curs_get_wch 3x

curs_get_wch(3x)                                       curs_get_wch(3x)




NAME

       get_wch, wget_wch, mvget_wch, mvwget_wch, unget_wch - get
       (or push back) a wide character from curses terminal
       keyboard


SYNOPSIS

       #include <curses.h>

       int get_wch(wint_t *wch);
       int wget_wch(WINDOW *win, wint_t *wch);
       int mvget_wch(int y, int x, wint_t *wch);
       int mvwget_wch(WINDOW *win, int y, int x, wint_t *wch);
       int unget_wch(const wchar_t wch);


DESCRIPTION

       The get_wch, wget_wch, mvget_wch, and mvwget_wch functions
       read a character from the  terminal  associated  with  the
       current  or specified window.  In no-delay mode, if no in-
       put is waiting, the value ERR is returned.  In delay mode,
       the  program waits until the system passes text through to
       the program.  Depending on the setting of cbreak, this  is
       after one character (cbreak mode), or after the first new-
       line (nocbreak mode).  In  half-delay  mode,  the  program
       waits  until  the  user types a character or the specified
       timeout interval has elapsed.

       Unless noecho has been set, these routines echo the  char-
       acter into the designated window.

       If  the window is not a pad and has been moved or modified
       since the last call to wrefresh, wrefresh will  be  called
       before another character is read.

       If  keypad  is  enabled,  these  functions  respond to the
       pressing of a function key by setting the  object  pointed
       to by wch to the keycode assigned to the function key, and
       returning KEY_CODE_YES.  If a character (such  as  escape)
       that could be the beginning of a function key is received,
       curses sets a timer.  If the  remainder  of  the  sequence
       does  arrive  within  the  designated  time, curses passes
       through the character; otherwise, curses returns the func-
       tion  key  value.  For this reason, many terminals experi-
       ence a delay between the time a user  presses  the  escape
       key and the time the escape is returned to the program.

       The  keycodes  returned by these functions are the same as
       those returned by wgetch:

       o   The predefined function keys are listed in  <curses.h>
           as macros with values outside the range of 8-bit char-
           acters.  Their names begin with KEY_.

       o   Other (user-defined) function keys which  may  be  de-
           fined using define_key(3x) have no names, but also are
           expected to have values outside  the  range  of  8-bit
           characters.

       The  unget_wch function pushes the wide character wch back
       onto the head of the input queue, so the wide character is
       returned by the next call to get_wch.  The pushback of one
       character is guaranteed.  If the program  calls  unget_wch
       too many times without an intervening call to get_wch, the
       operation may fail.


NOTES

       The header  file  <curses.h>  automatically  includes  the
       header file <stdio.h>.

       Applications should not define the escape key by itself as
       a single-character function.

       When using get_wch, wget_wch,  mvget_wch,  or  mvwget_wch,
       applications should not use nocbreak mode and echo mode at
       the same time.  Depending on the state of the  tty  driver
       when  each character is typed, the program may produce un-
       desirable results.

       All functions except wget_wch and unget_wch may be macros.


RETURN VALUE

       When get_wch, wget_wch, mvget_wch,  and  mvwget_wch  func-
       tions  successfully report the pressing of a function key,
       they return KEY_CODE_YES.  When they successfully report a
       wide  character,  they  return OK.  Otherwise, they return
       ERR.

       Upon successful completion, unget_wch returns OK.   Other-
       wise, the function returns ERR.

       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.


SEE ALSO

       curses(3x),   curs_getch(3x),  curs_ins_wch(3x),  curs_in-
       opts(3x), curs_move(3x), curs_refresh(3x)



                                                       curs_get_wch(3x)