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- * @Id: curs_util.3x,v 1.22 2006/12/24 14:55:31 tom Exp @
+ * @Id: curs_util.3x,v 1.25 2007/05/26 21:44:42 tom Exp @
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<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>char</STRONG> <STRONG>*unctrl(chtype</STRONG> <STRONG>c);</STRONG>
- <STRONG>char</STRONG> <STRONG>*wunctrl(cchar_t</STRONG> <STRONG>*c);</STRONG>
+ <STRONG>wchar_t</STRONG> <STRONG>*wunctrl(cchar_t</STRONG> <STRONG>*c);</STRONG>
<STRONG>char</STRONG> <STRONG>*keyname(int</STRONG> <STRONG>c);</STRONG>
<STRONG>char</STRONG> <STRONG>*key_name(wchar_t</STRONG> <STRONG>w);</STRONG>
<STRONG>void</STRONG> <STRONG>filter(void);</STRONG>
The XSI Curses standard, Issue 4 describes these func-
tions. It states that <STRONG>unctrl</STRONG> and <STRONG>wunctrl</STRONG> will return a
null pointer if unsuccessful, but does not define any er-
- ror conditions.
+ ror conditions. This implementation checks for three cas-
+ es:
+
+ - the parameter is a 7-bit US-ASCII code. This
+ is the case that X/Open Curses documented.
+
+ - the parameter is in the range 128-159, i.e., a
+ C1 control code. If <STRONG>use_legacy_coding</STRONG> has
+ been called with a <STRONG>2</STRONG> parameter, <STRONG>unctrl</STRONG> returns
+ the parameter, i.e., a one-character string
+ with the parameter as the first character.
+ Otherwise, it returns ``~@'', ``~A'', etc.,
+ analogous to ``^@'', ``^A'', C0 controls.
+
+ X/Open Curses does not document whether <STRONG>unctrl</STRONG>
+ can be called before initializing curses.
+ This implementation permits that, and returns
+ the ``~@'', etc., values in that case.
+
+ - parameter values outside the 0 to 255 range.
+ <STRONG>unctrl</STRONG> returns a null pointer.
The SVr4 documentation describes the action of <STRONG>filter</STRONG> only
in the vaguest terms. The description here is adapted
implementations have different conventions. For example,
they may show both sets of control characters with `^',
and strip the parameter to 7 bits. Or they may ignore C1
- controls and treat all of the upper-1280 codes as print-
+ controls and treat all of the upper-128 codes as print-
able. This implementation uses 8 bits but does not modify
the string to reflect locale. The <STRONG>use_legacy_coding</STRONG> func-
tion allows the caller to change the output of <STRONG>unctrl</STRONG>.
+ Likewise, the <STRONG>meta</STRONG> function allows the caller to change
+ the output of <STRONG>keyname</STRONG>, i.e., it determines whether to use
+ the `M-' prefix for ``meta'' keys (codes in the range 128
+ to 255). Both <STRONG>use_legacy_coding</STRONG> and <STRONG>meta</STRONG> succeed only af-
+ ter curses is initialized. X/Open Curses does not docu-
+ ment the treatment of codes 128 to 159. When treating
+ them as ``meta'' keys (or if <STRONG>keyname</STRONG> is called before ini-
+ tializing curses), this implementation returns strings
+ ``M-^@'', ``M-^A'', etc.
+
The <STRONG>keyname</STRONG> function may return the names of user-defined
string capabilities which are defined in the terminfo en-
try via the <STRONG>-x</STRONG> option of <STRONG>tic</STRONG>. This implementation auto-
</PRE>
<H2>SEE ALSO</H2><PRE>
<STRONG><A HREF="legacy_coding.3x.html">legacy_coding(3x)</A></STRONG>, <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG>curs_ker-</STRONG>
- <STRONG><A HREF="curs_kernel.3x.html">nel(3x)</A></STRONG>, <STRONG><A HREF="curs_scr_dump.3x.html">curs_scr_dump(3x)</A></STRONG>.
+ <STRONG><A HREF="curs_kernel.3x.html">nel(3x)</A></STRONG>, <STRONG><A HREF="curs_scr_dump.3x.html">curs_scr_dump(3x)</A></STRONG>, <STRONG><A HREF="legacy_coding.3x.html">legacy_coding(3x)</A></STRONG>.
projects / ncurses.git / blobdiff