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diff --git a/doc/html/man/curs_scanw.3x.html b/doc/html/man/curs_scanw.3x.html index 91b68292143b..d0b9b7947d47 100644 --- a/doc/html/man/curs_scanw.3x.html +++ b/doc/html/man/curs_scanw.3x.html @@ -1,6 +1,6 @@ -<!-- +<!-- **************************************************************************** - * Copyright 2018-2019,2020 Thomas E. Dickey * + * Copyright 2018-2023,2024 Thomas E. Dickey * * Copyright 1998-2010,2017 Free Software Foundation, Inc. * * * * Permission is hereby granted, free of charge, to any person obtaining a * @@ -27,28 +27,28 @@ * sale, use or other dealings in this Software without prior written * * authorization. * **************************************************************************** - * @Id: curs_scanw.3x,v 1.28 2020/10/24 09:29:26 tom Exp @ + * @Id: curs_scanw.3x,v 1.53 2024/04/20 19:18:18 tom Exp @ --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> <HTML> <HEAD> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts"> -<TITLE>curs_scanw 3x</TITLE> +<TITLE>curs_scanw 3x 2024-04-20 ncurses 6.5 Library calls</TITLE> <link rel="author" href="mailto:bug-ncurses@gnu.org"> -<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> + </HEAD> <BODY> -<H1 class="no-header">curs_scanw 3x</H1> +<H1 class="no-header">curs_scanw 3x 2024-04-20 ncurses 6.5 Library calls</H1> <PRE> -<STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG> <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG> +<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> </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE> - <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG>, <STRONG>mvscanw</STRONG>, <STRONG>mvwscanw</STRONG>, <STRONG>vwscanw</STRONG>, <STRONG>vw_scanw</STRONG> - convert formatted - input from a <STRONG>curses</STRONG> window + <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG>, <STRONG>mvscanw</STRONG>, <STRONG>mvwscanw</STRONG>, <STRONG>vwscanw</STRONG>, <STRONG>vw_scanw</STRONG> - read formatted + input from a <EM>curses</EM> window </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> @@ -61,109 +61,125 @@ <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> - /* obsolete */ + <EM>/*</EM> <EM>obsolete</EM> <EM>*/</EM> <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> </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE> - The <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG> and <STRONG>mvscanw</STRONG> routines are analogous to <STRONG>scanf</STRONG> [see - <STRONG>scanf(3)</STRONG>]. The effect of these routines is as though <STRONG>wgetstr</STRONG> were - called on the window, and the resulting line used as input for - <STRONG>sscanf(3)</STRONG>. Fields which do not map to a variable in the <EM>fmt</EM> field are - lost. + <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG>, <STRONG>mvscanw</STRONG>, and <STRONG>mvwscanw</STRONG> are analogous to <STRONG>scanf(3)</STRONG>. In + effect, they call <STRONG><A HREF="curs_getstr.3x.html">wgetstr(3x)</A></STRONG> with <EM>win</EM> (or <STRONG>stdscr</STRONG>) as its first + argument, then attempt conversion of the resulting string with + <STRONG>vsscanf(3)</STRONG>. Fields in the string that do not map to a variable in the + <EM>fmt</EM> parameter are discarded. - The <STRONG>vwscanw</STRONG> and <STRONG>vw_scanw</STRONG> routines are analogous to <STRONG>vscanf(3)</STRONG>. They - perform a <STRONG>wscanw</STRONG> using a variable argument list. The third argument is - a <EM>va</EM><STRONG>_</STRONG><EM>list</EM>, a pointer to a list of arguments, as defined in <STRONG><stdarg.h></STRONG>. + <STRONG>vwscanw</STRONG> and <STRONG>vw_scanw</STRONG> are analogous to <STRONG>vscanf(3)</STRONG>, and perform a <STRONG>wscanw</STRONG> + using a variable argument list. The third argument is a <EM>va</EM><STRONG>_</STRONG><EM>list</EM>, a + pointer to a list of arguments, as defined in <EM>stdarg.h</EM>. </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE> - <STRONG>vwscanw</STRONG> returns <STRONG>ERR</STRONG> on failure and an integer equal to the number of - fields scanned on success. + These functions return <STRONG>ERR</STRONG> upon failure and otherwise a count of + successful conversions; this quantity may be zero. - Applications may use the return value from the <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG>, <STRONG>mvscanw</STRONG> - and <STRONG>mvwscanw</STRONG> routines to determine the number of fields which were - mapped in the call. + In <EM>ncurses</EM>, failure occurs if <STRONG>vsscanf(3)</STRONG> returns <STRONG>EOF</STRONG>, or if the window + pointer <EM>win</EM> is null. - Functions with a "mv" prefix first perform a cursor movement using - <STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if - the window pointer is null. + Functions prefixed with "mv" first perform cursor movement and fail if + the position (<EM>y</EM>, <EM>x</EM>) is outside the window boundaries. -</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE> - While <STRONG>scanw</STRONG> was implemented in 4BSD, none of the BSD releases used it - until 4.4BSD (in a game). That early version of curses was before the - ANSI C standard. It did not use <varargs.h>, though that was - available. In 1991 (a couple of years after SVr4 was generally - available, and after the C standard was published), other developers - updated the library, using <stdarg.h> internally in 4.4BSD curses. - Even with this improvement, BSD curses did not use function prototypes - (or even declare functions) in the <curses.h> header until 1992. - - SVr2 documented <STRONG>scanw</STRONG>, <STRONG>wscanw</STRONG> tersely as "scanf through <EM>stdscr</EM>" and - tersely as "scanf through <EM>win</EM>", respectively. - - SVr3 added <STRONG>mvscanw</STRONG>, and <STRONG>mvwscanw</STRONG>, with a three-line summary saying that - they were analogous to <STRONG>scanf(3)</STRONG>, explaining that the string which would - be output from <STRONG>scanf(3)</STRONG> would instead be output using <STRONG>waddstr</STRONG> on the - given window. SVr3 also added <STRONG>vwscanw</STRONG>, saying that the third parameter - is a <STRONG>va_list</STRONG>, defined in <varargs.h>, and referring the reader to the - manual pages for <EM>varargs</EM> and <EM>vprintf</EM> for detailed descriptions. - (Because the SVr3 documentation does not mention <EM>vscanf</EM>, that reference - to <EM>vprintf</EM> may not be an error). - - SVr4 added no new variations of <STRONG>scanw</STRONG>, but provided for using - <varargs.h> or <stdarg.h> to define the <STRONG>va_list</STRONG> type. - - X/Open Curses added <STRONG>vw_scanw</STRONG> to replace <STRONG>vwscanw</STRONG>, stating that its - <STRONG>va_list</STRONG> definition requires <stdarg.h>. +</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE> + No wide character counterpart functions are defined by the "wide" + <EM>ncurses</EM> configuration nor by any standard. They are unnecessary: to + retrieve and convert a wide-character string from a <EM>curses</EM> terminal + keyboard, use these functions with the <STRONG>scanf(3)</STRONG> conversions "%lc" and + "%ls" for wide characters and strings, respectively. + + <EM>ncurses</EM> implements <STRONG>vsscanf(3)</STRONG> internally if it is unavailable when the + library is configured. </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE> - In this implementation, <STRONG>vw_scanw</STRONG> and <STRONG>vwscanw</STRONG> are equivalent, to support - legacy applications. However, the latter (<STRONG>vwscanw</STRONG>) is obsolete: + X/Open Curses, Issue 4 describes these functions. It specifies no + error conditions for them. + + <EM>ncurses</EM> defines <STRONG>vw_scanw</STRONG> and <STRONG>vwscanw</STRONG> identically to support legacy + applications. However, the latter is obsolete. - <STRONG>o</STRONG> The XSI Curses standard, Issue 4 described these functions, noting - that the function <STRONG>vwscanw</STRONG> is marked TO BE WITHDRAWN, and is to be - replaced by a function <STRONG>vw_scanw</STRONG> using the <STRONG><stdarg.h></STRONG> interface. + <STRONG>o</STRONG> X/Open Curses, Issue 4 Version 2 (1996), marked <STRONG>vwscanw</STRONG> as + requiring <EM>varargs.h</EM> and "TO BE WITHDRAWN", and specified <STRONG>vw_scanw</STRONG> + using the <EM>stdarg.h</EM> interface. - <STRONG>o</STRONG> The Single Unix Specification, Version 2 states that <STRONG>vw_scanw</STRONG> is - preferred to <STRONG>vwscanw</STRONG> since the latter requires including - <STRONG><varargs.h></STRONG>, which cannot be used in the same file as <STRONG><stdarg.h></STRONG>. - This implementation uses <STRONG><stdarg.h></STRONG> for both, because that header - is included in <STRONG><curses.h</STRONG>>. + <STRONG>o</STRONG> X/Open Curses, Issue 5, Draft 2 (December 2007) marked <STRONG>vwscanw</STRONG> + (along with <STRONG>vwscanw</STRONG> and the <EM>termcap</EM> interface) as withdrawn. After + incorporating review comments, this became X/Open Curses, Issue 7 + (2009). - <STRONG>o</STRONG> X/Open Curses, Issue 5 (December 2007) marked <STRONG>vwscanw</STRONG> (along with - <STRONG>vwprintw</STRONG> and the termcap interface) as withdrawn. + <STRONG>o</STRONG> <EM>ncurses</EM> provides <STRONG>vwscanw</STRONG>, but marks it as deprecated. - Both XSI and The Single Unix Specification, Version 2 state that these - functions return <STRONG>ERR</STRONG> or <STRONG>OK</STRONG>. + X/Open Curses Issues 4 and 7 both state that these functions return <STRONG>ERR</STRONG> + or <STRONG>OK</STRONG>. This is likely an erratum. - <STRONG>o</STRONG> Since the underlying <STRONG>scanf(3)</STRONG> can return the number of items - scanned, and the SVr4 code was documented to use this feature, this - is probably an editing error which was introduced in XSI, rather - than being done intentionally. + <STRONG>o</STRONG> Since the underlying <STRONG>scanf(3)</STRONG> returns the number of successful + conversions, and SVr4 <EM>curses</EM> was documented to use this feature, + this may have been an editorial solecism introduced by X/Open, + rather than an intentional change. - <STRONG>o</STRONG> This implementation returns the number of items scanned, for - compatibility with SVr4 curses. As of 2018, NetBSD curses also - returns the number of items scanned. Both ncurses and NetBSD - curses call <STRONG>vsscanf</STRONG> to scan the string, which returns <STRONG>EOF</STRONG> on error. + <STRONG>o</STRONG> This implementation retains compatibility with SVr4 <EM>curses</EM>. As of + 2018, NetBSD <EM>curses</EM> also returns the number of successful + conversions. Both <EM>ncurses</EM> and NetBSD <EM>curses</EM> call <STRONG>vsscanf(3)</STRONG> to + scan the string, which returns <STRONG>EOF</STRONG> on error. - <STRONG>o</STRONG> Portable applications should only test if the return value is <STRONG>ERR</STRONG>, - since the <STRONG>OK</STRONG> value (zero) is likely to be misleading. + <STRONG>o</STRONG> Portable applications should test only if the return value is <STRONG>ERR</STRONG>, + and not compare it to <STRONG>OK</STRONG>, since that value (zero) might be + misleading. + + One portable way to get useful results would be to use a "%n" + conversion at the end of the format string, and check the value of + the corresponding variable to determine how many conversions + succeeded. + + +</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE> + <STRONG>scanw</STRONG> was implemented in 4BSD (November 1980); that early version of + <EM>curses</EM> preceded the ANSI C standard of 1989. The function was unused + in Berkeley distributions for over ten years, until 4.4BSD, which + employed it in a game. The 4BSD <STRONG>scanw</STRONG> did not use <EM>varargs.h</EM>, though + that had been available since Seventh Edition Unix (1979). In 1991 (a + couple of years after SVr4 was generally available, and after the C + standard was published), other developers updated the library, using + <EM>stdarg.h</EM> internally in 4.4BSD <EM>curses</EM>. Even with this improvement, BSD + <EM>curses</EM> did not use function prototypes (nor even declare functions) in + <EM>curses.h</EM> until 1992. - One possible way to get useful results would be to use a "%n" - conversion at the end of the format string to ensure that something - was processed. + SVr2 (1984) documented <STRONG>scanw</STRONG> and <STRONG>wscanw</STRONG> tersely as "scanf through + <STRONG>stdscr</STRONG>" and "scanf through <EM>win</EM>", respectively. + + SVr3 (1987) added <STRONG>mvscanw</STRONG>, and <STRONG>mvwscanw</STRONG>, stating + + "[t]hese routines correspond to <STRONG>scanf(3S)</STRONG>, as do their arguments + and return values. <STRONG>wgetstr</STRONG>() is called on the window, and the + resulting line is used as input for the scan." + + SVr3 also implemented <STRONG>vwscanw</STRONG>, describing its third parameter as a + <EM>va</EM><STRONG>_</STRONG><EM>list</EM>, defined in <EM>varargs.h</EM>, and referred the reader to the manual + pages for <EM>varargs</EM> and <EM>vprintf</EM> for detailed descriptions. (Because the + SVr3 documentation does not mention <EM>vscanf</EM>, the reference to <EM>vprintf</EM> + might not be an error). + + SVr4 (1989) introduced no new variations of <EM>scanw</EM>, but provided for + using either <EM>varargs.h</EM> or <EM>stdarg.h</EM> to define the <EM>va</EM><STRONG>_</STRONG><EM>list</EM> type. + + X/Open Curses, Issue 4 (1995), defined <EM>vw</EM><STRONG>_</STRONG><EM>scanw</EM> to replace <EM>vwscanw</EM>, + stating that its <EM>va</EM><STRONG>_</STRONG><EM>list</EM> type is defined in <EM>stdarg.h</EM>. </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE> - <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>, - <STRONG>scanf(3)</STRONG>. + <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>scanf(3)</STRONG>, <STRONG>vscanf(3)</STRONG> - <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG> +ncurses 6.5 2024-04-20 <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG> </PRE> <div class="nav"> <ul> @@ -171,8 +187,9 @@ <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li> <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li> <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li> -<li><a href="#h2-HISTORY">HISTORY</a></li> +<li><a href="#h2-NOTES">NOTES</a></li> <li><a href="#h2-PORTABILITY">PORTABILITY</a></li> +<li><a href="#h2-HISTORY">HISTORY</a></li> <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li> </ul> </div> |