curs_scanw(3) UNIX Programmer's Manual curs_scanw(3)
scanw, wscanw, mvscanw, mvwscanw, vwscanw, vw_scanw - con-
vert formatted input from a curses window
#include <curses.h>
int scanw(char *fmt, ...);
int wscanw(WINDOW *win, char *fmt, ...);
int mvscanw(int y, int x, char *fmt, ...);
int mvwscanw(WINDOW *win, int y, int x, char *fmt, ...);
int vw_scanw(WINDOW *win, char *fmt, va_list varglist);
int vwscanw(WINDOW *win, char *fmt, va_list varglist);
The scanw, wscanw and mvscanw routines are analogous to
scanf [see scanf(3)]. The effect of these routines is as
though wgetstr were called on the window, and the resulting
line used as input for sscanf(3). Fields which do not map
to a variable in the fmt field are lost.
The vwscanw and vw_scanw routines are analogous to vscanf.
They perform a wscanw using a variable argument list. The
third argument is a va_list, a pointer to a list of argu-
ments, as defined in <stdarg.h>.
vwscanw returns ERR on failure and an integer equal to the
number of fields scanned on success.
Applications may use the return value from the scanw,
wscanw, mvscanw and mvwscanw routines to determine the
number of fields which were mapped in the call.
The XSI Curses standard, Issue 4 describes these functions.
The function vwscanw is marked TO BE WITHDRAWN, and is to be
replaced by a function vw_scanw using the <stdarg.h> inter-
face. The Single Unix Specification, Version 2 states that
vw_scanw is preferred to vwscanw since the latter requires
including <varargs.h>, which cannot be used in the same file
as <stdarg.h>. This implementation uses <stdarg.h> for both,
because that header is included in <curses.h>.
Both XSI and The Single Unix Specification, Version 2 state
that these functions return ERR or OK. Since the underlying
scanf 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. Portable applications should only test
if the return value is ERR, since the OK value (zero) is
likely to be misleading. One possible way to get useful
MirBSD #10-current Printed 2022-12-23 1
curs_scanw(3) UNIX Programmer's Manual curs_scanw(3)
results would be to use a "%n" conversion at the end of the
format string to ensure that something was processed.
curses(3), curs_getstr(3), curs_printw(3), scanf(3)
MirBSD #10-current Printed 2022-12-23 2