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_scanw.3x,v 1.41 2023/10/07 21:19:07 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_scanw 3x 2023-10-07 ncurses 6.4 Library calls</TITLE>
38 <link rel="author" href="mailto:bug-ncurses@gnu.org">
42 <H1 class="no-header">curs_scanw 3x 2023-10-07 ncurses 6.4 Library calls</H1>
44 <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG>
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50 <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG>, <STRONG>mvscanw</STRONG>, <STRONG>mvwscanw</STRONG>, <STRONG>vwscanw</STRONG>, <STRONG>vw_scanw</STRONG> - read formatted
51 input from a <EM>curses</EM> window
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
57 <STRONG>int</STRONG> <STRONG>scanw(const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>fmt</EM><STRONG>,</STRONG> <STRONG>...);</STRONG>
58 <STRONG>int</STRONG> <STRONG>wscanw(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>fmt</EM><STRONG>,</STRONG> <STRONG>...);</STRONG>
59 <STRONG>int</STRONG> <STRONG>mvscanw(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>fmt</EM><STRONG>,</STRONG> <STRONG>...);</STRONG>
60 <STRONG>int</STRONG> <STRONG>mvwscanw(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>const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>fmt</EM><STRONG>,</STRONG> <STRONG>...);</STRONG>
62 <STRONG>int</STRONG> <STRONG>vw_scanw(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>fmt</EM><STRONG>,</STRONG> <STRONG>va_list</STRONG> <EM>varglist</EM><STRONG>);</STRONG>
64 <EM>/*</EM> <EM>obsolete</EM> <EM>*/</EM>
65 <STRONG>int</STRONG> <STRONG>vwscanw(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>fmt</EM><STRONG>,</STRONG> <STRONG>va_list</STRONG> <EM>varglist</EM><STRONG>);</STRONG>
68 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
69 The <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG> and <STRONG>mvscanw</STRONG> routines are analogous to <STRONG>scanf</STRONG> [see
70 <STRONG>scanf(3)</STRONG>]. The effect of these routines is as though <STRONG>wgetstr</STRONG> were
71 called on the window, and the resulting line used as input for
72 <STRONG>sscanf(3)</STRONG>. Fields which do not map to a variable in the <EM>fmt</EM> field are
75 The <STRONG>vwscanw</STRONG> and <STRONG>vw_scanw</STRONG> routines are analogous to <STRONG>vscanf(3)</STRONG>. They
76 perform a <STRONG>wscanw</STRONG> using a variable argument list. The third argument is
77 a <STRONG>va_list</STRONG>, a pointer to a list of arguments, as defined in <STRONG><stdarg.h></STRONG>.
80 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
81 <STRONG>vwscanw</STRONG> returns <STRONG>ERR</STRONG> on failure and an integer equal to the number of
82 fields scanned on success.
84 Applications may use the return value from the <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG>, <STRONG>mvscanw</STRONG>
85 and <STRONG>mvwscanw</STRONG> routines to determine the number of fields which were
88 Functions with a "mv" prefix first perform a cursor movement using
89 <STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if
90 the window pointer is null.
93 </PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
94 While <STRONG>scanw</STRONG> was implemented in 4BSD, none of the BSD releases used it
95 until 4.4BSD (in a game). That early version of curses was before the
96 ANSI C standard. It did not use <varargs.h>, though that was
97 available. In 1991 (a couple of years after SVr4 was generally
98 available, and after the C standard was published), other developers
99 updated the library, using <stdarg.h> internally in 4.4BSD curses.
100 Even with this improvement, BSD curses did not use function prototypes
101 (or even declare functions) in the <curses.h> header until 1992.
103 SVr2 documented <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG> tersely as "scanf through <EM>stdscr</EM>" and
104 tersely as "scanf through <EM>win</EM>", respectively.
106 SVr3 added <STRONG>mvscanw</STRONG>, and <STRONG>mvwscanw</STRONG>, with a three-line summary saying that
107 they were analogous to <STRONG>scanf(3)</STRONG>, explaining that the string which would
108 be output from <STRONG>scanf(3)</STRONG> would instead be output using <STRONG>waddstr</STRONG> on the
109 given window. SVr3 also added <STRONG>vwscanw</STRONG>, saying that the third parameter
110 is a <STRONG>va_list</STRONG>, defined in <varargs.h>, and referring the reader to the
111 manual pages for <EM>varargs</EM> and <STRONG>vprintf</STRONG> for detailed descriptions.
112 (Because the SVr3 documentation does not mention <STRONG>vscanf</STRONG>, that reference
113 to <STRONG>vprintf</STRONG> may not be an error).
115 SVr4 added no new variations of <STRONG>scanw</STRONG>, but provided for using
116 <varargs.h> or <stdarg.h> to define the <STRONG>va_list</STRONG> type.
118 X/Open Curses added <STRONG>vw_scanw</STRONG> to replace <STRONG>vwscanw</STRONG>, stating that its
119 <STRONG>va_list</STRONG> definition requires <stdarg.h>.
122 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
123 In this implementation, <STRONG>vw_scanw</STRONG> and <STRONG>vwscanw</STRONG> are equivalent, to support
124 legacy applications. However, the latter (<STRONG>vwscanw</STRONG>) is obsolete:
126 <STRONG>o</STRONG> The XSI Curses standard, Issue 4 described these functions, noting
127 that the function <STRONG>vwscanw</STRONG> is marked TO BE WITHDRAWN, and is to be
128 replaced by a function <STRONG>vw_scanw</STRONG> using the <STRONG><stdarg.h></STRONG> interface.
130 <STRONG>o</STRONG> The Single Unix Specification, Version 2 states that <STRONG>vw_scanw</STRONG> is
131 preferred to <STRONG>vwscanw</STRONG> since the latter requires including
132 <STRONG><varargs.h></STRONG>, which cannot be used in the same file as <STRONG><stdarg.h></STRONG>.
133 This implementation uses <STRONG><stdarg.h></STRONG> for both, because that header
134 is included in <STRONG><curses.h</STRONG>>.
136 <STRONG>o</STRONG> X/Open Curses, Issue 5 (December 2007) marked <STRONG>vwscanw</STRONG> (along with
137 <STRONG>vwprintw</STRONG> and the termcap interface) as withdrawn.
139 Both XSI and The Single Unix Specification, Version 2 state that these
140 functions return <STRONG>ERR</STRONG> or <STRONG>OK</STRONG>.
142 <STRONG>o</STRONG> Since the underlying <STRONG>scanf(3)</STRONG> can return the number of items
143 scanned, and the SVr4 code was documented to use this feature, this
144 is probably an editing error which was introduced in XSI, rather
145 than being done intentionally.
147 <STRONG>o</STRONG> This implementation returns the number of items scanned, for
148 compatibility with SVr4 curses. As of 2018, NetBSD curses also
149 returns the number of items scanned. Both ncurses and NetBSD
150 curses call <STRONG>vsscanf</STRONG> to scan the string, which returns <STRONG>EOF</STRONG> on error.
152 <STRONG>o</STRONG> Portable applications should only test if the return value is <STRONG>ERR</STRONG>,
153 since the <STRONG>OK</STRONG> value (zero) is likely to be misleading.
155 One possible way to get useful results would be to use a "%n"
156 conversion at the end of the format string to ensure that something
160 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
161 <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>, <STRONG><A HREF="curs_printw.3x.html">curs_printw(3x)</A></STRONG>, <STRONG><A HREF="curs_termcap.3x.html">curs_termcap(3x)</A></STRONG>,
162 <STRONG>scanf(3)</STRONG>
166 ncurses 6.4 2023-10-07 <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG>
170 <li><a href="#h2-NAME">NAME</a></li>
171 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
172 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
173 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
174 <li><a href="#h2-HISTORY">HISTORY</a></li>
175 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
176 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>