tput(1) [freebsd man page]
TPUT(1) BSD General Commands Manual TPUT(1) NAME
tput, clear -- terminal capability interface SYNOPSIS
tput [-T term] attribute ... clear DESCRIPTION
The tput utility makes terminal-dependent information available to users or shell applications. When invoked as the clear utility, the screen will be cleared as if tput clear had been executed. The options to tput are as follows: -T The terminal name as specified in the termcap(5) database, for example, ``vt100'' or ``xterm''. If not specified, tput retrieves the ``TERM'' variable from the environment. The tput utility outputs a string for each attribute that is of type string; a number for each of type integer. Otherwise, tput exits 0 if the terminal has the capability and 1 if it does not, without further action. If an attribute is of type string, and takes arguments (e.g. cursor movement, the termcap ``cm'' sequence) the arguments are taken from the command line immediately following the attribute. The following special attributes are available: clear Clear the screen (the termcap(5) ``cl'' sequence). init Initialize the terminal (the termcap(5) ``is'' sequence). longname Print the descriptive name of the user's terminal type. reset Reset the terminal (the termcap(5) ``rs'' sequence). EXIT STATUS
The exit status of tput is as follows: 0 If the last attribute attribute argument is of type string or integer, its value was successfully written to standard output. If the argument is of type boolean, the terminal has this attribute. 1 This terminal does not have the specified boolean attribute. 2 Usage error. 3 No information is available about the specified terminal type. SEE ALSO
termcap(5), terminfo(5) STANDARDS
The tput utility conforms to IEEE Std 1003.1-2001 (``POSIX.1''). HISTORY
The tput utility appeared in 4.4BSD. BUGS
The tput utility cannot really distinguish between different types of attributes. Some termcap entries depend upon having a '%' in them that is just a '%' and nothing more. Right now we just warn about them if they do not have a valid type declaration. These warnings are sent to stderr. BSD
June 15, 2002 BSD
Check Out this Related Man Page
clear(1) General Commands Manual clear(1) NAME
clear - clear the terminal screen SYNOPSIS
clear [-Ttype] [-V] [-x] DESCRIPTION
clear clears your screen if this is possible, including its scrollback buffer (if the extended "E3" capability is defined). clear looks in the environment for the terminal type given by the environment variable TERM, and then in the terminfo database to determine how to clear the screen. clear writes to the standard output. You can redirect the standard output to a file (which prevents clear from actually clearing the screen), and later cat the file to the screen, clearing it at that point. OPTIONS
-T type indicates the type of terminal. Normally this option is unnecessary, because the default is taken from the environment 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 program, and exits. The options are as follows: -x do not attempt to clear the terminal's scrollback buffer using the extended "E3" capability. HISTORY
A clear command appeared in 2.79BSD dated February 24, 1979. Later that was provided in Unix 8th edition (1985). AT&T adapted a different BSD program (tset) to make a new command (tput), and used this to replace the clear command with a shell script which calls tput clear, e.g., /usr/bin/tput ${1:+-T$1} clear 2> /dev/null exit In 1989, when Keith Bostic revised the BSD tput command to make it similar to the AT&T tput, he added a shell script for the clear command: exec tput clear The remainder of the script in each case is a copyright notice. The ncurses clear command began in 1995 by adapting the original BSD clear command (with terminfo, of course). The E3 extension came later: o In June 1999, xterm provided an extension to the standard control sequence for clearing the screen. Rather than clearing just the vis- ible part of the screen using printf ' 33[2J' one could clear the scrollback using printf ' 33[3J' This is documented in XTerm Control Sequences as a feature originating with xterm. o A few other terminal developers adopted the feature, e.g., PuTTY in 2006. o In April 2011, a Red Hat developer submitted a patch to the Linux kernel, modifying its console driver to do the same thing. The Linux change, part of the 3.0 release, did not mention xterm, although it was cited in the Red Hat bug report (#683733) which led to the change. o Again, a few other terminal developers adopted the feature. But the next relevant step was a change to the clear program in 2013 to incorporate this extension. o In 2013, the E3 extension was overlooked in tput with the "clear" parameter. That was addressed in 2016 by reorganizing tput to share its logic with clear and tset. PORTABILITY
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 latter documents tput, which could be used to replace this utility either via a shell script or by an alias (such as a symbolic link) to run tput as clear. SEE ALSO
tput(1), terminfo(5) This describes ncurses version 6.1 (patch 20180127). clear(1)