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curs_scanw(3)                                                  curs_scanw(3)


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       tion  vwscanw  is  marked  TO  BE WITHDRAWN, and is to be replaced by a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


ncurses 6.0 - Generated Sat May 6 18:50:17 CDT 2017
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