+ <STRONG>o</STRONG> AT&T <STRONG>tput</STRONG> guesses the type of its <EM>capname</EM> operands by seeing if all
+ of the characters are numeric, or not.
+
+ Most implementations which provide support for <EM>capname</EM> operands use
+ the <EM>tparm</EM> function to expand parameters in it. That function
+ expects a mixture of numeric and string parameters, requiring <STRONG>tput</STRONG>
+ to know which type to use.
+
+ This implementation uses a table to determine the parameter types
+ for the standard <EM>capname</EM> operands, and an internal library function
+ to analyze nonstandard <EM>capname</EM> operands.
+
+ This implementation (unlike others) can accept both <EM>termcap</EM> and <EM>ter-</EM>
+ <EM>minfo</EM> names for the <EM>capname</EM> feature, if <EM>termcap</EM> support is compiled in.
+ However, the predefined <EM>termcap</EM> and <EM>terminfo</EM> names have two ambiguities
+ in this case (and the <EM>terminfo</EM> name is assumed):
+
+ <STRONG>o</STRONG> The <EM>termcap</EM> name <STRONG>dl</STRONG> corresponds to the <EM>terminfo</EM> name <STRONG>dl1</STRONG> (delete
+ one line).
+ The <EM>terminfo</EM> name <STRONG>dl</STRONG> corresponds to the <EM>termcap</EM> name <STRONG>DL</STRONG> (delete a
+ given number of lines).
+
+ <STRONG>o</STRONG> The <EM>termcap</EM> name <STRONG>ed</STRONG> corresponds to the <EM>terminfo</EM> name <STRONG>rmdc</STRONG> (end
+ delete mode).
+ The <EM>terminfo</EM> name <STRONG>ed</STRONG> corresponds to the <EM>termcap</EM> name <STRONG>cd</STRONG> (clear to
+ end of screen).
+
+ The <STRONG>longname</STRONG> and <STRONG>-S</STRONG> options, and the parameter-substitution features
+ used in the <STRONG>cup</STRONG> 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 <STRONG>clear</STRONG>, <STRONG>init</STRONG> and <STRONG>reset</STRONG>.
+ There are a few interesting observations to make regarding that:
+
+ <STRONG>o</STRONG> In this implementation, <STRONG>clear</STRONG> is part of the <EM>capname</EM> support. The
+ others (<STRONG>init</STRONG> and <STRONG>longname</STRONG>) do not correspond to terminal capabili-
+ ties.
+
+ <STRONG>o</STRONG> Other implementations of <STRONG>tput</STRONG> on SVr4-based systems such as
+ Solaris, IRIX64 and HPUX as well as others such as AIX and Tru64
+ provide support for <EM>capname</EM> operands.
+
+ <STRONG>o</STRONG> A few platforms such as FreeBSD recognize termcap names rather than
+ terminfo capability names in their respective <STRONG>tput</STRONG> commands. Since
+ 2010, NetBSD's <STRONG>tput</STRONG> uses terminfo names. Before that, it (like
+ FreeBSD) recognized termcap names.
+
+ Because (apparently) <EM>all</EM> of the certified Unix systems support the full
+ set of capability names, the reasoning for documenting only a few may
+ not be apparent.
+
+ <STRONG>o</STRONG> X/Open Curses Issue 7 documents <STRONG>tput</STRONG> differently, with <EM>capname</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 termi-
+ nal capabilities database.
+
+ <STRONG>o</STRONG> While it is certainly possible to write a <STRONG>tput</STRONG> program without
+ using curses, none of the systems which have a curses implementa-
+ tion provide a <STRONG>tput</STRONG> utility which does not provide the <EM>capname</EM> fea-
+ ture.
+
+ X/Open Curses Issue 7 (2009) is the first version to document utili-
+ ties. However that part of X/Open Curses does not follow existing
+ practice (i.e., Unix features documented in SVID 3):
+
+ <STRONG>o</STRONG> It assigns exit code 4 to "invalid operand", which may be the same
+ as <EM>unknown</EM> <EM>capability</EM>. For instance, the source code for Solaris'
+ xcurses uses the term "invalid" in this case.
+
+ <STRONG>o</STRONG> It assigns exit code 255 to a numeric variable that is not speci-
+ fied in the terminfo database. That likely is a documentation
+ error, confusing the <STRONG>-1</STRONG> 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 correspond to
+ either ncurses or X/Open.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>, <STRONG>stty(1)</STRONG>, <STRONG><A HREF="tabs.1.html">tabs(1)</A></STRONG>, <STRONG><A HREF="tset.1.html">tset(1)</A></STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>, <STRONG><A HREF="curs_termcap.3x.html">curs_termcap(3x)</A></STRONG>.