ncurses 6.1 - patch 20180407

[ncurses.git] / man / curs_scanw.3x

diff --git a/man/curs_scanw.3x b/man/curs_scanw.3x
index 5e9ba0bd08714f010c03065e980dd0a1ab356304..8e843e9c5347d15374dbc60ddcd29612088b3f2c 100644 (file)
--- a/man/curs_scanw.3x
+++ b/man/curs_scanw.3x
@@ -1,5 +1,5 @@
 .\"***************************************************************************
 .\"***************************************************************************

-.\" Copyright (c) 1998-2006,2010 Free Software Foundation, Inc.              *
+.\" Copyright (c) 1998-2017,2018 Free Software Foundation, Inc.              *

 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *
 .\" copy of this software and associated documentation files (the            *
 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *
 .\" copy of this software and associated documentation files (the            *


@@ -26,8 +26,12 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: curs_scanw.3x,v 1.16 2010/08/14 23:29:16 tom Exp $
+.\" $Id: curs_scanw.3x,v 1.23 2018/04/07 20:56:03 tom Exp $

 .TH curs_scanw 3X ""
 .TH curs_scanw 3X ""

+.de bP
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
+..

 .SH NAME
 \fBscanw\fR,
 \fBwscanw\fR,
 .SH NAME
 \fBscanw\fR,
 \fBwscanw\fR,


@@ -37,17 +41,19 @@
 .SH SYNOPSIS
 \fB#include <curses.h>\fR
 .sp
 .SH SYNOPSIS
 \fB#include <curses.h>\fR
 .sp

-\fBint scanw(char *fmt, ...);\fR
+\fBint scanw(const char *fmt, ...);\fR

 .br
 .br

-\fBint wscanw(WINDOW *win, char *fmt, ...);\fR
+\fBint wscanw(WINDOW *win, const char *fmt, ...);\fR

 .br
 .br

-\fBint mvscanw(int y, int x, char *fmt, ...);\fR
+\fBint mvscanw(int y, int x, const char *fmt, ...);\fR

 .br
 .br

-\fBint mvwscanw(WINDOW *win, int y, int x, char *fmt, ...);\fR
+\fBint mvwscanw(WINDOW *win, int y, int x, const char *fmt, ...);\fR

 .br
 .br

-\fBint vw_scanw(WINDOW *win, char *fmt, va_list varglist);\fR
+\fBint vw_scanw(WINDOW *win, const char *fmt, va_list varglist);\fR
+.sp
+/* obsolete */

 .br
 .br

-\fBint vwscanw(WINDOW *win, char *fmt, va_list varglist);\fR
+\fBint vwscanw(WINDOW *win, const char *fmt, va_list varglist);\fR

 .SH DESCRIPTION
 The \fBscanw\fR, \fBwscanw\fR and \fBmvscanw\fR routines are analogous to
 \fBscanf\fR [see \fBscanf\fR(3)].  The effect of these routines is as though
 .SH DESCRIPTION
 The \fBscanw\fR, \fBwscanw\fR and \fBmvscanw\fR routines are analogous to
 \fBscanf\fR [see \fBscanf\fR(3)].  The effect of these routines is as though


@@ -55,7 +61,7 @@ The \fBscanw\fR, \fBwscanw\fR and \fBmvscanw\fR routines are analogous to
 for \fBsscanf\fR(3).  Fields which do not map to a variable in the \fIfmt\fR
 field are lost.
 .PP
 for \fBsscanf\fR(3).  Fields which do not map to a variable in the \fIfmt\fR
 field are lost.
 .PP

-The \fBvwscanw\fR and \fBvw_scanw\fR routines are analogous to \fBvscanf\fR.
+The \fBvwscanw\fR and \fBvw_scanw\fR routines are analogous to \fBvscanf\fR(3).

 They perform a \fBwscanw\fR using a variable argument list.
 The third argument is a \fIva_list\fR,
 a pointer to a list of arguments, as defined in \fB<stdarg.h>\fR.
 They perform a \fBwscanw\fR using a variable argument list.
 The third argument is a \fIva_list\fR,
 a pointer to a list of arguments, as defined in \fB<stdarg.h>\fR.


@@ -71,31 +77,48 @@ Functions with a "mv" prefix first perform a cursor movement using
 \fBwmove\fP, and return an error if the position is outside the window,
 or if the window pointer is null.
 .SH PORTABILITY
 \fBwmove\fP, and return an error if the position is outside the window,
 or if the window pointer is null.
 .SH PORTABILITY

-The XSI Curses standard, Issue 4 describes these functions.  The function
+In this implementation, \fBvw_scanw\fP and \fBvwscanw\fP are equivalent,
+to support legacy applications.
+However, the latter (\fBvwscanw\fP) is obsolete:
+.bP
+The XSI Curses standard, Issue 4 described these functions,
+noting that the function

 \fBvwscanw\fR is marked TO BE WITHDRAWN, and is to be replaced by a function
 \fBvw_scanw\fR using the \fB<stdarg.h>\fR interface.
 \fBvwscanw\fR is marked TO BE WITHDRAWN, and is to be replaced by a function
 \fBvw_scanw\fR using the \fB<stdarg.h>\fR interface.

+.bP

 The Single Unix Specification, Version 2 states that
 \fBvw_scanw\fR  is preferred to \fBvwscanw\fR since the latter requires
 including \fB<varargs.h>\fR, which
 cannot be used in the same file as \fB<stdarg.h>\fR.
 This implementation uses \fB<stdarg.h>\fR for both, because that header
 is included in \fB<curses.h\fR>.
 The Single Unix Specification, Version 2 states that
 \fBvw_scanw\fR  is preferred to \fBvwscanw\fR since the latter requires
 including \fB<varargs.h>\fR, which
 cannot be used in the same file as \fB<stdarg.h>\fR.
 This implementation uses \fB<stdarg.h>\fR for both, because that header
 is included in \fB<curses.h\fR>.

+.bP
+X/Open Curses, Issue 5 (December 2007) marked \fBvwscanw\fP (along with
+\fBvwprintw\fP and the termcap interface) as withdrawn.

 .LP
 Both XSI and The Single Unix Specification, Version 2 state that these
 .LP
 Both XSI and The Single Unix Specification, Version 2 state that these

-functions return ERR or OK.
-Since the underlying \fBscanf\fR can return the number of items scanned,
+functions return \fBERR\fP or \fBOK\fP.
+.bP
+Since the underlying \fBscanf\fR(3) 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.
 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.

-Portable applications should only test if the return value is ERR,
-since the OK value (zero) is likely to be misleading.
+.bP
+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 \fBvsscanf\fP to scan the string,
+which returns \fBEOF\fP on error.
+.bP
+Portable applications should only test if the return value is \fBERR\fP,
+since the \fBOK\fP value (zero) is likely to be misleading.
+.IP

 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.
 .SH SEE ALSO
 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.
 .SH SEE ALSO

-\fBcurses\fR(3X), \fBcurs_getstr\fR(3X), \fBcurs_printw\fR(3X), \fBscanf\fR(3)
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+.na
+\fBcurses\fR(3X),
+\fBcurs_getstr\fR(3X),
+\fBcurs_printw\fR(3X),
+\fBcurs_termcap\fP(3X),
+\fBscanf\fR(3).