<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<!--
****************************************************************************
* Copyright (c) 1998-2008,2010 Free Software Foundation, Inc. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the *
* "Software"), to deal in the Software without restriction, including *
* without limitation the rights to use, copy, modify, merge, publish, *
* distribute, distribute with modifications, sublicense, and/or sell *
* copies of the Software, and to permit persons to whom the Software is *
* furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included *
* in all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
* IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
* THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
* *
* Except as contained in this notice, the name(s) of the above copyright *
* holders shall not be used in advertising or otherwise to promote the *
* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************
* @Id: curs_util.3x,v 1.32 2010/12/04 18:38:55 tom Exp @
-->
<HTML>
<HEAD>
<TITLE>curs_util 3x</TITLE>
<link rev=made href="mailto:bug-ncurses@gnu.org">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</HEAD>
<BODY>
<H1>curs_util 3x</H1>
<HR>
<PRE>
<!-- Manpage converted by man2html 3.0.1 -->
<STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG> <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
</PRE>
<H2>NAME</H2><PRE>
<STRONG>delay_output</STRONG>, <STRONG>filter</STRONG>, <STRONG>flushinp</STRONG>, <STRONG>getwin</STRONG>, <STRONG>key_name</STRONG>, <STRONG>keyname</STRONG>,
<STRONG>nofilter</STRONG>, <STRONG>putwin</STRONG>, <STRONG>unctrl</STRONG>, <STRONG>use_env</STRONG>, <STRONG>wunctrl</STRONG> - miscellaneous
<STRONG>curses</STRONG> utility routines
</PRE>
<H2>SYNOPSIS</H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>char</STRONG> <STRONG>*unctrl(chtype</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>
<STRONG>void</STRONG> <STRONG>nofilter(void);</STRONG>
<STRONG>void</STRONG> <STRONG>use_env(bool</STRONG> <STRONG>f);</STRONG>
<STRONG>int</STRONG> <STRONG>putwin(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>FILE</STRONG> <STRONG>*filep);</STRONG>
<STRONG>WINDOW</STRONG> <STRONG>*getwin(FILE</STRONG> <STRONG>*filep);</STRONG>
<STRONG>int</STRONG> <STRONG>delay_output(int</STRONG> <STRONG>ms);</STRONG>
<STRONG>int</STRONG> <STRONG>flushinp(void);</STRONG>
</PRE>
<H2>DESCRIPTION</H2><PRE>
The <STRONG>unctrl</STRONG> routine returns a character string which is a
printable representation of the character <EM>c</EM>, ignoring at-
tributes. Control characters are displayed in the <STRONG>^</STRONG><EM>X</EM> no-
tation. Printing characters are displayed as is. The
corresponding <STRONG>wunctrl</STRONG> returns a printable representation
of a wide character.
The <STRONG>keyname</STRONG> routine returns a character string correspond-
ing to the key <EM>c</EM>:
<STRONG>o</STRONG> Printable characters are displayed as themselves,
e.g., a one-character string containing the key.
<STRONG>o</STRONG> Control characters are displayed in the <STRONG>^</STRONG><EM>X</EM> nota-
tion.
<STRONG>o</STRONG> DEL (character 127) is displayed as <STRONG>^?</STRONG>.
<STRONG>o</STRONG> Values above 128 are either meta characters (if the
screen has not been initialized, or if <STRONG>meta</STRONG> has
been called with a TRUE parameter), shown in the
<STRONG>M-</STRONG><EM>X</EM> notation, or are displayed as themselves. In
the latter case, the values may not be printable;
this follows the X/Open specification.
<STRONG>o</STRONG> Values above 256 may be the names of the names of
function keys.
<STRONG>o</STRONG> Otherwise (if there is no corresponding name) the
function returns null, to denote an error. X/Open
also lists an "UNKNOWN KEY" return value, which
some implementations return rather than null.
The corresponding <STRONG>key_name</STRONG> returns a character string cor-
responding to the wide-character value <EM>w</EM>. The two func-
tions do not return the same set of strings; the latter
returns null where the former would display a meta charac-
ter.
The <STRONG>filter</STRONG> routine, if used, must be called before <STRONG>initscr</STRONG>
or <STRONG>newterm</STRONG> are called. The effect is that, during those
calls, <STRONG>LINES</STRONG> is set to 1; the capabilities <STRONG>clear</STRONG>, <STRONG>cup</STRONG>,
<STRONG>cud</STRONG>, <STRONG>cud1</STRONG>, <STRONG>cuu1</STRONG>, <STRONG>cuu</STRONG>, <STRONG>vpa</STRONG> are disabled; and the <STRONG>home</STRONG>
string is set to the value of <STRONG>cr</STRONG>.
The <STRONG>nofilter</STRONG> routine cancels the effect of a preceding
<STRONG>filter</STRONG> call. That allows the caller to initialize a
screen on a different device, using a different value of
<STRONG>$TERM</STRONG>. The limitation arises because the <STRONG>filter</STRONG> routine
modifies the in-memory copy of the terminal information.
The <STRONG>use_env</STRONG> routine, if used, is called before <STRONG>initscr</STRONG> or
<STRONG>newterm</STRONG> are called. When called with <STRONG>FALSE</STRONG> as an argu-
ment, the values of <STRONG>lines</STRONG> and <STRONG>columns</STRONG> specified in the
<EM>terminfo</EM> database will be used, even if environment vari-
ables <STRONG>LINES</STRONG> and <STRONG>COLUMNS</STRONG> (used by default) are set, or if
<STRONG>curses</STRONG> is running in a window (in which case default be-
havior would be to use the window size if <STRONG>LINES</STRONG> and
<STRONG>COLUMNS</STRONG> are not set). Note that setting <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG>
overrides the corresponding size which may be obtained
from the operating system.
The <STRONG>putwin</STRONG> routine writes all data associated with window
<EM>win</EM> into the file to which <EM>filep</EM> points. This information
can be later retrieved using the <STRONG>getwin</STRONG> function.
The <STRONG>getwin</STRONG> routine reads window related data stored in the
file by <STRONG>putwin</STRONG>. The routine then creates and initializes
a new window using that data. It returns a pointer to the
new window.
The <STRONG>delay_output</STRONG> routine inserts an <EM>ms</EM> millisecond pause
in output. This routine should not be used extensively
because padding characters are used rather than a CPU
pause. If no padding character is specified, this uses
<STRONG>napms</STRONG> to perform the delay.
The <STRONG>flushinp</STRONG> routine throws away any typeahead that has
been typed by the user and has not yet been read by the
program.
</PRE>
<H2>RETURN VALUE</H2><PRE>
Except for <STRONG>flushinp</STRONG>, routines that return an integer re-
turn <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> (SVr4 specifies only "an in-
teger value other than <STRONG>ERR</STRONG>") upon successful completion.
Routines that return pointers return <STRONG>NULL</STRONG> on error.
X/Open does not define any error conditions. In this im-
plementation
<STRONG>flushinp</STRONG>
returns an error if the terminal was not initial-
ized.
<STRONG>meta</STRONG> returns an error if the terminal was not initial-
ized.
<STRONG>putwin</STRONG>
returns an error if the associated <STRONG>fwrite</STRONG> calls
return an error.
</PRE>
<H2>PORTABILITY</H2><PRE>
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. This implementation checks for three cas-
es:
<STRONG>o</STRONG> the parameter is a 7-bit US-ASCII code. This is
the case that X/Open Curses documented.
<STRONG>o</STRONG> 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 con-
trols.
X/Open Curses does not document whether <STRONG>unctrl</STRONG> can
be called before initializing curses. This imple-
mentation permits that, and returns the ``~@'',
etc., values in that case.
<STRONG>o</STRONG> parameter values outside the 0 to 255 range. <STRONG>unc-</STRONG>
<STRONG>trl</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
from the XSI Curses standard (which erroneously fails to
describe the disabling of <STRONG>cuu</STRONG>).
The strings returned by <STRONG>unctrl</STRONG> in this implementation are
determined at compile time, showing C1 controls from the
upper-128 codes with a `~' prefix rather than `^'. Other
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-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-
matically assigns at run-time keycodes to user-defined
strings which begin with "k". The keycodes start at
KEY_MAX, but are not guaranteed to be the same value for
different runs because user-defined codes are merged from
all terminal descriptions which have been loaded. The
<STRONG>use_extended_names</STRONG> function controls whether this data is
loaded when the terminal description is read by the li-
brary.
The <STRONG>nofilter</STRONG> routine is specific to ncurses. It was not
supported on Version 7, BSD or System V implementations.
It is recommended that any code depending on ncurses ex-
tensions be conditioned using NCURSES_VERSION.
</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_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG>lega-</STRONG>
<STRONG><A HREF="legacy_coding.3x.html">cy_coding(3x)</A></STRONG>.
<STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
</PRE>
<HR>
<ADDRESS>
Man(1) output converted with
<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
</ADDRESS>
</BODY>
</HTML>
