes, it
ignores errors.
Until changes made after ncurses 6.0, tput did not modify ter‐
minal modes. tput now uses a similar scheme, using functions
shared with tset (and ultimately based on the 4.4BSD tset).
If it is not able to open a terminal, e.g., when running in
cron, tput will return an error.
· AT&T tput guesses the type of its capname operands by seeing
if all of the characters are numeric, or not.
Most implementations which provide support for capname oper‐
ands use the tparm function to expand parameters in it. That
function expects a mixture of numeric and string parameters,
requiring tput to know which type to use.
This implementation uses a table to determine the parameter
types for the standard capname operands, and an internal
library function to analyze nonstandard capname operands.
This implementation (unlike others) can accept both termcap and
terminfo names for the capname feature, if termcap support is com‐
piled in. However, the predefined termcap and terminfo names have
two ambiguities in this case (and the terminfo name is assumed):
· The termcap name dl corresponds to the terminfo name dl1
(delete one line).
The terminfo name dl corresponds to the termcap name DL
(delete a given number of lines).
· The termcap name ed corresponds to the terminfo name rmdc (end
delete mode).
The terminfo name ed corresponds to the termcap name cd (clear
to end of screen).
The longname and -S options, and the parameter-substitution fea‐
tures used in the cup example, were not supported in BSD curses
before 4.3reno (1989) or in AT&T/USL curses before SVr4 (1988).
IEEE Std 1003.1/The Open Group Base Specifications Issue 7
(POSIX.1-2008) documents only the operands for clear, init and
reset. There are a few interesting observations to make regarding
that:
· In this implementation, clear is part of the capname support.
The others (init and longname) do not correspond to terminal
capabilities.
· Other implementations of tput on SVr4-based systems such as
Solaris, IRIX64 and HPUX as well as others such as AIX and
Tru64 provide support for capname operands.
· A few platforms such as FreeBSD recognize termcap names rather
than terminfo capability names in their respective tput com‐
mands. Since 2010, NetBSD's tput uses terminfo names. Before
that, it (like FreeBSD) recognized termcap names.
Because (apparently) all of the certified Unix systems support the
full set of capability names, the reasoning for documenting only a
few may not be apparent.
· X/Open Curses Issue 7 documents tput differently, with capname
and the other features used in this implementation.
· That is, there are two standards for tput: POSIX (a subset)
and X/Open Curses (the full implementation). POSIX documents
a subset to avoid the complication of including X/Open Curses
and the terminal capabilities database.
· While it is certainly possible to write a tput program without
using curses, none of the systems which have a curses imple‐
mentation provide a tput utility which does not provide the
capname feature.
X/Open Curses Issue 7 (2009) is the first version to document
utilities. However that part of X/Open Curses does not follow
existing practice (i.e., Unix features documented in SVID 3):
· It assigns exit code 4 to “invalid operand”, which may be the
same as unknown capability. For instance, the source code for
Solaris' xcurses uses the term “invalid” in this case.
· It assigns exit code 255 to a numeric variable that is not
specified in the terminfo database. That likely is a documen‐
tation error, confusing the -1 written to the standard output
for an absent or cancelled numeric value versus an (unsigned)
exit code.
The various Unix systems (AIX, HPUX, Solaris) use the same exit-
codes as ncurses.
NetBSD curses documents different exit codes which do not corre‐
spond to either ncurses or X/Open.
SEE ALSO
clear(1), stty(1), tabs(1), tset(1), terminfo(5), curs_term‐
cap(3X).
This describes ncurses version 6.1 (patch 20191109).
tput(1)