1<!-- 2 **************************************************************************** 3 * Copyright 2018-2023,2024 Thomas E. Dickey * 4 * Copyright 1998-2010,2017 Free Software Foundation, Inc. * 5 * * 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: * 13 * * 14 * The above copyright notice and this permission notice shall be included * 15 * in all copies or substantial portions of the Software. * 16 * * 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. * 24 * * 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 * 28 * authorization. * 29 **************************************************************************** 30 * @Id: curs_getstr.3x,v 1.58 2024/04/20 19:18:18 tom Exp @ 31--> 32<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> 33<HTML> 34<HEAD> 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 2024-04-20 ncurses 6.5 Library calls</TITLE> 38<link rel="author" href="mailto:bug-ncurses@gnu.org"> 39 40</HEAD> 41<BODY> 42<H1 class="no-header">curs_getstr 3x 2024-04-20 ncurses 6.5 Library calls</H1> 43<PRE> 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> 45 46 47 48 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 <EM>curses</EM> terminal keyboard 52 53 54</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> 55 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG> 56 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> 61 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> 66 67 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: 71 72 <STRONG>o</STRONG> The terminating character is not included in the returned string. 73 74 <STRONG>o</STRONG> In all instances, the end of the string is terminated by a NUL. 75 76 <STRONG>o</STRONG> The function stores the result in the area pointed to by the <EM>str</EM> 77 parameter. 78 79 <STRONG>o</STRONG> The function reads at most <EM>n</EM> characters, thus preventing a possible 80 overflow of the input buffer. 81 82 Any attempt to enter more characters (other than the terminating 83 newline or carriage return) causes a beep. 84 85 Function keys also cause a beep and are ignored. 86 87 The user's <EM>erase</EM> and <EM>kill</EM> characters are interpreted: 88 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. 91 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. 94 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. 97 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 100 (typically a left motion). 101 102 The <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, and <STRONG>wgetnstr</STRONG> functions are 103 identical to the <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, and <STRONG>wgetstr</STRONG> functions, 104 respectively, except that the <STRONG>*n*</STRONG> versions read at most <EM>n</EM> characters, 105 letting the application prevent overflow of the input buffer. 106 107 108</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE> 109 All of these functions return the integer <STRONG>OK</STRONG> upon successful 110 completion. (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>") If 111 unsuccessful, they return <STRONG>ERR</STRONG>. 112 113 X/Open defines no error conditions. 114 115 In this implementation, these functions return an error 116 117 <STRONG>o</STRONG> if the window pointer is null, 118 119 <STRONG>o</STRONG> if its timeout expires without having any data, or 120 121 <STRONG>o</STRONG> if the associated call to <STRONG>wgetch</STRONG> failed. 122 123 This implementation provides an extension as well. If a <STRONG>SIGWINCH</STRONG> 124 interrupts the function, it will return <STRONG>KEY_RESIZE</STRONG> rather than <STRONG>OK</STRONG> or 125 <STRONG>ERR</STRONG>. 126 127 Functions prefixed with "mv" first perform cursor movement and fail if 128 the position (<EM>y</EM>, <EM>x</EM>) is outside the window boundaries. 129 130 131</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE> 132 Any of these functions other than <STRONG>wgetnstr</STRONG> may be macros. 133 134 Using <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, or <STRONG>wgetstr</STRONG> to read a line that 135 overflows the array pointed to by <STRONG>str</STRONG> causes undefined results. The 136 use of <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, or <STRONG>wgetnstr</STRONG>, respectively, is 137 recommended. 138 139 140</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. 143 144 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>. 146 147 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", 150 without giving details. It lied. In fact, the "character" value 151 appended to the string by those implementations was predictable but not 152 useful (being, in fact, the low-order eight bits of the key's KEY_ 153 value). 154 155 The functions <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, and <STRONG>mvwgetnstr</STRONG> were present but not 156 documented in SVr4. 157 158 X/Open Curses, Issue 5 (2007) stated that these functions "read at most 159 <EM>n</EM> bytes" but did not state whether the terminating NUL is counted in 160 that limit. X/Open Curses, Issue 7 (2009) changed that to say they 161 "read at most <EM>n</EM>-1 bytes" to allow for the terminating NUL. As of 2018, 162 some implementations count it, some do not: 163 164 <STRONG>o</STRONG> <EM>ncurses</EM> 6.1 and PDCurses do not count the NUL in the given limit, 165 while 166 167 <STRONG>o</STRONG> Solaris SVr4 and NetBSD curses count the NUL as part of the limit. 168 169 <STRONG>o</STRONG> Solaris xcurses provides both: its wide-character <STRONG>wget_nstr</STRONG> 170 reserves a NUL, but its <STRONG>wgetnstr</STRONG> does not count the NUL 171 consistently. 172 173 In SVr4 curses, a negative value of <EM>n</EM> tells <STRONG>wgetnstr</STRONG> to assume that the 174 caller's buffer is large enough to hold the result, i.e., to act like 175 <STRONG>wgetstr</STRONG>. X/Open Curses does not mention this (or anything related to 176 negative or zero values of <EM>n</EM>), however most implementations use the 177 feature, with different limits: 178 179 <STRONG>o</STRONG> Solaris SVr4 curses and PDCurses limit the result to 255 bytes. 180 Other Unix systems than Solaris are likely to use the same limit. 181 182 <STRONG>o</STRONG> Solaris xcurses limits the result to <STRONG>LINE_MAX</STRONG> bytes. 183 184 <STRONG>o</STRONG> NetBSD 7 assumes no particular limit for the result from <STRONG>wgetstr</STRONG>. 185 However, it limits the <STRONG>wgetnstr</STRONG> parameter <EM>n</EM> to ensure that it is 186 greater than zero. 187 188 A comment in NetBSD's source code states that this is specified in 189 SUSv2. 190 191 <STRONG>o</STRONG> <EM>ncurses</EM> (before 6.2) assumes no particular limit for the result 192 from <STRONG>wgetstr</STRONG>, and treats the <EM>n</EM> parameter of <STRONG>wgetnstr</STRONG> like SVr4 193 curses. 194 195 <STRONG>o</STRONG> <EM>ncurses</EM> 6.2 uses <STRONG>LINE_MAX</STRONG>, or a larger (system-dependent) value 196 which the <STRONG>sysconf</STRONG> function may provide. If neither <STRONG>LINE_MAX</STRONG> or 197 <STRONG>sysconf</STRONG> is available, <EM>ncurses</EM> uses the POSIX value for <STRONG>LINE_MAX</STRONG> (a 198 2048 byte limit). In either case, it reserves a byte for the 199 terminating NUL. 200 201 Although <STRONG>getnstr</STRONG> is equivalent to a series of calls to <STRONG>getch</STRONG>, it also 202 makes changes to the curses modes to allow simple editing of the input 203 buffer: 204 205 <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> 206 modes, and sets <STRONG>nl</STRONG>, <STRONG>noecho</STRONG>, <STRONG>noraw</STRONG>, and <STRONG>cbreak</STRONG>. 207 208 <STRONG>getnstr</STRONG> handles the echoing of characters, rather than relying on 209 the caller to set an appropriate mode. 210 211 <STRONG>o</STRONG> It also obtains the <EM>erase</EM> and <EM>kill</EM> characters from <STRONG>erasechar</STRONG> and 212 <STRONG>killchar</STRONG>, respectively. 213 214 <STRONG>o</STRONG> On return, <STRONG>getnstr</STRONG> restores the modes to their previous values. 215 216 Other implementations differ in their treatment of special characters: 217 218 <STRONG>o</STRONG> While they may set the <EM>echo</EM> mode, other implementations do not 219 modify the <EM>raw</EM> mode, They may take the <EM>cbreak</EM> mode set by the 220 caller into account when deciding whether to handle echoing within 221 <STRONG>getnstr</STRONG> or as a side-effect of the <STRONG>getch</STRONG> calls. 222 223 <STRONG>o</STRONG> The original <EM>ncurses</EM> (as <EM>pcurses</EM> in 1986) set <STRONG>noraw</STRONG> and <STRONG>cbreak</STRONG> when 224 accepting input for <STRONG>getnstr</STRONG>. That may have been done to make 225 function- and cursor-keys work; it is not necessary with <EM>ncurses</EM>. 226 227 Since 1995, <EM>ncurses</EM> has provided signal handlers for INTR and QUIT 228 (e.g., <STRONG>^C</STRONG> or <STRONG>^\</STRONG>). With the <STRONG>noraw</STRONG> and <STRONG>cbreak</STRONG> settings, those may 229 catch a signal and stop the program, where other implementations 230 allow one to enter those characters in the buffer. 231 232 <STRONG>o</STRONG> Starting in 2021 (<EM>ncurses</EM> 6.3), <STRONG>getnstr</STRONG> sets <STRONG>raw</STRONG>, rather than <STRONG>noraw</STRONG> 233 and <STRONG>cbreak</STRONG> for better compatibility with SVr4-curses, e.g., 234 allowing one to enter a <STRONG>^C</STRONG> into the buffer. 235 236 237</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE> 238 <STRONG><A HREF="curs_get_wstr.3x.html">curs_get_wstr(3x)</A></STRONG> describes comparable functions of the <EM>ncurses</EM> library 239 in its wide-character configuration (<EM>ncursesw</EM>). 240 241 <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> 242 243 244 245ncurses 6.5 2024-04-20 <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG> 246</PRE> 247<div class="nav"> 248<ul> 249<li><a href="#h2-NAME">NAME</a></li> 250<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li> 251<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li> 252<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li> 253<li><a href="#h2-NOTES">NOTES</a></li> 254<li><a href="#h2-PORTABILITY">PORTABILITY</a></li> 255<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li> 256</ul> 257</div> 258</BODY> 259</HTML> 260