+
+</PRE><H2><a name="h2-EXIT-STATUS">EXIT STATUS</a></H2><PRE>
+ Normally, one should interpret <STRONG>tput</STRONG>'s exit statuses as follows.
+
+ <STRONG>Status</STRONG> <STRONG>Meaning</STRONG> <STRONG>When</STRONG> <STRONG>-S</STRONG> <STRONG>Not</STRONG> <STRONG>Specified</STRONG>
+ ------------------------------------------------------------------------
+ <STRONG>0</STRONG> Boolean or string capability present
+ <STRONG>1</STRONG> Boolean or numeric capability absent
+ <STRONG>2</STRONG> usage error or no terminal type specified
+ <STRONG>3</STRONG> unrecognized terminal type
+ <STRONG>4</STRONG> unrecognized capability code
+ <STRONG>>4</STRONG> system error (4 + <STRONG>errno</STRONG>)
+
+ When the <STRONG>-S</STRONG> option is used, some statuses change meanings.
+
+ <STRONG>Status</STRONG> <STRONG>Meaning</STRONG> <STRONG>When</STRONG> <STRONG>-S</STRONG> <STRONG>Specified</STRONG>
+ ------------------------------------------------------------------------
+ <STRONG>0</STRONG> all operands interpreted
+ <STRONG>1</STRONG> unused
+ <STRONG>4</STRONG> some operands not interpreted
+
+
+</PRE><H2><a name="h2-ENVIRONMENT">ENVIRONMENT</a></H2><PRE>
+ <STRONG>tput</STRONG> reads one environment variable.
+
+ <EM>TERM</EM> denotes the terminal type. Each terminal type is distinct,
+ though many are similar. The <STRONG>-T</STRONG> option overrides its value.
+
+
+</PRE><H2><a name="h2-FILES">FILES</a></H2><PRE>
+ <EM>/usr/share/tabset</EM>
+ tab stop initialization database
+
+ <EM>/usr/share/terminfo</EM>
+ compiled terminal description database
+
+
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ Over time <EM>ncurses</EM> <STRONG>tput</STRONG> has differed from that of System V in two
+ important respects, one now mostly historical.
+
+ <STRONG>o</STRONG> "<STRONG>tput</STRONG> <EM>cap-code</EM>" 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 <STRONG>tput</STRONG>'s <STRONG>init</STRONG> and <STRONG>reset</STRONG> operands use logic from 4.1cBSD
+ <STRONG>tset</STRONG>, manipulating terminal modes. It checks the same file
+ descriptors (and <EM>/dev/tty</EM>) for association with a terminal device
+ as <EM>ncurses</EM> now does, and if none are, finally assumes a 1200 baud
+ terminal. When updating terminal modes, it ignores errors.
+
+ Until <EM>ncurses</EM> 6.1 (see section "HISTORY" below), <STRONG>tput</STRONG> did not
+ modify terminal modes. It now employs a scheme similar to
+ System V, using functions shared with <STRONG>tset</STRONG> (and ultimately based on
+ 4.4BSD <STRONG>tset</STRONG>). If it is not able to open a terminal (for instance,
+ when run by <STRONG>cron(1)</STRONG>), <STRONG>tput</STRONG> exits with an error status.
+
+ <STRONG>o</STRONG> System V <STRONG>tput</STRONG> assumes that the type of a <EM>cap-code</EM> operand is
+ numeric if all the characters of its value are decimal numbers; if
+ they are not, it treats <EM>cap-code</EM> as a string capability.
+
+ Most implementations that provide support for <EM>cap-code</EM> operands use
+ the <STRONG><A HREF="curs_terminfo.3x.html">tparm(3x)</A></STRONG> function to expand its parameters. That function
+ expects a mixture of numeric and string parameters, requiring <STRONG>tput</STRONG>
+ to know which type to use.
+
+ <EM>ncurses</EM> <STRONG>tput</STRONG> uses a table to determine the parameter types for the
+ standard <EM>cap-code</EM> operands, and an internal function to analyze
+ nonstandard <EM>cap-code</EM> 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 <EM>ncurses</EM> to port NetBSD's <EM>termcap</EM>-
+ based <STRONG>tput</STRONG> to <EM>terminfo</EM>, and modified it to interpret multiple <EM>cap-</EM>
+ <EM>codes</EM> (and parameters) on the command line. Portable applications
+ should not rely upon this feature; <EM>ncurses</EM> offers it to support
+ applications written specifically for OpenBSD.
+
+ This implementation, unlike others, accepts both <EM>termcap</EM> and <EM>terminfo</EM>
+ <EM>cap-codes</EM> if <EM>termcap</EM> support is compiled in. In that case, however,
+ the predefined <EM>termcap</EM> and <EM>terminfo</EM> codes have two ambiguities; <EM>ncurses</EM>
+ assumes the <EM>terminfo</EM> code.
+
+ <STRONG>o</STRONG> The <EM>cap-code</EM> <STRONG>dl</STRONG> means <STRONG>delete_line</STRONG> to <EM>termcap</EM> but <STRONG>parm_delete_line</STRONG>
+ to <EM>terminfo</EM>. <EM>termcap</EM> uses the code <STRONG>DL</STRONG> for <STRONG>parm_delete_line</STRONG>. <EM>term-</EM>
+ <EM>info</EM> uses the code <STRONG>dl1</STRONG> for <STRONG>delete_line</STRONG>.
+
+ <STRONG>o</STRONG> The <EM>cap-code</EM> <STRONG>ed</STRONG> means <STRONG>exit_delete_mode</STRONG> to <EM>termcap</EM> but <STRONG>clr_eos</STRONG> to
+ <EM>terminfo</EM>. <EM>termcap</EM> uses the code <STRONG>cd</STRONG> for <STRONG>clr_eos</STRONG>. <EM>terminfo</EM> uses the
+ code <STRONG>rmdc</STRONG> for <STRONG>exit_delete_mode</STRONG>.
+
+ The <STRONG>longname</STRONG> operand, <STRONG>-S</STRONG> option, and the parameter-substitution
+ features used in the <STRONG>cup</STRONG> example below, were not supported in AT&T/USL
+ <EM>curses</EM> before SVr4 (1989). Later, 4.3BSD-Reno (1990) added support for
+ <STRONG>longname</STRONG>, 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 <STRONG>clear</STRONG>, <STRONG>init</STRONG>, and <STRONG>reset</STRONG> operands. A
+ few observations of interest arise from that selection.
+
+ <STRONG>o</STRONG> <EM>ncurses</EM> supports <STRONG>clear</STRONG> as it does any other standard <EM>cap-code</EM>. The
+ others (<STRONG>init</STRONG> and <STRONG>longname</STRONG>) do not correspond to terminal
+ capabilities.
+
+ <STRONG>o</STRONG> The <STRONG>tput</STRONG> on SVr4-based systems such as Solaris, IRIX64, and HP-UX,
+ as well as others such as AIX and Tru64, also support standard <EM>cap-</EM>
+ <EM>code</EM> operands.
+
+ <STRONG>o</STRONG> A few platforms such as FreeBSD recognize <EM>termcap</EM> codes rather than
+ <EM>terminfo</EM> capability codes in their respective <STRONG>tput</STRONG> commands. Since
+ 2010, NetBSD's <STRONG>tput</STRONG> uses <EM>terminfo</EM> codes. Before that, it (like
+ FreeBSD) recognized <EM>termcap</EM> codes.
+
+ Beginning in 2021, FreeBSD uses <EM>ncurses</EM> <STRONG>tput</STRONG>, configured for both
+ <EM>terminfo</EM> (tested first) and <EM>termcap</EM> (as a fallback).
+
+ Because (apparently) all <EM>certified</EM> Unix systems support the full set of
+ capability codes, the reason for documenting only a few may not be
+ apparent.
+
+ <STRONG>o</STRONG> X/Open Curses Issue 7 documents <STRONG>tput</STRONG> differently, with <EM>cap-code</EM> and
+ the other features used in this implementation.
+
+ <STRONG>o</STRONG> That is, there are two standards for <STRONG>tput</STRONG>: 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.
+
+ <STRONG>o</STRONG> While it is certainly possible to write a <STRONG>tput</STRONG> program without
+ using <EM>curses</EM>, no system with a <EM>curses</EM> implementation provides a
+ <STRONG>tput</STRONG> utility that does not also support standard <EM>cap-codes</EM>.
+
+ 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 <EM>curses</EM> behavior).
+
+ <STRONG>o</STRONG> It assigns exit status 4 to "invalid operand", which may have the
+ same meaning as "unknown capability". For instance, the source
+ code for Solaris <EM>xcurses</EM> uses the term "invalid" in this case.
+
+ <STRONG>o</STRONG> It assigns exit status 255 to a numeric variable that is not
+ specified in the <EM>terminfo</EM> 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 <EM>ncurses</EM>.
+
+ NetBSD <EM>curses</EM> documents exit statuses that correspond to neither
+ <EM>ncurses</EM> nor X/Open Curses.
+
+
+</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
+ Bill Joy wrote a <STRONG>tput</STRONG> 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 <STRONG>tput</STRONG> command.
+
+ <STRONG>o</STRONG> SVr2 (1984) provided a rudimentary <STRONG>tput</STRONG> that checked the parameter
+ against each predefined capability and returned the corresponding
+ value. This version of <STRONG>tput</STRONG> did not use <STRONG><A HREF="curs_terminfo.3x.html">tparm(3x)</A></STRONG> for
+ parameterized capabilities.
+
+ <STRONG>o</STRONG> SVr3 (1987) replaced that with a more extensive program whose
+ support for <STRONG>init</STRONG> and <STRONG>reset</STRONG> operands (more than half the program)
+ incorporated the <STRONG>reset</STRONG> feature of BSD <STRONG>tset</STRONG> written by Eric Allman.
+
+ <STRONG>o</STRONG> SVr4 (1989) added color initialization by using the <STRONG>orig_colors</STRONG>
+ (<STRONG>oc</STRONG>) and <STRONG>orig_pair</STRONG> (<STRONG>op</STRONG>) capabilities in its <STRONG>init</STRONG> logic.
+
+ Keith Bostic refactored BSD <STRONG>tput</STRONG> for shipment in 4.3BSD-Tahoe (1988),
+ then replaced it the next year with a new implementation based on
+ System V <STRONG>tput</STRONG>. Bostic's version similarly accepted some parameters
+ named for <EM>terminfo</EM> (pseudo-)capabilities: <STRONG>clear</STRONG>, <STRONG>init</STRONG>, <STRONG>longname</STRONG>, and
+ <STRONG>reset</STRONG>. However, because he had only <EM>termcap</EM> available, it accepted
+ <EM>termcap</EM> codes for other capabilities. Also, Bostic's BSD <STRONG>tput</STRONG> did not
+ modify the terminal modes as the earlier BSD <STRONG>tset</STRONG> had done.
+
+ At the same time, Bostic added a shell script named "clear" that used
+ <STRONG>tput</STRONG> to clear the screen. Both of these appeared in 4.4BSD, becoming
+ the "modern" BSD implementation of <STRONG>tput</STRONG>.
+
+ The origin of <EM>ncurses</EM> <STRONG>tput</STRONG> lies outside both System V and BSD, in Ross
+ Ridge's <EM>mytinfo</EM> package, published on <EM>comp.sources.unix</EM> in December
+ 1992. Ridge's program made more sophisticated use of the terminal
+ capabilities than the BSD program. Eric Raymond used that <STRONG>tput</STRONG> program
+ (and other parts of <EM>mytinfo</EM>) in <EM>ncurses</EM> 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 <EM>ncurses</EM> 6.1 (2018), its <STRONG>tset</STRONG> and <STRONG>tput</STRONG> utilities differed.
+
+ <STRONG>o</STRONG> <STRONG>tset</STRONG> was more effective, resetting the terminal modes and special
+ characters.
+
+ <STRONG>o</STRONG> On the other hand, <STRONG>tset</STRONG>'s repertoire of terminal capabilities for
+ resetting the terminal was more limited; it had only equivalents of
+ <STRONG>reset_1string</STRONG> (<STRONG>rs1</STRONG>), <STRONG>reset_2string</STRONG> (<STRONG>rs2</STRONG>), and <STRONG>reset_file</STRONG> (<STRONG>rf</STRONG>), and
+ not the tab stop and margin update features of <STRONG>tput</STRONG>.
+
+ The <STRONG>reset</STRONG> program is traditionally an alias for <STRONG>tset</STRONG> due to its ability
+ to reset terminal modes and special characters.
+
+ As of <EM>ncurses</EM> 6.1, the "reset" features of the two programs are
+ (mostly) the same. Two minor differences remain.
+
+ <STRONG>o</STRONG> The <STRONG>tset</STRONG> program waits one second when resetting, in case the
+ terminal happens to be a hardware device.
+
+ <STRONG>o</STRONG> The two programs write the terminal initialization strings to
+ different streams; that is, standard error for <STRONG>tset</STRONG> and standard
+ output for <STRONG>tput</STRONG>.