.\"***************************************************************************
-.\" Copyright (c) 1998-2017,2018 Free Software Foundation, Inc. *
+.\" Copyright 2018-2019,2020 Thomas E. Dickey *
+.\" Copyright 1998-2010,2017 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 *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_scanw.3x,v 1.23 2018/04/07 20:56:03 tom Exp $
+.\" $Id: curs_scanw.3x,v 1.27 2020/03/15 00:14:30 tom Exp $
.TH curs_scanw 3X ""
+.ie \n(.g .ds `` \(lq
+.el .ds `` ``
+.ie \n(.g .ds '' \(rq
+.el .ds '' ''
.de bP
.ie n .IP \(bu 4
.el .IP \(bu 2
\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
+\fBscanf\fR [see \fBscanf\fR(3)].
+The effect of these routines is as though
\fBwgetstr\fR were called on the window, and the resulting line used as input
-for \fBsscanf\fR(3). Fields which do not map to a variable in the \fIfmt\fR
+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(3).
\fBmvscanw\fR and \fBmvwscanw\fR routines to determine the number of fields
which were mapped in the call.
.PP
-Functions with a "mv" prefix first perform a cursor movement using
+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 HISTORY
+While \fBscanw\fP 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.
+.PP
+SVr2 documented
+\fBscanw\fP,
+\fBwscanw\fP
+tersely as \*(``scanf through \fIstdscr\fP\*('' and
+tersely as \*(``scanf through \fIwin\fP\*('', respectively.
+.PP
+SVr3 added
+\fBmvscanw\fP, and
+\fBmvwscanw\fP, with a three-line summary saying that they were analogous
+to \fBscanf\fP(3),
+explaining that the string which would be output from \fBscanf\fP(3) would
+instead be output using \fBwaddstr\fP on the given window.
+SVr3 also added \fBvwscanw\fP, saying that the third parameter
+is a \fBva_list\fP, defined in <varargs.h>,
+and referring the reader to the manual pages for \fIvarargs\fP and
+\fIvprintf\fP for detailed descriptions.
+(Because the SVr3 documentation does not mention \fIvscanf\fP,
+that reference to \fIvprintf\fP may not be an error).
+.PP
+SVr4 added no new variations of \fBscanw\fP,
+but provided for using <varargs.h> or <stdarg.h> to define the \fBva_list\fP
+type.
+.PP
+X/Open Curses added \fBvw_scanw\fP to replace \fBvwscanw\fP,
+stating that its \fBva_list\fP definition requires <stdarg.h>.
.SH PORTABILITY
In this implementation, \fBvw_scanw\fP and \fBvwscanw\fP are equivalent,
to support legacy applications.
projects / ncurses.git / blobdiff