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30 * @Id: curs_util.3x,v 1.48 2017/04/22 14:05:14 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. The effect is that, during those calls, <STRONG>LINES</STRONG> is set to 1;
114 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;
115 and the <STRONG>home</STRONG> string is set to the value of <STRONG>cr</STRONG>.
117 The <STRONG>nofilter</STRONG> routine cancels the effect of a preceding <STRONG>filter</STRONG> call.
118 That allows the caller to initialize a screen on a different device,
119 using a different value of <STRONG>$TERM</STRONG>. The limitation arises because the
120 <STRONG>filter</STRONG> routine modifies the in-memory copy of the terminal information.
123 </PRE><H3><a name="h3-use_env">use_env</a></H3><PRE>
124 The <STRONG>use_env</STRONG> routine, if used, should be called before <STRONG>initscr</STRONG> or
125 <STRONG>newterm</STRONG> are called (because those compute the screen size). It modi-
126 fies the way <STRONG>ncurses</STRONG> treats environment variables when determining the
129 <STRONG>o</STRONG> Normally <STRONG>ncurses</STRONG> looks first at the terminal database for the
132 If <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> for parameter, it stops here un-
133 less If <STRONG>use_tioctl</STRONG> was also called with <STRONG>TRUE</STRONG> for parameter.
135 <STRONG>o</STRONG> Then it asks for the screen size via operating system calls. If
136 successful, it overrides the values from the terminal database.
138 <STRONG>o</STRONG> Finally (unless <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> parameter), <STRONG>ncurses</STRONG>
139 examines the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG> environment variables, using a value
140 in those to override the results from the operating system or ter-
143 <STRONG>Ncurses</STRONG> also updates the screen size in response to SIGWINCH, un-
144 less overridden by the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG> environment variables,
147 </PRE><H3><a name="h3-use_tioctl">use_tioctl</a></H3><PRE>
148 The <STRONG>use_tioctl</STRONG> routine, if used, should be called before <STRONG>initscr</STRONG> or
149 <STRONG>newterm</STRONG> are called (because those compute the screen size). After
150 <STRONG>use_tioctl</STRONG> is called with <STRONG>TRUE</STRONG> as an argument, <STRONG>ncurses</STRONG> modifies the
151 last step in its computation of screen size as follows:
153 <STRONG>o</STRONG> checks if the <STRONG>LINES</STRONG> and <STRONG>COLUMNS</STRONG> environment variables are set to a
154 number greater than zero.
156 <STRONG>o</STRONG> for each, <STRONG>ncurses</STRONG> updates the corresponding environment variable
157 with the value that it has obtained via operating system call or
158 from the terminal database.
160 <STRONG>o</STRONG> <STRONG>ncurses</STRONG> re-fetches the value of the environment variables so that
161 it is still the environment variables which set the screen size.
163 The <STRONG>use_env</STRONG> and <STRONG>use_tioctl</STRONG> routines combine as summarized here:
165 <EM>use</EM><STRONG>_</STRONG><EM>env</EM> <EM>use</EM><STRONG>_</STRONG><EM>tioctl</EM> <EM>Summary</EM>
166 ----------------------------------------------------------------
167 TRUE FALSE This is the default behavior. <STRONG>ncurses</STRONG>
168 uses operating system calls unless over-
169 ridden by $LINES or $COLUMNS environment
171 TRUE TRUE <STRONG>ncurses</STRONG> updates $LINES and $COLUMNS
172 based on operating system calls.
173 FALSE TRUE <STRONG>ncurses</STRONG> ignores $LINES and $COLUMNS, us-
174 es operating system calls to obtain
176 FALSE FALSE <STRONG>ncurses</STRONG> relies on the terminal database
180 </PRE><H3><a name="h3-putwin_getwin">putwin/getwin</a></H3><PRE>
181 The <STRONG>putwin</STRONG> routine writes all data associated with window (or pad) <EM>win</EM>
182 into the file to which <EM>filep</EM> points. This information can be later re-
183 trieved using the <STRONG>getwin</STRONG> function.
185 The <STRONG>getwin</STRONG> routine reads window related data stored in the file by
186 <STRONG>putwin</STRONG>. The routine then creates and initializes a new window using
187 that data. It returns a pointer to the new window. There are a few
190 <STRONG>o</STRONG> the data written is a copy of the <STRONG>WINDOW</STRONG> structure, and its associ-
191 ated character cells. The format differs between the wide-charac-
192 ter (ncursesw) and non-wide (ncurses) libraries. You can transfer
193 data between the two, however.
195 <STRONG>o</STRONG> the retrieved window is always created as a top-level window (or
196 pad), rather than a subwindow.
198 <STRONG>o</STRONG> the window's character cells contain the color pair <EM>value</EM>, but not
199 the actual color <EM>numbers</EM>. If cells in the retrieved window use
200 color pairs which have not been created in the application using
201 <STRONG>init_pair</STRONG>, they will not be colored when the window is refreshed.
204 </PRE><H3><a name="h3-delay_output">delay_output</a></H3><PRE>
205 The <STRONG>delay_output</STRONG> routine inserts an <EM>ms</EM> millisecond pause in output.
206 This routine should not be used extensively because padding characters
207 are used rather than a CPU pause. If no padding character is speci-
208 fied, this uses <STRONG>napms</STRONG> to perform the delay.
211 </PRE><H3><a name="h3-flushinp">flushinp</a></H3><PRE>
212 The <STRONG>flushinp</STRONG> routine throws away any typeahead that has been typed by
213 the user and has not yet been read by the program.
216 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
217 Except for <STRONG>flushinp</STRONG>, routines that return an integer return <STRONG>ERR</STRONG> upon
218 failure and <STRONG>OK</STRONG> (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>")
219 upon successful completion.
221 Routines that return pointers return <STRONG>NULL</STRONG> on error.
223 X/Open does not define any error conditions. In this implementation
225 <STRONG>flushinp</STRONG>
226 returns an error if the terminal was not initialized.
228 <STRONG>putwin</STRONG>
229 returns an error if the associated <STRONG>fwrite</STRONG> calls return an er-
233 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
235 </PRE><H3><a name="h3-filter">filter</a></H3><PRE>
236 The SVr4 documentation describes the action of <STRONG>filter</STRONG> only in the
237 vaguest terms. The description here is adapted from the XSI Curses
238 standard (which erroneously fails to describe the disabling of <STRONG>cuu</STRONG>).
241 </PRE><H3><a name="h3-keyname">keyname</a></H3><PRE>
242 The <STRONG>keyname</STRONG> function may return the names of user-defined string capa-
243 bilities which are defined in the terminfo entry via the <STRONG>-x</STRONG> option of
244 <STRONG>tic</STRONG>. This implementation automatically assigns at run-time keycodes to
245 user-defined strings which begin with "k". The keycodes start at
246 KEY_MAX, but are not guaranteed to be the same value for different runs
247 because user-defined codes are merged from all terminal descriptions
248 which have been loaded. The <STRONG><A HREF="curs_extend.3x.html">use_extended_names(3x)</A></STRONG> function controls
249 whether this data is loaded when the terminal description is read by
253 </PRE><H3><a name="h3-nofilter_use_tioctl">nofilter/use_tioctl</a></H3><PRE>
254 The <STRONG>nofilter</STRONG> and <STRONG>use_tioctl</STRONG> routines are specific to <STRONG>ncurses</STRONG>. They
255 were not supported on Version 7, BSD or System V implementations. It
256 is recommended that any code depending on <STRONG>ncurses</STRONG> extensions be condi-
257 tioned using NCURSES_VERSION.
260 </PRE><H3><a name="h3-putwin_getwin">putwin/getwin</a></H3><PRE>
261 The <STRONG>putwin</STRONG> and <STRONG>getwin</STRONG> functions have several issues with portability:
263 <STRONG>o</STRONG> The files written and read by these functions use an implementa-
264 tion-specific format. Although the format is an obvious target for
265 standardization, it has been overlooked.
267 Interestingly enough, according to the copyright dates in Solaris
268 source, the functions (along with <STRONG>scr_init</STRONG>, etc.) originated with
269 the University of California, Berkeley (in 1982) and were later (in
270 1988) incorporated into SVr4. Oddly, there are no such functions
271 in the 4.3BSD curses sources.
273 <STRONG>o</STRONG> Most implementations simply dump the binary <STRONG>WINDOW</STRONG> structure to the
274 file. These include SVr4 curses, NetBSD and PDCurses, as well as
275 older <STRONG>ncurses</STRONG> versions. This implementation (as well as the X/Open
276 variant of Solaris curses, dated 1995) uses textual dumps.
278 The implementations which use binary dumps use block-I/O (the
279 <STRONG>fwrite</STRONG> and <STRONG>fread</STRONG> functions). Those that use textual dumps use
280 buffered-I/O. A few applications may happen to write extra data in
281 the file using these functions. Doing that can run into problems
282 mixing block- and buffered-I/O. This implementation reduces the
283 problem on writes by flushing the output. However, reading from a
284 file written using mixed schemes may not be successful.
287 </PRE><H3><a name="h3-unctrl_wunctrl">unctrl/wunctrl</a></H3><PRE>
288 The XSI Curses standard, Issue 4 describes these functions. It states
289 that <STRONG>unctrl</STRONG> and <STRONG>wunctrl</STRONG> will return a null pointer if unsuccessful, but
290 does not define any error conditions. This implementation checks for
293 <STRONG>o</STRONG> the parameter is a 7-bit US-ASCII code. This is the case that
294 X/Open Curses documented.
296 <STRONG>o</STRONG> the parameter is in the range 128-159, i.e., a C1 control code. If
297 <STRONG>use_legacy_coding</STRONG> has been called with a <STRONG>2</STRONG> parameter, <STRONG>unctrl</STRONG> re-
298 turns the parameter, i.e., a one-character string with the parame-
299 ter as the first character. Otherwise, it returns "~@", "~A",
300 etc., analogous to "^@", "^A", C0 controls.
302 X/Open Curses does not document whether <STRONG>unctrl</STRONG> can be called before
303 initializing curses. This implementation permits that, and returns
304 the "~@", etc., values in that case.
306 <STRONG>o</STRONG> parameter values outside the 0 to 255 range. <STRONG>unctrl</STRONG> returns a null
309 The strings returned by <STRONG>unctrl</STRONG> in this implementation are determined at
310 compile time, showing C1 controls from the upper-128 codes with a "~"
311 prefix rather than "^". Other implementations have different conven-
312 tions. For example, they may show both sets of control characters with
313 "^", and strip the parameter to 7 bits. Or they may ignore C1 controls
314 and treat all of the upper-128 codes as printable. This implementation
315 uses 8 bits but does not modify the string to reflect locale. The
316 <STRONG>use_legacy_coding</STRONG> function allows the caller to change the output of
317 <STRONG>unctrl</STRONG>.
319 Likewise, the <STRONG><A HREF="curs_inopts.3x.html">meta(3x)</A></STRONG> function allows the caller to change the output
320 of <STRONG>keyname</STRONG>, i.e., it determines whether to use the "M-" prefix for
321 "meta" keys (codes in the range 128 to 255). Both <STRONG>use_legacy_coding</STRONG>
322 and <STRONG>meta</STRONG> succeed only after curses is initialized. X/Open Curses does
323 not document the treatment of codes 128 to 159. When treating them as
324 "meta" keys (or if <STRONG>keyname</STRONG> is called before initializing curses), this
325 implementation returns strings "M-^@", "M-^A", etc.
328 </PRE><H3><a name="h3-use_env_use_tioctl">use_env/use_tioctl</a></H3><PRE>
329 If <STRONG>ncurses</STRONG> is configured to provide the sp-functions extension, the
330 state of <STRONG>use_env</STRONG> and <STRONG>use_tioctl</STRONG> may be updated before creating each
331 <EM>screen</EM> rather than once only (<STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG>). This feature of
332 <STRONG>use_env</STRONG> is not provided by other implementation of curses.
335 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
336 <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>,
337 <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>
338 <STRONG><A HREF="curs_variables.3x.html">ables(3x)</A></STRONG>, <STRONG><A HREF="legacy_coding.3x.html">legacy_coding(3x)</A></STRONG>.
342 <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
346 <li><a href="#h2-NAME">NAME</a></li>
347 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
348 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
350 <li><a href="#h3-unctrl">unctrl</a></li>
351 <li><a href="#h3-keyname_key_name">keyname/key_name</a></li>
352 <li><a href="#h3-filter_nofilter">filter/nofilter</a></li>
353 <li><a href="#h3-use_env">use_env</a></li>
354 <li><a href="#h3-use_tioctl">use_tioctl</a></li>
355 <li><a href="#h3-putwin_getwin">putwin/getwin</a></li>
356 <li><a href="#h3-delay_output">delay_output</a></li>
357 <li><a href="#h3-flushinp">flushinp</a></li>
360 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
361 <li><a href="#h2-PORTABILITY">PORTABILITY</a>
363 <li><a href="#h3-filter">filter</a></li>
364 <li><a href="#h3-keyname">keyname</a></li>
365 <li><a href="#h3-nofilter_use_tioctl">nofilter/use_tioctl</a></li>
366 <li><a href="#h3-putwin_getwin">putwin/getwin</a></li>
367 <li><a href="#h3-unctrl_wunctrl">unctrl/wunctrl</a></li>
368 <li><a href="#h3-use_env_use_tioctl">use_env/use_tioctl</a></li>
371 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>