+
+</PRE><H3><a name="h3-CAPABILITY-VALUES">CAPABILITY VALUES</a></H3><PRE>
+ The <B>tgetflag</B> routine gets the boolean entry for <I>id</I>, or zero if it is
+ not available.
+
+ The <B>tgetnum</B> routine gets the numeric entry for <I>id</I>, or -1 if it is not
+ available.
+
+ The <B>tgetstr</B> routine returns the string entry for <I>id</I>, or zero if it is
+ not available. Use <B>tputs</B> to output the returned string. The <I>area</I> pa-
+ rameter is used as follows:
+
+ <B>o</B> It is assumed to be the address of a pointer to a buffer managed
+ by the calling application.
+
+ <B>o</B> However, ncurses checks to ensure that <B>area</B> is not NULL, and al-
+ so that the resulting buffer pointer is not NULL. If either
+ check fails, the <I>area</I> parameter is ignored.
+
+ <B>o</B> If the checks succeed, ncurses also copies the return value to
+ the buffer pointed to by <I>area</I>, and the <I>area</I> value will be updat-
+ ed to point past the null ending this value.
+
+ <B>o</B> The return value itself is an address in the terminal descrip-
+ tion which is loaded into memory.
+
+ Only the first two characters of the <B>id</B> parameter of <B>tgetflag</B>, <B>tgetnum</B>
+ and <B>tgetstr</B> are compared in lookups.
+
+
+</PRE><H3><a name="h3-FORMATTING-CAPABILITIES">FORMATTING CAPABILITIES</a></H3><PRE>
+ The <B>tgoto</B> routine expands the given capability using the parameters.
+
+ <B>o</B> Because the capability may have padding characters, the output of
+ <B>tgoto</B> should be passed to <B>tputs</B> rather than some other output func-
+ tion such as <B>printf</B>.
+
+ <B>o</B> While <B>tgoto</B> is assumed to be used for the two-parameter cursor po-
+ sitioning capability, termcap applications also use it for single-
+ parameter capabilities.
+
+ Doing this shows a quirk in <B>tgoto</B>: most hardware terminals use cur-
+ sor addressing with <I>row</I> first, but the original developers of the
+ termcap interface chose to put the <I>column</I> parameter first. The
+ <B>tgoto</B> function swaps the order of parameters. It does this also
+ for calls requiring only a single parameter. In that case, the
+ first parameter is merely a placeholder.
+
+ <B>o</B> Normally the ncurses library is compiled with terminfo support. In
+ that case, <B>tgoto</B> uses <B><A HREF="curs_terminfo.3X.html">tparm(3X)</A></B> (a more capable formatter).
+
+ However, <B>tparm</B> is not a <I>termcap</I> feature, and portable <I>termcap</I> ap-
+ plications should not rely upon its availability.
+
+ The <B>tputs</B> routine is described on the <B><A HREF="curs_terminfo.3X.html">curs_terminfo(3X)</A></B> manual page.
+ It can retrieve capabilities by either termcap or terminfo name.
+
+
+</PRE><H3><a name="h3-GLOBAL-VARIABLES">GLOBAL VARIABLES</a></H3><PRE>
+ The variables <B>PC</B>, <B>UP</B> and <B>BC</B> are set by <B>tgetent</B> to the terminfo entry's
+ data for <B>pad_char</B>, <B>cursor_up</B> and <B>backspace_if_not_bs</B>, respectively. <B>UP</B>
+ is not used by ncurses. <B>PC</B> is used in the <B>tdelay_output</B> function. <B>BC</B>
+ is used in the <B>tgoto</B> emulation. The variable <B>ospeed</B> is set by ncurses
+ in a system-specific coding to reflect the terminal speed.
+
+
+</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ Except where explicitly noted, routines that return an integer return
+ <B>ERR</B> upon failure and <B>OK</B> (SVr4 only specifies "an integer value other
+ than <B>ERR</B>") upon successful completion.
+
+ Routines that return pointers return <B>NULL</B> on error.
+
+
+</PRE><H2><a name="h2-BUGS">BUGS</a></H2><PRE>
+ If you call <B>tgetstr</B> to fetch <B>ca</B> or any other parameterized string, be
+ aware that it will be returned in terminfo notation, not the older and
+ not-quite-compatible termcap notation. This will not cause problems if
+ all you do with it is call <B>tgoto</B> or <B>tparm</B>, which both expand terminfo-
+ style strings as terminfo. (The <B>tgoto</B> function, if configured to sup-
+ port termcap, will check if the string is indeed terminfo-style by
+ looking for "%p" parameters or "$<..>" delays, and invoke a termcap-
+ style parser if the string does not appear to be terminfo).
+
+ Because terminfo conventions for representing padding in string capa-
+ bilities differ from termcap's, users can be surprised:
+
+ <B>o</B> <B>tputs("50")</B> in a terminfo system will put out a literal "50" rather
+ than busy-waiting for 50 milliseconds.
+
+ <B>o</B> However, if ncurses is configured to support termcap, it may also
+ have been configured to support the BSD-style padding.
+
+ In that case, <B>tputs</B> inspects strings passed to it, looking for dig-
+ its at the beginning of the string.
+
+ <B>tputs("50")</B> in a termcap system may wait for 50 milliseconds rather
+ than put out a literal "50"
+
+ Note that termcap has nothing analogous to terminfo's <B>sgr</B> string. One
+ consequence of this is that termcap applications assume <B>me</B> (terminfo
+ <B>sgr0</B>) does not reset the alternate character set. This implementation
+ checks for, and modifies the data shown to the termcap interface to ac-
+ commodate termcap's limitation in this respect.
+
+
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+
+</PRE><H3><a name="h3-Standards">Standards</a></H3><PRE>
+ These functions are provided for supporting legacy applications, and
+ should not be used in new programs:
+
+ <B>o</B> The XSI Curses standard, Issue 4 describes these functions. Howev-
+ er, they are marked TO BE WITHDRAWN and may be removed in future
+ versions.
+
+ <B>o</B> X/Open Curses, Issue 5 (December 2007) marked the termcap interface
+ (along with <B>vwprintw</B> and <B>vwscanw</B>) as withdrawn.
+
+ Neither the XSI Curses standard nor the SVr4 man pages documented the
+ return values of <B>tgetent</B> correctly, though all three were in fact re-
+ turned ever since SVr1. In particular, an omission in the XSI Curses
+ documentation has been misinterpreted to mean that <B>tgetent</B> returns <B>OK</B>
+ or <B>ERR</B>. Because the purpose of these functions is to provide compati-
+ bility with the <I>termcap</I> library, that is a defect in XCurses, Issue 4,
+ Version 2 rather than in ncurses.
+
+
+</PRE><H3><a name="h3-Compatibility-with-BSD-Termcap">Compatibility with BSD Termcap</a></H3><PRE>
+ External variables are provided for support of certain termcap applica-
+ tions. However, termcap applications' use of those variables is poorly
+ documented, e.g., not distinguishing between input and output. In par-
+ ticular, some applications are reported to declare and/or modify <B>os-</B>
+ <B>peed</B>.
+
+ The comment that only the first two characters of the <B>id</B> parameter are
+ used escapes many application developers. The original BSD 4.2 termcap
+ library (and historical relics thereof) did not require a trailing null
+ NUL on the parameter name passed to <B>tgetstr</B>, <B>tgetnum</B> and <B>tgetflag</B>.
+ Some applications assume that the termcap interface does not require
+ the trailing NUL for the parameter name. Taking into account these is-
+ sues:
+
+ <B>o</B> As a special case, <B>tgetflag</B> matched against a single-character
+ identifier provided that was at the end of the terminal descrip-
+ tion. You should not rely upon this behavior in portable programs.
+ This implementation disallows matches against single-character ca-
+ pability names.
+
+ <B>o</B> This implementation disallows matches by the termcap interface
+ against extended capability names which are longer than two charac-
+ ters.
+
+ The BSD termcap function <B>tgetent</B> returns the text of a termcap entry in
+ the buffer passed as an argument. This library (like other terminfo
+ implementations) does not store terminal descriptions as text. It sets
+ the buffer contents to a null-terminated string.
+
+
+</PRE><H3><a name="h3-Other-Compatibility">Other Compatibility</a></H3><PRE>
+ This library includes a termcap.h header, for compatibility with other
+ implementations. But the header is rarely used because the other im-
+ plementations are not strictly compatible.
+
+ The original BSD termcap (through 4.3BSD) had no header file which gave
+ function prototypes, because that was a feature of ANSI C. BSD termcap
+ was written several years before C was standardized. However, there
+ were two different termcap.h header files in the BSD sources:
+
+ <B>o</B> One was used internally by the <I>jove</I> editor in 2BSD through 4.4BSD.
+ It defined global symbols for the termcap variables which it used.
+
+ <B>o</B> The other appeared in 4.4BSD Lite Release 2 (mid-1993) as part of
+ <I>libedit</I> (also known as the <I>editline</I> library). The CSRG source his-
+ tory shows that this was added in mid-1992. The <I>libedit</I> header
+ file was used internally, as a convenience for compiling the <I>edit-</I>
+ <I>line</I> library. It declared function prototypes, but no global vari-
+ ables.
+
+ The header file from <I>libedit</I> was added to NetBSD's termcap library in
+ mid-1994.
+
+ Meanwhile, GNU termcap was under development, starting in 1990. The
+ first release (termcap 1.0) in 1991 included a termcap.h header. The
+ second release (termcap 1.1) in September 1992 modified the header to
+ use <B>const</B> for the function prototypes in the header where one would ex-
+ pect the parameters to be read-only. This was a difference versus the
+ original BSD termcap. The prototype for <B>tputs</B> also differed, but in
+ that instance, it was <I>libedit</I> which differed from BSD termcap.
+
+ A copy of GNU termcap 1.3 was bundled with <I>bash</I> in mid-1993, to support
+ the <I>readline</I> library.
+
+ A termcap.h file was provided in ncurses 1.8.1 (November 1993). That
+ reflected influence by <I>emacs</I> (rather than <I>jove</I>) and GNU termcap:
+
+ <B>o</B> it provided declarations for a few global symbols used by <I>emacs</I>
+
+ <B>o</B> it provided function prototypes (using <B>const</B>).
+
+ <B>o</B> a prototype for <B>tparam</B> (a GNU termcap feature) was provided.
+
+ Later (in mid-1996) the <B>tparam</B> function was removed from ncurses. As a
+ result, there are differences between any of the four implementations,
+ which must be taken into account by programs which can work with all
+ termcap library interfaces.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B>putc(3)</B>, <B><A HREF="term_variables.3X.html">term_variables(3X)</A></B>, <B><A HREF="terminfo.5.html">terminfo(5)</A></B>.
+
+ https://invisible-island.net/ncurses/tctest.html