curs_scanw(3X) curs_scanw(3X)
NAME
scanw, wscanw, mvscanw, mvwscanw, vwscanw, vw_scanw - convert formatted input from a curses window
SYNOPSIS
#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);
DESCRIPTION
The scanw, wscanw and mvscanw routines are analogous to scanf [see scanf(3S)]. 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 arguments, as defined in
<stdarg.h>.
RETURN VALUE
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 deter-mine determine
mine the number of fields which were mapped in the call.
PORTABILITY
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WITHDRAWN, and is to be replaced by a function vw_scanw using the 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> interface. 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 results would be to use a
"%n" conversion at the end of the format string to ensure that something was processed.
SEE ALSO
curses(3X), curs_getstr(3X), curs_printw(3X), scanf(3S)
curs_scanw(3X)
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