curs_scanw 3x

curs_scanw(3x)                                                  curs_scanw(3x)


       scanw, wscanw, mvscanw, mvwscanw, vwscanw, vw_scanw - convert 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

       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>.


       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.


       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       tion vwscanw is marked TO BE WITHDRAWN, and is  to  be  replaced  by  a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.


       curses(3x), curs_getstr(3x), curs_printw(3x), scanf(3)