Manual Pages  — tput

 tput - initialize a terminal, exercise its capabilities, or query  term info database

SYNOPSIS DESCRIPTION Operands Aliases Terminal Size OPTIONS EXIT STATUS ENVIRONMENT FILES PORTABILITY HISTORY EXAMPLES SEE ALSO

tput [-T terminal-type] {cap-code [parameter ...amp;]} ...

tput [-T terminal-type] [-x] clear

tput [-T terminal-type] init

tput [-T terminal-type]  reset

tput [-T terminal-type]  longname

tput -S

tput -V

 tput uses the  term info library and database to make terminal-specific capabilities and information available to the shell, to initialize or reset the terminal, or to report a description of the current (or specified) terminal type. Terminal capabilities are accessed by cap-code.

 terminfo(5) discusses terminal capabilities at length and presents a complete list of cap-codes.

When retrieving capability values, the result depends upon the capability's type.

Boolean	tput sets its exit status to 0 if the terminal possesses cap-code, and 1 if it does not.
numeric	tput writes cap-code's decimal value to the standard output stream if defined (-1 if it is not) followed by a newline.
string	tput writes cap-code's value to the standard output stream if defined, without a trailing newline.

Before using a value returned on the standard output, the application should test  tput's exit status to be sure it is 0; see section EXIT STATUS below.

Generally, an operand is a cap-code, a capability code from the terminal database, or a parameter thereto. Three others are specially recognized by  tput: init,  reset, and  longname. Although these resemble capability codes, they in fact receive special handling; we term them pseudo-capabilities.

cap-code
	indicates a capability from the terminal database.
	If cap-code is of string type and takes parameters,  tput interprets arguments following cap-code as the parameters, up to the (fixed) quantity the capability requires.
	Most parameters are numeric. Only a few terminal capabilities 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	initializes the terminal. If the terminal database is present and an entry for the user's terminal type exists, the following occur. (1)  tput retrieves the terminal's mode settings. It successively tests the file descriptors corresponding to » the standard error stream, » the standard output stream, » the standard input stream, and »  /dev/tty to obtain terminal settings. Having retrieved them,  tput remembers which descriptor to use for further updates. (2) If the terminal dimensions cannot be obtained from the operating system, but the environment or terminal type database entry describes them,  tput updates the operating system's notion of them. (3)  tput updates the terminal modes. » Any delays specified in the entry (for example, when a newline is sent) are set in the terminal driver. » Tab expansion is turned on or off per the specification in the entry, and » if tabs are not expanded, standard tabs (every 8 spaces) are set. (4) If initialization capabilities, detailed in subsection Tabs and Initialization of  terminfo(5), are present,  tput writes them to the standard output stream. (5)  tput flushes the standard output stream.
	If an entry lacks the information needed for an activity above, that activity is silently skipped.
reset	re-initializes the terminal. A reset differs from initialization in two ways. (1)  tput sets the the terminal modes to a sane state, » enabling cooked and echo modes, » disabling cbreak and raw modes, » enabling newline translation, and » setting any unset special characters to their default values. (2) If any reset capabilities are defined for the terminal type,  tput writes them to the output stream. Otherwise,  tput uses any defined initialization capabilities. Reset capabilities are detailed in subsection Tabs and Initialization of  terminfo(5).
longname
	A  term info entry begins with one or more names by which an application can refer to the entry, before the list of terminal capabilities. The names are separated by | characters. X/Open Curses terms the last name the long name, and indicates that it may include blanks.
	tic warns if the last name does not include blanks, to accommodate old  term info entries that treated the long name as an optional feature. The long name is often referred to as the description field.
	If the terminal database is present and an entry for the user's terminal type exists,  tput reports its description to the standard output stream, without a trailing newline. See  terminfo(5).

Note: Redirecting the output of  tput init or  tput reset to a file will capture only part of their actions. Changes to the terminal modes are not affected by file descriptor redirection, since the terminal modes are altered via  ioctl(2).

If  tput is invoked via link with any of the names clear, init, or  reset, it operates as if run with the corresponding (pseudo-)capability operand. For example, executing a link named  reset that points to  tput has the same effect as  tput  reset.

This feature was introduced by  ncurses 5.2 in 2000. It is rarely used:

clear	is a separate program, which is both smaller and more frequently executed.
init	has the same name as another program in widespread use.
reset	is provided by the  tset(1) utility (also via a link named  reset).

Besides the pseudo-capabilities (such as init),  tput treats the lines and cols cap-codes specially: it may call  setupterm(3X) to obtain the terminal size.

»	First,  tput attempts to obtain these capabilities from the terminal database. This generally fails for terminal emulators, which lack a fixed window size and thus omit the capabilities.
»	It then asks the operating system for the terminal's size, which generally works, unless the connection is via a serial line that does not support NAWS: negotiations about window size.
»	Finally, it inspects the environment variables LINES and  COLUMNS, 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, ultimately, the terminal database).

-S	retrieves more than one capability per invocation of  tput. The capabilities must be passed to  tput from the standard input stream instead of from the command line (see section EXAMPLES below). Only one cap-code is allowed per line. The -S option changes the meanings of the 0 and 1 exit statuses (see section EXIT STATUS below).
	Some capabilities use string parameters rather than numeric ones.  tput employs a built-in table and the presence of parameters in its input to decide how to interpret them, and whether to use  tparm(3X).
-T type	indicates the terminal's type. Normally this option is unnecessary, because a default is taken from the TERM environment variable. If specified, the environment variables LINES and  COLUMNS are also ignored.
-V	reports the version of  ncurses associated with  tput, and exits with a successful status.
-x	prevents  tput clear from attempting to clear the scrollback buffer.

Normally, one should interpret  tput's exit statuses as follows.

When the -S option is used, some statuses change meanings.

tput reads one environment variable.

TERM	denotes the terminal type. Each terminal type is distinct, though many are similar. The -T option overrides its value.

/usr/share/tabset
	tab stop initialization database
/usr/share/misc/terminfo	compiled terminal description database

Over time  ncurses  tput has differed from that of System V in two important respects, one now mostly historical.

»	tput cap-code writes to the standard output, which need not be a terminal device. However, the operands that manipulate terminal modes might not use the standard output.
	System V tput's init and  reset operands use logic from 4.1cBSD tset, manipulating terminal modes. It checks the same file descriptors (and  /dev/tty) for association with a terminal device as  ncurses now does, and if none are, finally assumes a 1200 baud terminal. When updating terminal modes, it ignores errors.
	Until  ncurses 6.1 (see section HISTORY below),  tput did not modify terminal modes. It now employs a scheme similar to System V, using functions shared with  tset (and ultimately based on 4.4BSD tset). If it is not able to open a terminal (for instance, when run by cron(1)),  tput exits with an error status.
»	System V tput assumes that the type of a cap-code operand is numeric if all the characters of its value are decimal numbers; if they are not, it treats cap-code as a string capability.
	Most implementations that provide support for cap-code operands use the  tparm(3X) function to expand its parameters. That function expects a mixture of numeric and string parameters, requiring  tput to know which type to use.
	ncurses  tput uses a table to determine the parameter types for the standard cap-code operands, and an internal function to analyze nonstandard cap-code operands.
	While more reliable than System V's utility, a portability problem is introduced by this analysis. An OpenBSD developer adapted the internal library function from  ncurses to port NetBSD's termcap-based tput to  term info, and modified it to interpret multiple cap-codes (and parameters) on the command line. Portable applications should not rely upon this feature;  ncurses offers it to support applications written specifically for OpenBSD.

This implementation, unlike others, accepts both termcap and  term info cap-codes if termcap support is compiled in. In that case, however, the predefined termcap and  term info codes have two ambiguities;  ncurses assumes the  term info code.

»	The cap-code dl means  delete_line to termcap but  parm_delete_line to  term info. termcap uses the code DL for  parm_delete_line.  term info uses the code dl1 for  delete_line.
»	The cap-code ed means  exit_delete_mode to termcap but  clr_eos to  term info. termcap uses the code cd for  clr_eos.  term info uses the code rmdc for  exit_delete_mode.

The  longname operand, -S option, and the parameter-substitution features used in the cup example below, were not supported in AT&T/USL curses before SVr4 (1989). Later, 4.3BSD-Reno (1990) added support for  longname, and in 1994, NetBSD added support for the parameter-substitution features.

IEEE Std 1003.1/The Open Group Base Specifications Issue 7 (POSIX.1-2008) documents only the clear, init, and  reset operands. A few observations of interest arise from that selection.

»	ncurses supports clear as it does any other standard cap-code. The others (init and  longname) do not correspond to terminal capabilities.
»	The tput on SVr4-based systems such as Solaris, IRIX64, and HP-UX, as well as others such as AIX and Tru64, also support standard cap-code operands.
»	A few platforms such as FreeBSD recognize termcap codes rather than  term info capability codes in their respective tput commands. Since 2010, NetBSD's tput uses  term info codes. Before that, it (like FreeBSD) recognized termcap codes.
	Beginning in 2021, FreeBSD uses  ncurses tput, configured for both  term info (tested first) and termcap (as a fallback).

Because (apparently) all certified Unix systems support the full set of capability codes, the reason for documenting only a few may not be apparent.

»	X/Open Curses Issue 7 documents tput differently, with cap-code 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 capability database.
»	While it is certainly possible to write a tput program without using curses, no system with a curses implementation provides a tput utility that does not also support standard cap-codes.

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 (that is, System V curses behavior).

»	It assigns exit status 4 to invalid operand, which may have the same meaning as unknown capability. For instance, the source code for Solaris xcurses uses the term invalid in this case.
»	It assigns exit status 255 to a numeric variable that is not specified in the  term info database. That likely is a documentation error, mistaking the -1 written to the standard output to indicate an absent or cancelled numeric capability for an (unsigned) exit status.

The various System V implementations (AIX, HP-UX, Solaris) use the same exit statuses as  ncurses.

NetBSD curses documents exit statuses that correspond to neither  ncurses nor X/Open Curses.

Bill Joy wrote a tput command during development of 4BSD in October 1980. This initial version only cleared the screen, and did not ship with official distributions.

System V developed a different tput command.

»	SVr2 (1984) provided a rudimentary tput that checked the parameter against each predefined capability and returned the corresponding value. This version of tput did not use  tparm(3X) for parameterized capabilities.
»	SVr3 (1987) replaced that with a more extensive program whose support for init and  reset operands (more than half the program) incorporated the  reset feature of BSD tset written by Eric Allman.
»	SVr4 (1989) added color initialization by using the  orig_colors (oc) and  orig_pair (op) capabilities in its init logic.

Keith Bostic refactored BSD tput for shipment in 4.3BSD-Tahoe (1988), then replaced it the next year with a new implementation based on System V tput. Bostic's version similarly accepted some parameters named for  term info (pseudo-)capabilities: clear, init,  longname, and  reset. However, because he had only termcap available, it accepted termcap codes for other capabilities. Also, Bostic's BSD tput did not modify the terminal modes as the earlier BSD tset had done.

At the same time, Bostic added a shell script named clear that used tput to clear the screen. Both of these appeared in 4.4BSD, becoming the modern BSD implementation of tput.

The origin of  ncurses  tput lies outside both System V and BSD, in 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 program. Eric Raymond used that tput program (and other parts of  mytinfo) in  ncurses in June 1995. Incorporating the portions dealing with terminal capabilities almost without change, Raymond made improvements to the way command-line parameters were handled.

Before  ncurses 6.1 (2018), its  tset and  tput utilities differed.

»	tset was more effective, resetting the terminal modes and special characters.
»	On the other hand,  tset's repertoire of terminal capabilities for resetting the terminal was more limited; it had only equivalents of  reset_1string (rs1),  reset_2string (rs2), and  reset_file (rf), and not the tab stop and margin update features of  tput.

The  reset program is traditionally an alias for  tset due to its ability to reset terminal modes and special characters.

As of  ncurses 6.1, the reset features of the two programs are (mostly) the same. Two minor differences remain.

»	The  tset program waits one second when resetting, in case the terminal happens to be a hardware device.
»	The two programs write the terminal initialization strings to different streams; that is, standard error for  tset and standard output for  tput.

tput init
	Initialize the terminal according to the type of terminal in the TERM environment variable. If the system does not reliably initialize the terminal upon login, this command can be included in  $HOME/.profile after exporting the TERM environment variable.
tput -T5620 reset
	Reset an AT&T 5620 terminal, overriding the terminal type in the TERM environment variable.
tput cnorm
	Set cursor to normal visibility.
tput home
	Move the cursor to row 0, column 0: the upper left corner of the screen, usually known as the home cursor position.
tput clear
	Clear the screen: write the  clear_screen capability's value to the standard output stream.
tput cols
	Report the number of columns used by the current terminal type.
tput -Tadm3a cols
	Report the number of columns used by an ADM-3A terminal.
strong=`tput smso` normal=`tput rmso`
	Set shell variables to capability values: strong and normal, to begin and end, respectively, stand-out mode for the terminal. One might use these to present a prompt.
	printf "${strong}Username:${normal} "
tput hc
	Indicate via exit status whether the terminal is a hard copy device.
tput cup 23 4
	Move the cursor to row 23, column 4.
tput cup
	Report the value of the  cursor_address (cup) capability (used for cursor movement), with no parameters substituted.
tput longname
	Report the  term info database's description of the terminal type specified in the TERM environment variable.
tput -S
	Process multiple capabilities. The -S option can be profitably used with a shell here document.
	$ tput -S <<! > clear > cup 10 10 > bold > !
	The foregoing clears the screen, moves the cursor to position (10, 10) and turns on bold (extra bright) mode.
tput clear cup 10 10 bold
	Perform the same actions as the foregoing  tput -S example.

 clear(1),  stty(1),  tabs(1),  tset(1),  curs_termcap(3X),  terminfo(5)