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30 * @Id: curs_util.3x,v 1.46 2017/01/07 19:35:54 tom Exp @
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42 <H1 class="no-header">curs_util 3x</H1>
44 <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG> <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50 <STRONG>delay_output</STRONG>, <STRONG>filter</STRONG>, <STRONG>flushinp</STRONG>, <STRONG>getwin</STRONG>, <STRONG>key_name</STRONG>, <STRONG>keyname</STRONG>,
51 <STRONG>nofilter</STRONG>, <STRONG>putwin</STRONG>, <STRONG>unctrl</STRONG>, <STRONG>use_env</STRONG>, <STRONG>use_tioctl</STRONG>, <STRONG>wunctrl</STRONG> -
52 miscellaneous <STRONG>curses</STRONG> utility routines
55 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
56 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
58 <STRONG>char</STRONG> <STRONG>*unctrl(chtype</STRONG> <STRONG>c);</STRONG>
59 <STRONG>wchar_t</STRONG> <STRONG>*wunctrl(cchar_t</STRONG> <STRONG>*c);</STRONG>
60 <STRONG>char</STRONG> <STRONG>*keyname(int</STRONG> <STRONG>c);</STRONG>
61 <STRONG>char</STRONG> <STRONG>*key_name(wchar_t</STRONG> <STRONG>w);</STRONG>
62 <STRONG>void</STRONG> <STRONG>filter(void);</STRONG>
63 <STRONG>void</STRONG> <STRONG>nofilter(void);</STRONG>
64 <STRONG>void</STRONG> <STRONG>use_env(bool</STRONG> <STRONG>f);</STRONG>
65 <STRONG>void</STRONG> <STRONG>use_tioctl(bool</STRONG> <STRONG>f);</STRONG>
66 <STRONG>int</STRONG> <STRONG>putwin(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>FILE</STRONG> <STRONG>*filep);</STRONG>
67 <STRONG>WINDOW</STRONG> <STRONG>*getwin(FILE</STRONG> <STRONG>*filep);</STRONG>
68 <STRONG>int</STRONG> <STRONG>delay_output(int</STRONG> <STRONG>ms);</STRONG>
69 <STRONG>int</STRONG> <STRONG>flushinp(void);</STRONG>
72 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
74 </PRE><H3><a name="h3-unctrl">unctrl</a></H3><PRE>
75 The <STRONG>unctrl</STRONG> routine returns a character string which is a
76 printable representation of the character <EM>c</EM>, ignoring at-
77 tributes. Control characters are displayed in the <STRONG>^</STRONG><EM>X</EM> no-
78 tation. Printing characters are displayed as is. The
79 corresponding <STRONG>wunctrl</STRONG> returns a printable representation
83 </PRE><H3><a name="h3-keyname_key_name">keyname/key_name</a></H3><PRE>
84 The <STRONG>keyname</STRONG> routine returns a character string correspond-
85 ing to the key <EM>c</EM>:
87 <STRONG>o</STRONG> Printable characters are displayed as themselves,
88 e.g., a one-character string containing the key.
90 <STRONG>o</STRONG> Control characters are displayed in the <STRONG>^</STRONG><EM>X</EM> notation.
92 <STRONG>o</STRONG> DEL (character 127) is displayed as <STRONG>^?</STRONG>.
94 <STRONG>o</STRONG> Values above 128 are either meta characters (if the
95 screen has not been initialized, or if <STRONG><A HREF="curs_inopts.3x.html">meta(3x)</A></STRONG> has
96 been called with a <STRONG>TRUE</STRONG> parameter), shown in the <STRONG>M-</STRONG><EM>X</EM>
97 notation, or are displayed as themselves. In the lat-
98 ter case, the values may not be printable; this fol-
99 lows the X/Open specification.
101 <STRONG>o</STRONG> Values above 256 may be the names of the names of
104 <STRONG>o</STRONG> Otherwise (if there is no corresponding name) the
105 function returns null, to denote an error. X/Open al-
106 so lists an "UNKNOWN KEY" return value, which some im-
107 plementations return rather than null.
109 The corresponding <STRONG>key_name</STRONG> returns a character string cor-
110 responding to the wide-character value <EM>w</EM>. The two func-
111 tions do not return the same set of strings; the latter
112 returns null where the former would display a meta charac-
116 </PRE><H3><a name="h3-filter_nofilter">filter/nofilter</a></H3><PRE>
117 The <STRONG>filter</STRONG> routine, if used, must be called before <STRONG>initscr</STRONG>
118 or <STRONG>newterm</STRONG> are called. The effect is that, during those
119 calls, <STRONG>LINES</STRONG> is set to 1; the capabilities <STRONG>clear</STRONG>, <STRONG>cup</STRONG>,
120 <STRONG>cud</STRONG>, <STRONG>cud1</STRONG>, <STRONG>cuu1</STRONG>, <STRONG>cuu</STRONG>, <STRONG>vpa</STRONG> are disabled; and the <STRONG>home</STRONG>
121 string is set to the value of <STRONG>cr</STRONG>.
123 The <STRONG>nofilter</STRONG> routine cancels the effect of a preceding
124 <STRONG>filter</STRONG> call. That allows the caller to initialize a
125 screen on a different device, using a different value of
126 <STRONG>$TERM</STRONG>. The limitation arises because the <STRONG>filter</STRONG> routine
127 modifies the in-memory copy of the terminal information.
130 </PRE><H3><a name="h3-use_env">use_env</a></H3><PRE>
131 The <STRONG>use_env</STRONG> routine, if used, should be called before
132 <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG> are called (because those compute the
133 screen size). It modifies the way <STRONG>ncurses</STRONG> treats environ-
134 ment variables when determining the screen size.
136 <STRONG>o</STRONG> Normally <STRONG>ncurses</STRONG> looks first at the terminal database
139 If <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> for parameter, it
140 stops here unless If <STRONG>use_tioctl</STRONG> was also called with
141 <STRONG>TRUE</STRONG> for parameter.
143 <STRONG>o</STRONG> Then it asks for the screen size via operating system
144 calls. If successful, it overrides the values from
145 the terminal database.
147 <STRONG>o</STRONG> Finally (unless <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> parame-
148 ter), <STRONG>ncurses</STRONG> examines the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG> environ-
149 ment variables, using a value in those to override the
150 results from the operating system or terminal data-
153 <STRONG>Ncurses</STRONG> also updates the screen size in response to
154 SIGWINCH, unless overridden by the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG>
155 environment variables,
158 </PRE><H3><a name="h3-use_tioctl">use_tioctl</a></H3><PRE>
159 The <STRONG>use_tioctl</STRONG> routine, if used, should be called before
160 <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG> are called (because those compute the
161 screen size). After <STRONG>use_tioctl</STRONG> is called with <STRONG>TRUE</STRONG> as an
162 argument, <STRONG>ncurses</STRONG> modifies the last step in its computa-
163 tion of screen size as follows:
165 <STRONG>o</STRONG> checks if the <STRONG>LINES</STRONG> and <STRONG>COLUMNS</STRONG> environment variables
166 are set to a number greater than zero.
168 <STRONG>o</STRONG> for each, <STRONG>ncurses</STRONG> updates the corresponding environ-
169 ment variable with the value that it has obtained via
170 operating system call or from the terminal database.
172 <STRONG>o</STRONG> <STRONG>ncurses</STRONG> re-fetches the value of the environment vari-
173 ables so that it is still the environment variables
174 which set the screen size.
176 The <STRONG>use_env</STRONG> and <STRONG>use_tioctl</STRONG> routines combine as summarized
179 <EM>use</EM><STRONG>_</STRONG><EM>env</EM> <EM>use</EM><STRONG>_</STRONG><EM>tioctl</EM> <EM>Summary</EM>
180 ----------------------------------------------------------------
184 TRUE FALSE This is the default behavior. <STRONG>ncurses</STRONG>
185 uses operating system calls unless over-
186 ridden by $LINES or $COLUMNS environment
188 TRUE TRUE <STRONG>ncurses</STRONG> updates $LINES and $COLUMNS
189 based on operating system calls.
190 FALSE TRUE <STRONG>ncurses</STRONG> ignores $LINES and $COLUMNS, us-
191 es operating system calls to obtain
193 FALSE FALSE <STRONG>ncurses</STRONG> relies on the terminal database
197 </PRE><H3><a name="h3-putwin_getwin">putwin/getwin</a></H3><PRE>
198 The <STRONG>putwin</STRONG> routine writes all data associated with window
199 (or pad) <EM>win</EM> into the file to which <EM>filep</EM> points. This
200 information can be later retrieved using the <STRONG>getwin</STRONG> func-
203 The <STRONG>getwin</STRONG> routine reads window related data stored in the
204 file by <STRONG>putwin</STRONG>. The routine then creates and initializes
205 a new window using that data. It returns a pointer to the
206 new window. There are a few caveats:
208 <STRONG>o</STRONG> the data written is a copy of the <STRONG>WINDOW</STRONG> structure,
209 and its associated character cells. The format dif-
210 fers between the wide-character (ncursesw) and non-
211 wide (ncurses) libraries. You can transfer data be-
212 tween the two, however.
214 <STRONG>o</STRONG> the retrieved window is always created as a top-level
215 window (or pad), rather than a subwindow.
217 <STRONG>o</STRONG> the window's character cells contain the color pair
218 <EM>value</EM>, but not the actual color <EM>numbers</EM>. If cells in
219 the retrieved window use color pairs which have not
220 been created in the application using <STRONG>init_pair</STRONG>, they
221 will not be colored when the window is refreshed.
224 </PRE><H3><a name="h3-delay_output">delay_output</a></H3><PRE>
225 The <STRONG>delay_output</STRONG> routine inserts an <EM>ms</EM> millisecond pause
226 in output. This routine should not be used extensively
227 because padding characters are used rather than a CPU
228 pause. If no padding character is specified, this uses
229 <STRONG>napms</STRONG> to perform the delay.
232 </PRE><H3><a name="h3-flushinp">flushinp</a></H3><PRE>
233 The <STRONG>flushinp</STRONG> routine throws away any typeahead that has
234 been typed by the user and has not yet been read by the
238 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
239 Except for <STRONG>flushinp</STRONG>, routines that return an integer re-
240 turn <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> (SVr4 specifies only "an in-
241 teger value other than <STRONG>ERR</STRONG>") upon successful completion.
243 Routines that return pointers return <STRONG>NULL</STRONG> on error.
245 X/Open does not define any error conditions. In this im-
248 <STRONG>flushinp</STRONG>
249 returns an error if the terminal was not initial-
252 <STRONG>putwin</STRONG>
253 returns an error if the associated <STRONG>fwrite</STRONG> calls
257 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
259 </PRE><H3><a name="h3-filter">filter</a></H3><PRE>
260 The SVr4 documentation describes the action of <STRONG>filter</STRONG> only
261 in the vaguest terms. The description here is adapted
262 from the XSI Curses standard (which erroneously fails to
263 describe the disabling of <STRONG>cuu</STRONG>).
266 </PRE><H3><a name="h3-keyname">keyname</a></H3><PRE>
267 The <STRONG>keyname</STRONG> function may return the names of user-defined
268 string capabilities which are defined in the terminfo en-
269 try via the <STRONG>-x</STRONG> option of <STRONG>tic</STRONG>. This implementation auto-
270 matically assigns at run-time keycodes to user-defined
271 strings which begin with "k". The keycodes start at
272 KEY_MAX, but are not guaranteed to be the same value for
273 different runs because user-defined codes are merged from
274 all terminal descriptions which have been loaded. The
275 <STRONG>use_extended_names</STRONG> function controls whether this data is
276 loaded when the terminal description is read by the li-
280 </PRE><H3><a name="h3-nofilter_use_tioctl">nofilter/use_tioctl</a></H3><PRE>
281 The <STRONG>nofilter</STRONG> and <STRONG>use_tioctl</STRONG> routines are specific to
282 <STRONG>ncurses</STRONG>. They were not supported on Version 7, BSD or
283 System V implementations. It is recommended that any code
284 depending on <STRONG>ncurses</STRONG> extensions be conditioned using
288 </PRE><H3><a name="h3-putwin_getwin">putwin/getwin</a></H3><PRE>
289 The <STRONG>putwin</STRONG> and <STRONG>getwin</STRONG> functions have several issues with
292 <STRONG>o</STRONG> The files written and read by these functions use an
293 implementation-specific format. Although the format
294 is an obvious target for standardization, it has been
297 Interestingly enough, according to the copyright dates
298 in Solaris source, the functions (along with <STRONG>scr_init</STRONG>,
299 etc.) originated with the University of California,
300 Berkeley (in 1982) and were later (in 1988) incorpo-
301 rated into SVr4. Oddly, there are no such functions
302 in the 4.3BSD curses sources.
304 <STRONG>o</STRONG> Most implementations simply dump the binary <STRONG>WINDOW</STRONG>
305 structure to the file. These include SVr4 curses,
306 NetBSD and PDCurses, as well as older <STRONG>ncurses</STRONG> ver-
307 sions. This implementation (as well as the X/Open
308 variant of Solaris curses, dated 1995) uses textual
311 The implementations which use binary dumps use block-
312 I/O (the <STRONG>fwrite</STRONG> and <STRONG>fread</STRONG> functions). Those that use
313 textual dumps use buffered-I/O. A few applications
314 may happen to write extra data in the file using these
315 functions. Doing that can run into problems mixing
316 block- and buffered-I/O. This implementation reduces
317 the problem on writes by flushing the output. Howev-
318 er, reading from a file written using mixed schemes
319 may not be successful.
322 </PRE><H3><a name="h3-unctrl_wunctrl">unctrl/wunctrl</a></H3><PRE>
323 The XSI Curses standard, Issue 4 describes these func-
324 tions. It states that <STRONG>unctrl</STRONG> and <STRONG>wunctrl</STRONG> will return a
325 null pointer if unsuccessful, but does not define any er-
326 ror conditions. This implementation checks for three cas-
329 <STRONG>o</STRONG> the parameter is a 7-bit US-ASCII code. This is the
330 case that X/Open Curses documented.
332 <STRONG>o</STRONG> the parameter is in the range 128-159, i.e., a C1 con-
333 trol code. If <STRONG>use_legacy_coding</STRONG> has been called with
334 a <STRONG>2</STRONG> parameter, <STRONG>unctrl</STRONG> returns the parameter, i.e., a
335 one-character string with the parameter as the first
336 character. Otherwise, it returns "~@", "~A", etc.,
337 analogous to "^@", "^A", C0 controls.
339 X/Open Curses does not document whether <STRONG>unctrl</STRONG> can be
340 called before initializing curses. This implementa-
341 tion permits that, and returns the "~@", etc., values
344 <STRONG>o</STRONG> parameter values outside the 0 to 255 range. <STRONG>unctrl</STRONG>
345 returns a null pointer.
347 The strings returned by <STRONG>unctrl</STRONG> in this implementation are
348 determined at compile time, showing C1 controls from the
349 upper-128 codes with a `~' prefix rather than `^'. Other
350 implementations have different conventions. For example,
351 they may show both sets of control characters with `^',
352 and strip the parameter to 7 bits. Or they may ignore C1
353 controls and treat all of the upper-128 codes as print-
354 able. This implementation uses 8 bits but does not modify
355 the string to reflect locale. The <STRONG>use_legacy_coding</STRONG> func-
356 tion allows the caller to change the output of <STRONG>unctrl</STRONG>.
358 Likewise, the <STRONG><A HREF="curs_inopts.3x.html">meta(3x)</A></STRONG> function allows the caller to
359 change the output of <STRONG>keyname</STRONG>, i.e., it determines whether
360 to use the `M-' prefix for "meta" keys (codes in the range
361 128 to 255). Both <STRONG>use_legacy_coding</STRONG> and <STRONG>meta</STRONG> succeed only
362 after curses is initialized. X/Open Curses does not docu-
363 ment the treatment of codes 128 to 159. When treating
364 them as "meta" keys (or if <STRONG>keyname</STRONG> is called before ini-
365 tializing curses), this implementation returns strings
369 </PRE><H3><a name="h3-use_env_use_tioctl">use_env/use_tioctl</a></H3><PRE>
370 If <STRONG>ncurses</STRONG> is configured to provide the sp-functions ex-
371 tension, the state of <STRONG>use_env</STRONG> and <STRONG>use_tioctl</STRONG> may be updat-
372 ed before creating each <EM>screen</EM> rather than once only
373 (<STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG>). This feature of <STRONG>use_env</STRONG> is not pro-
374 vided by other implementation of curses.
377 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
378 <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_in-</STRONG>
379 <STRONG><A HREF="curs_inopts.3x.html">opts(3x)</A></STRONG>, <STRONG><A HREF="curs_kernel.3x.html">curs_kernel(3x)</A></STRONG>, <STRONG><A HREF="curs_scr_dump.3x.html">curs_scr_dump(3x)</A></STRONG>,
380 <STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG><A HREF="legacy_coding.3x.html">legacy_coding(3x)</A></STRONG>.
384 <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
388 <li><a href="#h2-NAME">NAME</a></li>
389 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
390 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
392 <li><a href="#h3-unctrl">unctrl</a></li>
393 <li><a href="#h3-keyname_key_name">keyname/key_name</a></li>
394 <li><a href="#h3-filter_nofilter">filter/nofilter</a></li>
395 <li><a href="#h3-use_env">use_env</a></li>
396 <li><a href="#h3-use_tioctl">use_tioctl</a></li>
397 <li><a href="#h3-putwin_getwin">putwin/getwin</a></li>
398 <li><a href="#h3-delay_output">delay_output</a></li>
399 <li><a href="#h3-flushinp">flushinp</a></li>
402 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
403 <li><a href="#h2-PORTABILITY">PORTABILITY</a>
405 <li><a href="#h3-filter">filter</a></li>
406 <li><a href="#h3-keyname">keyname</a></li>
407 <li><a href="#h3-nofilter_use_tioctl">nofilter/use_tioctl</a></li>
408 <li><a href="#h3-putwin_getwin">putwin/getwin</a></li>
409 <li><a href="#h3-unctrl_wunctrl">unctrl/wunctrl</a></li>
410 <li><a href="#h3-use_env_use_tioctl">use_env/use_tioctl</a></li>
413 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>