# curs_scanw 3x

    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(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(3).   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 determine the  number  of  fields  which  were
           mapped in the call.

           Functions  with  a  "mv"  prefix  first perform a cursor movement using
           wmove, and return an error if the position is outside the window, or if
           the window pointer is null.

## PORTABILITY

           The  XSI Curses standard, Issue 4 describes these functions.  The func-
           tion vwscanw is marked TO BE WITHDRAWN, and is  to  be  replaced  by  a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(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.   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(3)

                                                                    curs_scanw(3x)