# curs_scanw 3x

    curs_scanw(3x)                                           curs_scanw(3x)

## NAME

           scanw, wscanw, mvscanw, mvwscanw, vwscanw, vw_scanw - con-
           vert 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  result-
           ing 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>.

## 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  move-
           ment  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  func-
           tions.   The  function  vwscanw is marked TO BE WITHDRAWN,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, Ver-
           sion 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 applica-
           tions should only test if the return value is  ERR,  since
           the  OK value (zero) is likely to be misleading.  One pos-
           sible 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)