2 ****************************************************************************
3 * Copyright 2018-2022,2023 Thomas E. Dickey *
4 * Copyright 1998-2010,2017 Free Software Foundation, Inc. *
6 * Permission is hereby granted, free of charge, to any person obtaining a *
7 * copy of this software and associated documentation files (the *
8 * "Software"), to deal in the Software without restriction, including *
9 * without limitation the rights to use, copy, modify, merge, publish, *
10 * distribute, distribute with modifications, sublicense, and/or sell *
11 * copies of the Software, and to permit persons to whom the Software is *
12 * furnished to do so, subject to the following conditions: *
14 * The above copyright notice and this permission notice shall be included *
15 * in all copies or substantial portions of the Software. *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
20 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
21 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
22 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
23 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
25 * Except as contained in this notice, the name(s) of the above copyright *
26 * holders shall not be used in advertising or otherwise to promote the *
27 * sale, use or other dealings in this Software without prior written *
29 ****************************************************************************
30 * @Id: curs_getstr.3x,v 1.42 2023/08/05 12:14:30 tom Exp @
32 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
35 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
36 <meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts">
37 <TITLE>curs_getstr 3x 2023-08-05 ncurses 6.4 Library calls</TITLE>
38 <link rel="author" href="mailto:bug-ncurses@gnu.org">
42 <H1 class="no-header">curs_getstr 3x 2023-08-05 ncurses 6.4 Library calls</H1>
44 <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50 <STRONG>getstr</STRONG>, <STRONG>getnstr</STRONG>, <STRONG>wgetstr</STRONG>, <STRONG>wgetnstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetstr</STRONG>,
51 <STRONG>mvwgetnstr</STRONG> - accept character strings from <STRONG>curses</STRONG> terminal keyboard
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
57 <STRONG>int</STRONG> <STRONG>getstr(char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>);</STRONG>
58 <STRONG>int</STRONG> <STRONG>getnstr(char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>n</EM><STRONG>);</STRONG>
59 <STRONG>int</STRONG> <STRONG>wgetstr(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>);</STRONG>
60 <STRONG>int</STRONG> <STRONG>wgetnstr(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>n</EM><STRONG>);</STRONG>
62 <STRONG>int</STRONG> <STRONG>mvgetstr(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>);</STRONG>
63 <STRONG>int</STRONG> <STRONG>mvwgetstr(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>);</STRONG>
64 <STRONG>int</STRONG> <STRONG>mvgetnstr(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>n</EM><STRONG>);</STRONG>
65 <STRONG>int</STRONG> <STRONG>mvwgetnstr(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>str</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>n</EM><STRONG>);</STRONG>
68 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
69 The function <STRONG>wgetnstr</STRONG> is equivalent to a series of calls to <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>,
70 until a newline or carriage return terminates the series:
72 <STRONG>o</STRONG> The terminating character is not included in the returned string.
74 <STRONG>o</STRONG> In all instances, the end of the string is terminated by a NUL.
76 <STRONG>o</STRONG> The function stores the result in the area pointed to by the <EM>str</EM>
79 <STRONG>o</STRONG> The function reads at most <EM>n</EM> characters, thus preventing a possible
80 overflow of the input buffer.
82 Any attempt to enter more characters (other than the terminating
83 newline or carriage return) causes a beep.
85 Function keys also cause a beep and are ignored.
87 The user's <EM>erase</EM> and <EM>kill</EM> characters are interpreted:
89 <STRONG>o</STRONG> The <EM>erase</EM> character (e.g., <STRONG>^H</STRONG>) erases the character at the end of
90 the buffer, moving the cursor to the left.
92 If <EM>keypad</EM> mode is on for the window, <STRONG>KEY_LEFT</STRONG> and <STRONG>KEY_BACKSPACE</STRONG> are
93 both considered equivalent to the user's <EM>erase</EM> character.
95 <STRONG>o</STRONG> The <EM>kill</EM> character (e.g., <STRONG>^U</STRONG>) erases the entire buffer, leaving the
96 cursor at the beginning of the buffer.
98 Characters input are echoed only if <STRONG>echo</STRONG> is currently on. In that
99 case, backspace is echoed as deletion of the previous character (typi-
100 cally a left motion).
102 The <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, and <STRONG>wgetnstr</STRONG> functions are identi-
103 cal to the <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, and <STRONG>wgetstr</STRONG> functions, respec-
104 tively, except that the <STRONG>*n*</STRONG> versions read at most <EM>n</EM> characters, letting
105 the application prevent overflow of the input buffer.
108 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
109 Any of these functions other than <STRONG>wgetnstr</STRONG> may be macros.
111 Using <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, or <STRONG>wgetstr</STRONG> to read a line that over-
112 flows the array pointed to by <STRONG>str</STRONG> causes undefined results. The use of
113 <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, or <STRONG>wgetnstr</STRONG>, respectively, is recom-
117 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
118 All of these functions return the integer <STRONG>OK</STRONG> upon successful comple-
119 tion. (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>") If un-
120 successful, they return <STRONG>ERR</STRONG>.
122 X/Open defines no error conditions.
124 In this implementation, these functions return an error
126 <STRONG>o</STRONG> if the window pointer is null,
128 <STRONG>o</STRONG> if its timeout expires without having any data, or
130 <STRONG>o</STRONG> if the associated call to <STRONG>wgetch</STRONG> failed.
132 This implementation provides an extension as well. If a <STRONG>SIGWINCH</STRONG> in-
133 terrupts the function, it will return <STRONG>KEY_RESIZE</STRONG> rather than <STRONG>OK</STRONG> or <STRONG>ERR</STRONG>.
135 Functions with a "mv" prefix first perform a cursor movement using
136 <STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if
137 the window pointer is null.
140 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
141 These functions are described in The Single Unix Specification, Version
142 2. No error conditions are defined.
144 This implementation returns <STRONG>ERR</STRONG> if the window pointer is null, or if
145 the lower-level <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> call returns an <STRONG>ERR</STRONG>.
147 SVr3 and early SVr4 curses implementations did not reject function
148 keys; the SVr4.0 documentation claimed that "special keys" (such as
149 function keys, "home" key, "clear" key, <EM>etc</EM>.) are "interpreted", with-
150 out giving details. It lied. In fact, the "character" value appended
151 to the string by those implementations was predictable but not useful
152 (being, in fact, the low-order eight bits of the key's KEY_ value).
154 The functions <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, and <STRONG>mvwgetnstr</STRONG> were present but not
157 X/Open Curses, Issue 5 (2007) stated that these functions "read at most
158 <EM>n</EM> bytes" but did not state whether the terminating NUL is counted in
159 that limit. X/Open Curses, Issue 7 (2009) changed that to say they
160 "read at most <EM>n</EM>-1 bytes" to allow for the terminating NUL. As of 2018,
161 some implementations count it, some do not:
163 <STRONG>o</STRONG> ncurses 6.1 and PDCurses do not count the NUL in the given limit,
166 <STRONG>o</STRONG> Solaris SVr4 and NetBSD curses count the NUL as part of the limit.
168 <STRONG>o</STRONG> Solaris xcurses provides both: its wide-character <STRONG>wget_nstr</STRONG> re-
169 serves a NUL, but its <STRONG>wgetnstr</STRONG> does not count the NUL consistently.
171 In SVr4 curses, a negative value of <EM>n</EM> tells <STRONG>wgetnstr</STRONG> to assume that the
172 caller's buffer is large enough to hold the result, i.e., to act like
173 <STRONG>wgetstr</STRONG>. X/Open Curses does not mention this (or anything related to
174 negative or zero values of <EM>n</EM>), however most implementations use the
175 feature, with different limits:
177 <STRONG>o</STRONG> Solaris SVr4 curses and PDCurses limit the result to 255 bytes.
178 Other Unix systems than Solaris are likely to use the same limit.
180 <STRONG>o</STRONG> Solaris xcurses limits the result to <STRONG>LINE_MAX</STRONG> bytes.
182 <STRONG>o</STRONG> NetBSD 7 assumes no particular limit for the result from <STRONG>wgetstr</STRONG>.
183 However, it limits the <STRONG>wgetnstr</STRONG> parameter <EM>n</EM> to ensure that it is
186 A comment in NetBSD's source code states that this is specified in
189 <STRONG>o</STRONG> ncurses (before 6.2) assumes no particular limit for the result
190 from <STRONG>wgetstr</STRONG>, and treats the <EM>n</EM> parameter of <STRONG>wgetnstr</STRONG> like SVr4
193 <STRONG>o</STRONG> ncurses 6.2 uses <STRONG>LINE_MAX</STRONG>, or a larger (system-dependent) value
194 which the <STRONG>sysconf</STRONG> function may provide. If neither <STRONG>LINE_MAX</STRONG> or
195 <STRONG>sysconf</STRONG> is available, ncurses uses the POSIX value for <STRONG>LINE_MAX</STRONG> (a
196 2048 byte limit). In either case, it reserves a byte for the ter-
199 Although <STRONG>getnstr</STRONG> is equivalent to a series of calls to <STRONG>getch</STRONG>, it also
200 makes changes to the curses modes to allow simple editing of the input
203 <STRONG>o</STRONG> <STRONG>getnstr</STRONG> saves the current value of the <STRONG>nl</STRONG>, <STRONG>echo</STRONG>, <STRONG>raw</STRONG> and <STRONG>cbreak</STRONG>
204 modes, and sets <STRONG>nl</STRONG>, <STRONG>noecho</STRONG>, <STRONG>noraw</STRONG>, and <STRONG>cbreak</STRONG>.
206 <STRONG>getnstr</STRONG> handles the echoing of characters, rather than relying on
207 the caller to set an appropriate mode.
209 <STRONG>o</STRONG> It also obtains the <EM>erase</EM> and <EM>kill</EM> characters from <STRONG>erasechar</STRONG> and
210 <STRONG>killchar</STRONG>, respectively.
212 <STRONG>o</STRONG> On return, <STRONG>getnstr</STRONG> restores the modes to their previous values.
214 Other implementations differ in their treatment of special characters:
216 <STRONG>o</STRONG> While they may set the <EM>echo</EM> mode, other implementations do not mod-
217 ify the <EM>raw</EM> mode, They may take the <EM>cbreak</EM> mode set by the caller
218 into account when deciding whether to handle echoing within <STRONG>getnstr</STRONG>
219 or as a side-effect of the <STRONG>getch</STRONG> calls.
221 <STRONG>o</STRONG> The original ncurses (as <EM>pcurses</EM> in 1986) set <STRONG>noraw</STRONG> and <STRONG>cbreak</STRONG> when
222 accepting input for <STRONG>getnstr</STRONG>. That may have been done to make func-
223 tion- and cursor-keys work; it is not necessary with ncurses.
225 Since 1995, ncurses has provided signal handlers for INTR and QUIT
226 (e.g., <STRONG>^C</STRONG> or <STRONG>^\</STRONG>). With the <STRONG>noraw</STRONG> and <STRONG>cbreak</STRONG> settings, those may
227 catch a signal and stop the program, where other implementations
228 allow one to enter those characters in the buffer.
230 <STRONG>o</STRONG> Starting in 2021 (ncurses 6.3), <STRONG>getnstr</STRONG> sets <STRONG>raw</STRONG>, rather than <STRONG>noraw</STRONG>
231 and <STRONG>cbreak</STRONG> for better compatibility with SVr4-curses, e.g., allow-
232 ing one to enter a <STRONG>^C</STRONG> into the buffer.
235 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
236 <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>, <STRONG><A HREF="curs_termattrs.3x.html">curs_termattrs(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>.
240 ncurses 6.4 2023-08-05 <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
244 <li><a href="#h2-NAME">NAME</a></li>
245 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
246 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
247 <li><a href="#h2-NOTES">NOTES</a></li>
248 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
249 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
250 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>