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30 * @Id: curs_util.3x,v 1.52 2017/11/18 23:47:37 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>, <STRONG>nofilter</STRONG>,
51 <STRONG>putwin</STRONG>, <STRONG>unctrl</STRONG>, <STRONG>use_env</STRONG>, <STRONG>use_tioctl</STRONG>, <STRONG>wunctrl</STRONG> - miscellaneous <STRONG>curses</STRONG>
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 printable rep-
76 resentation of the character <EM>c</EM>, ignoring attributes. Control charac-
77 ters are displayed in the <STRONG>^</STRONG><EM>X</EM> notation. Printing characters are dis-
78 played as is. The corresponding <STRONG>wunctrl</STRONG> returns a printable represen-
79 tation of a wide character.
82 </PRE><H3><a name="h3-keyname_key_name">keyname/key_name</a></H3><PRE>
83 The <STRONG>keyname</STRONG> routine returns a character string corresponding to the key
86 <STRONG>o</STRONG> Printable characters are displayed as themselves, e.g., a one-char-
87 acter string containing the key.
89 <STRONG>o</STRONG> Control characters are displayed in the <STRONG>^</STRONG><EM>X</EM> notation.
91 <STRONG>o</STRONG> DEL (character 127) is displayed as <STRONG>^?</STRONG>.
93 <STRONG>o</STRONG> Values above 128 are either meta characters (if the screen has not
94 been initialized, or if <STRONG><A HREF="curs_inopts.3x.html">meta(3x)</A></STRONG> has been called with a <STRONG>TRUE</STRONG> param-
95 eter), shown in the <STRONG>M-</STRONG><EM>X</EM> notation, or are displayed as themselves.
96 In the latter case, the values may not be printable; this follows
97 the X/Open specification.
99 <STRONG>o</STRONG> Values above 256 may be the names of the names of function keys.
101 <STRONG>o</STRONG> Otherwise (if there is no corresponding name) the function returns
102 null, to denote an error. X/Open also lists an "UNKNOWN KEY" re-
103 turn value, which some implementations return rather than null.
105 The corresponding <STRONG>key_name</STRONG> returns a character string corresponding to
106 the wide-character value <EM>w</EM>. The two functions do not return the same
107 set of strings; the latter returns null where the former would display
111 </PRE><H3><a name="h3-filter_nofilter">filter/nofilter</a></H3><PRE>
112 The <STRONG>filter</STRONG> routine, if used, must be called before <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG>
113 are called. Calling <STRONG>filter</STRONG> causes these changes in initialization:
115 <STRONG>o</STRONG> <STRONG>LINES</STRONG> is set to 1;
117 <STRONG>o</STRONG> the capabilities <STRONG>clear</STRONG>, <STRONG>cud1</STRONG>, <STRONG>cud</STRONG>, <STRONG>cup</STRONG>, <STRONG>cuu1</STRONG>, <STRONG>cuu</STRONG>, <STRONG>vpa</STRONG> are dis-
120 <STRONG>o</STRONG> the capability <STRONG>ed</STRONG> is disabled if <STRONG>bce</STRONG> is set;
122 <STRONG>o</STRONG> and the <STRONG>home</STRONG> string is set to the value of <STRONG>cr</STRONG>.
124 The <STRONG>nofilter</STRONG> routine cancels the effect of a preceding <STRONG>filter</STRONG> call.
125 That allows the caller to initialize a screen on a different device,
126 using a different value of <STRONG>$TERM</STRONG>. The limitation arises because the
127 <STRONG>filter</STRONG> routine 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 <STRONG>initscr</STRONG> or
132 <STRONG>newterm</STRONG> are called (because those compute the screen size). It modi-
133 fies the way <STRONG>ncurses</STRONG> treats environment variables when determining the
136 <STRONG>o</STRONG> Normally <STRONG>ncurses</STRONG> looks first at the terminal database for the
139 If <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> for parameter, it stops here un-
140 less <STRONG>use_tioctl</STRONG> was also called with <STRONG>TRUE</STRONG> for parameter.
142 <STRONG>o</STRONG> Then it asks for the screen size via operating system calls. If
143 successful, it overrides the values from the terminal database.
145 <STRONG>o</STRONG> Finally (unless <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> parameter), <STRONG>ncurses</STRONG>
146 examines the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG> environment variables, using a value
147 in those to override the results from the operating system or ter-
150 <STRONG>Ncurses</STRONG> also updates the screen size in response to <STRONG>SIGWINCH</STRONG>, un-
151 less overridden by the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG> environment variables,
154 </PRE><H3><a name="h3-use_tioctl">use_tioctl</a></H3><PRE>
155 The <STRONG>use_tioctl</STRONG> routine, if used, should be called before <STRONG>initscr</STRONG> or
156 <STRONG>newterm</STRONG> are called (because those compute the screen size). After
157 <STRONG>use_tioctl</STRONG> is called with <STRONG>TRUE</STRONG> as an argument, <STRONG>ncurses</STRONG> modifies the
158 last step in its computation of screen size as follows:
160 <STRONG>o</STRONG> checks if the <STRONG>LINES</STRONG> and <STRONG>COLUMNS</STRONG> environment variables are set to a
161 number greater than zero.
163 <STRONG>o</STRONG> for each, <STRONG>ncurses</STRONG> updates the corresponding environment variable
164 with the value that it has obtained via operating system call or
165 from the terminal database.
167 <STRONG>o</STRONG> <STRONG>ncurses</STRONG> re-fetches the value of the environment variables so that
168 it is still the environment variables which set the screen size.
170 The <STRONG>use_env</STRONG> and <STRONG>use_tioctl</STRONG> routines combine as summarized here:
172 <EM>use</EM><STRONG>_</STRONG><EM>env</EM> <EM>use</EM><STRONG>_</STRONG><EM>tioctl</EM> <EM>Summary</EM>
173 ----------------------------------------------------------------
174 TRUE FALSE This is the default behavior. <STRONG>ncurses</STRONG>
175 uses operating system calls unless over-
176 ridden by $LINES or $COLUMNS environment
178 TRUE TRUE <STRONG>ncurses</STRONG> updates $LINES and $COLUMNS
179 based on operating system calls.
180 FALSE TRUE <STRONG>ncurses</STRONG> ignores $LINES and $COLUMNS, us-
181 es operating system calls to obtain
183 FALSE FALSE <STRONG>ncurses</STRONG> relies on the terminal database
187 </PRE><H3><a name="h3-putwin_getwin">putwin/getwin</a></H3><PRE>
188 The <STRONG>putwin</STRONG> routine writes all data associated with window (or pad) <EM>win</EM>
189 into the file to which <EM>filep</EM> points. This information can be later re-
190 trieved using the <STRONG>getwin</STRONG> function.
192 The <STRONG>getwin</STRONG> routine reads window related data stored in the file by
193 <STRONG>putwin</STRONG>. The routine then creates and initializes a new window using
194 that data. It returns a pointer to the new window. There are a few
197 <STRONG>o</STRONG> the data written is a copy of the <STRONG>WINDOW</STRONG> structure, and its associ-
198 ated character cells. The format differs between the wide-charac-
199 ter (ncursesw) and non-wide (ncurses) libraries. You can transfer
200 data between the two, however.
202 <STRONG>o</STRONG> the retrieved window is always created as a top-level window (or
203 pad), rather than a subwindow.
205 <STRONG>o</STRONG> the window's character cells contain the color pair <EM>value</EM>, but not
206 the actual color <EM>numbers</EM>. If cells in the retrieved window use
207 color pairs which have not been created in the application using
208 <STRONG>init_pair</STRONG>, they will not be colored when the window is refreshed.
211 </PRE><H3><a name="h3-delay_output">delay_output</a></H3><PRE>
212 The <STRONG>delay_output</STRONG> routine inserts an <EM>ms</EM> millisecond pause in output.
213 This routine should not be used extensively because padding characters
214 are used rather than a CPU pause. If no padding character is speci-
215 fied, this uses <STRONG>napms</STRONG> to perform the delay.
218 </PRE><H3><a name="h3-flushinp">flushinp</a></H3><PRE>
219 The <STRONG>flushinp</STRONG> routine throws away any typeahead that has been typed by
220 the user and has not yet been read by the program.
223 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
224 Except for <STRONG>flushinp</STRONG>, routines that return an integer return <STRONG>ERR</STRONG> upon
225 failure and <STRONG>OK</STRONG> (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>")
226 upon successful completion.
228 Routines that return pointers return <STRONG>NULL</STRONG> on error.
230 X/Open does not define any error conditions. In this implementation
232 <STRONG>flushinp</STRONG>
233 returns an error if the terminal was not initialized.
235 <STRONG>putwin</STRONG>
236 returns an error if the associated <STRONG>fwrite</STRONG> calls return an er-
240 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
242 </PRE><H3><a name="h3-filter">filter</a></H3><PRE>
243 The SVr4 documentation describes the action of <STRONG>filter</STRONG> only in the
244 vaguest terms. The description here is adapted from the XSI Curses
245 standard (which erroneously fails to describe the disabling of <STRONG>cuu</STRONG>).
248 </PRE><H3><a name="h3-keyname">keyname</a></H3><PRE>
249 The <STRONG>keyname</STRONG> function may return the names of user-defined string capa-
250 bilities which are defined in the terminfo entry via the <STRONG>-x</STRONG> option of
251 <STRONG>tic</STRONG>. This implementation automatically assigns at run-time keycodes to
252 user-defined strings which begin with "k". The keycodes start at
253 KEY_MAX, but are not guaranteed to be the same value for different runs
254 because user-defined codes are merged from all terminal descriptions
255 which have been loaded. The <STRONG><A HREF="curs_extend.3x.html">use_extended_names(3x)</A></STRONG> function controls
256 whether this data is loaded when the terminal description is read by
260 </PRE><H3><a name="h3-nofilter_use_tioctl">nofilter/use_tioctl</a></H3><PRE>
261 The <STRONG>nofilter</STRONG> and <STRONG>use_tioctl</STRONG> routines are specific to <STRONG>ncurses</STRONG>. They
262 were not supported on Version 7, BSD or System V implementations. It
263 is recommended that any code depending on <STRONG>ncurses</STRONG> extensions be condi-
264 tioned using NCURSES_VERSION.
267 </PRE><H3><a name="h3-putwin_getwin">putwin/getwin</a></H3><PRE>
268 The <STRONG>putwin</STRONG> and <STRONG>getwin</STRONG> functions have several issues with portability:
270 <STRONG>o</STRONG> The files written and read by these functions use an implementa-
271 tion-specific format. Although the format is an obvious target for
272 standardization, it has been overlooked.
274 Interestingly enough, according to the copyright dates in Solaris
275 source, the functions (along with <STRONG>scr_init</STRONG>, etc.) originated with
276 the University of California, Berkeley (in 1982) and were later (in
277 1988) incorporated into SVr4. Oddly, there are no such functions
278 in the 4.3BSD curses sources.
280 <STRONG>o</STRONG> Most implementations simply dump the binary <STRONG>WINDOW</STRONG> structure to the
281 file. These include SVr4 curses, NetBSD and PDCurses, as well as
282 older <STRONG>ncurses</STRONG> versions. This implementation (as well as the X/Open
283 variant of Solaris curses, dated 1995) uses textual dumps.
285 The implementations which use binary dumps use block-I/O (the
286 <STRONG>fwrite</STRONG> and <STRONG>fread</STRONG> functions). Those that use textual dumps use
287 buffered-I/O. A few applications may happen to write extra data in
288 the file using these functions. Doing that can run into problems
289 mixing block- and buffered-I/O. This implementation reduces the
290 problem on writes by flushing the output. However, reading from a
291 file written using mixed schemes may not be successful.
294 </PRE><H3><a name="h3-unctrl_wunctrl">unctrl/wunctrl</a></H3><PRE>
295 The XSI Curses standard, Issue 4 describes these functions. It states
296 that <STRONG>unctrl</STRONG> and <STRONG>wunctrl</STRONG> will return a null pointer if unsuccessful, but
297 does not define any error conditions. This implementation checks for
300 <STRONG>o</STRONG> the parameter is a 7-bit US-ASCII code. This is the case that
301 X/Open Curses documented.
303 <STRONG>o</STRONG> the parameter is in the range 128-159, i.e., a C1 control code. If
304 <STRONG>use_legacy_coding</STRONG> has been called with a <STRONG>2</STRONG> parameter, <STRONG>unctrl</STRONG> re-
305 turns the parameter, i.e., a one-character string with the parame-
306 ter as the first character. Otherwise, it returns "~@", "~A",
307 etc., analogous to "^@", "^A", C0 controls.
309 X/Open Curses does not document whether <STRONG>unctrl</STRONG> can be called before
310 initializing curses. This implementation permits that, and returns
311 the "~@", etc., values in that case.
313 <STRONG>o</STRONG> parameter values outside the 0 to 255 range. <STRONG>unctrl</STRONG> returns a null
316 The strings returned by <STRONG>unctrl</STRONG> in this implementation are determined at
317 compile time, showing C1 controls from the upper-128 codes with a "~"
318 prefix rather than "^". Other implementations have different conven-
319 tions. For example, they may show both sets of control characters with
320 "^", and strip the parameter to 7 bits. Or they may ignore C1 controls
321 and treat all of the upper-128 codes as printable. This implementation
322 uses 8 bits but does not modify the string to reflect locale. The
323 <STRONG>use_legacy_coding</STRONG> function allows the caller to change the output of
324 <STRONG>unctrl</STRONG>.
326 Likewise, the <STRONG><A HREF="curs_inopts.3x.html">meta(3x)</A></STRONG> function allows the caller to change the output
327 of <STRONG>keyname</STRONG>, i.e., it determines whether to use the "M-" prefix for
328 "meta" keys (codes in the range 128 to 255). Both <STRONG>use_legacy_coding</STRONG>
329 and <STRONG>meta</STRONG> succeed only after curses is initialized. X/Open Curses does
330 not document the treatment of codes 128 to 159. When treating them as
331 "meta" keys (or if <STRONG>keyname</STRONG> is called before initializing curses), this
332 implementation returns strings "M-^@", "M-^A", etc.
335 </PRE><H3><a name="h3-use_env_use_tioctl">use_env/use_tioctl</a></H3><PRE>
336 If <STRONG>ncurses</STRONG> is configured to provide the sp-functions extension, the
337 state of <STRONG>use_env</STRONG> and <STRONG>use_tioctl</STRONG> may be updated before creating each
338 <EM>screen</EM> rather than once only (<STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG>). This feature of
339 <STRONG>use_env</STRONG> is not provided by other implementation of curses.
342 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
343 <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><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>,
344 <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>, <STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG>, <STRONG>curs_vari-</STRONG>
345 <STRONG><A HREF="curs_variables.3x.html">ables(3x)</A></STRONG>, <STRONG><A HREF="legacy_coding.3x.html">legacy_coding(3x)</A></STRONG>.
349 <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
353 <li><a href="#h2-NAME">NAME</a></li>
354 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
355 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
357 <li><a href="#h3-unctrl">unctrl</a></li>
358 <li><a href="#h3-keyname_key_name">keyname/key_name</a></li>
359 <li><a href="#h3-filter_nofilter">filter/nofilter</a></li>
360 <li><a href="#h3-use_env">use_env</a></li>
361 <li><a href="#h3-use_tioctl">use_tioctl</a></li>
362 <li><a href="#h3-putwin_getwin">putwin/getwin</a></li>
363 <li><a href="#h3-delay_output">delay_output</a></li>
364 <li><a href="#h3-flushinp">flushinp</a></li>
367 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
368 <li><a href="#h2-PORTABILITY">PORTABILITY</a>
370 <li><a href="#h3-filter">filter</a></li>
371 <li><a href="#h3-keyname">keyname</a></li>
372 <li><a href="#h3-nofilter_use_tioctl">nofilter/use_tioctl</a></li>
373 <li><a href="#h3-putwin_getwin">putwin/getwin</a></li>
374 <li><a href="#h3-unctrl_wunctrl">unctrl/wunctrl</a></li>
375 <li><a href="#h3-use_env_use_tioctl">use_env/use_tioctl</a></li>
378 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>