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- * @Id: curs_termcap.3x,v 1.31 2015/04/26 00:49:10 tom Exp @
+ * @Id: curs_termcap.3x,v 1.32 2016/03/19 22:52:25 tom Exp @
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</PRE><H3><a name="h3-FORMATTING-CAPABILITIES">FORMATTING CAPABILITIES</a></H3><PRE>
- The <STRONG>tgoto</STRONG> routine instantiates the parameters into the
- given capability. The output from this routine is to be
- passed to <STRONG>tputs</STRONG>.
-
- The <STRONG>tputs</STRONG> routine is described on the <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
+ The <STRONG>tgoto</STRONG> routine expands the given capability using the
+ parameters.
+
+ <STRONG>o</STRONG> Because the capability may have padding characters,
+ the output of <STRONG>tgoto</STRONG> should be passed to <STRONG>tputs</STRONG> rather
+ than some other output function such as <STRONG>printf</STRONG>.
+
+ <STRONG>o</STRONG> While <STRONG>tgoto</STRONG> is assumed to be used for the two-parame-
+ ter cursor positioning capability, termcap applica-
+ tions also use it for single-parameter capabilities.
+
+ Doing this shows a quirk in <STRONG>tgoto</STRONG>: most hardware ter-
+ minals use cursor addressing with <EM>row</EM> first, but the
+ original developers of the termcap interface chose to
+ put the <EM>column</EM> parameter first. The <STRONG>tgoto</STRONG> 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.
+
+ <STRONG>o</STRONG> Normally the ncurses library is compiled with terminfo
+ support. In that case, <STRONG>tgoto</STRONG> uses <STRONG>tparm</STRONG> (a more capa-
+ ble formatter).
+
+ The <STRONG>tputs</STRONG> routine is described on the <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
manual page. It can retrieve capabilities by either term-
cap or terminfo name.
</PRE><H3><a name="h3-GLOBAL-VARIABLES">GLOBAL VARIABLES</a></H3><PRE>
The variables <STRONG>PC</STRONG>, <STRONG>UP</STRONG> and <STRONG>BC</STRONG> are set by <STRONG>tgetent</STRONG> to the ter-
minfo entry's data for <STRONG>pad_char</STRONG>, <STRONG>cursor_up</STRONG> and
- <STRONG>backspace_if_not_bs</STRONG>, respectively. <STRONG>UP</STRONG> is not used by
+ <STRONG>backspace_if_not_bs</STRONG>, respectively. <STRONG>UP</STRONG> is not used by
ncurses. <STRONG>PC</STRONG> is used in the <STRONG>tdelay_output</STRONG> function. <STRONG>BC</STRONG> is
- used in the <STRONG>tgoto</STRONG> emulation. The variable <STRONG>ospeed</STRONG> is set
+ used in the <STRONG>tgoto</STRONG> emulation. The variable <STRONG>ospeed</STRONG> is set
by ncurses in a system-specific coding to reflect the ter-
minal speed.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
Except where explicitly noted, routines that return an in-
- teger return <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> (SVr4 only specifies
+ teger return <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> (SVr4 only specifies
"an integer value other than <STRONG>ERR</STRONG>") upon successful comple-
tion.
</PRE><H2><a name="h2-BUGS">BUGS</a></H2><PRE>
If you call <STRONG>tgetstr</STRONG> to fetch <STRONG>ca</STRONG> or any other parameterized
- string, be aware that it will be returned in terminfo no-
+ string, be aware that it will be returned in terminfo no-
tation, not the older and not-quite-compatible termcap no-
- tation. This will not cause problems if all you do with
- it is call <STRONG>tgoto</STRONG> or <STRONG>tparm</STRONG>, which both expand terminfo-
- style strings as terminfo. (The <STRONG>tgoto</STRONG> function, if con-
- figured to support termcap, will check if the string is
- indeed terminfo-style by looking for "%p" parameters or
- "$<..>" delays, and invoke a termcap-style parser if the
+ tation. This will not cause problems if all you do with
+ it is call <STRONG>tgoto</STRONG> or <STRONG>tparm</STRONG>, which both expand terminfo-
+ style strings as terminfo. (The <STRONG>tgoto</STRONG> function, if con-
+ figured to support termcap, will check if the string is
+ indeed terminfo-style by looking for "%p" parameters or
+ "$<..>" delays, and invoke a termcap-style parser if the
string does not appear to be terminfo).
- Because terminfo conventions for representing padding in
- string capabilities differ from termcap's, <STRONG>tputs("50");</STRONG>
- will put out a literal "50" rather than busy-waiting for
+ Because terminfo conventions for representing padding in
+ string capabilities differ from termcap's, <STRONG>tputs("50");</STRONG>
+ will put out a literal "50" rather than busy-waiting for
50 milliseconds. Cope with it.
- Note that termcap has nothing analogous to terminfo's <STRONG>sgr</STRONG>
- string. One consequence of this is that termcap applica-
- tions assume me (terminfo <STRONG>sgr0</STRONG>) does not reset the alter-
- nate character set. This implementation checks for, and
+ Note that termcap has nothing analogous to terminfo's <STRONG>sgr</STRONG>
+ string. One consequence of this is that termcap applica-
+ tions assume me (terminfo <STRONG>sgr0</STRONG>) does not reset the alter-
+ nate character set. This implementation checks for, and
modifies the data shown to the termcap interface to accom-
modate termcap's limitation in this respect.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- The XSI Curses standard, Issue 4 describes these func-
- tions. However, they are marked TO BE WITHDRAWN and may
+ The XSI Curses standard, Issue 4 describes these func-
+ tions. However, they are marked TO BE WITHDRAWN and may
be removed in future versions.
- Neither the XSI Curses standard nor the SVr4 man pages
- documented the return values of <STRONG>tgetent</STRONG> correctly, though
- all three were in fact returned ever since SVr1. In par-
- ticular, an omission in the XSI Curses documentation has
- been misinterpreted to mean that <STRONG>tgetent</STRONG> returns <STRONG>OK</STRONG> or
+ Neither the XSI Curses standard nor the SVr4 man pages
+ documented the return values of <STRONG>tgetent</STRONG> correctly, though
+ all three were in fact returned ever since SVr1. In par-
+ ticular, an omission in the XSI Curses documentation has
+ been misinterpreted to mean that <STRONG>tgetent</STRONG> returns <STRONG>OK</STRONG> or
<STRONG>ERR</STRONG>. Because the purpose of these functions is to provide
- compatibility with the <EM>termcap</EM> library, that is a defect
+ compatibility with the <EM>termcap</EM> library, that is a defect
in XCurses, Issue 4, Version 2 rather than in ncurses.
- External variables are provided for support of certain
- termcap applications. However, termcap applications' use
+ External variables are provided for support of certain
+ termcap applications. However, termcap applications' use
of those variables is poorly documented, e.g., not distin-
- guishing between input and output. In particular, some
+ guishing between input and output. In particular, some
applications are reported to declare and/or modify <STRONG>ospeed</STRONG>.
- The comment that only the first two characters of the <STRONG>id</STRONG>
- parameter are used escapes many application developers.
- The original BSD 4.2 termcap library (and historical
+ The comment that only the first two characters of the <STRONG>id</STRONG>
+ 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 <STRONG>tgetstr</STRONG>, <STRONG>tgetnum</STRONG> and <STRONG>tgetflag</STRONG>.
- Some applications assume that the termcap interface does
+ parameter name passed to <STRONG>tgetstr</STRONG>, <STRONG>tgetnum</STRONG> and <STRONG>tgetflag</STRONG>.
+ Some applications assume that the termcap interface does
not require the trailing NUL for the parameter name. Tak-
ing into account these issues:
- <STRONG>o</STRONG> As a special case, <STRONG>tgetflag</STRONG> matched against a single-
- character identifier provided that was at the end of
- the terminal description. You should not rely upon
- this behavior in portable programs. This implementa-
- tion disallows matches against single-character capa-
+ <STRONG>o</STRONG> As a special case, <STRONG>tgetflag</STRONG> matched against a single-
+ character identifier provided that was at the end of
+ the terminal description. You should not rely upon
+ this behavior in portable programs. This implementa-
+ tion disallows matches against single-character capa-
bility names.
- <STRONG>o</STRONG> This implementation disallows matches by the termcap
- interface against extended capability names which are
+ <STRONG>o</STRONG> This implementation disallows matches by the termcap
+ interface against extended capability names which are
longer than two characters.
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