unget_wch - Cheap VPS LLC

curs_get_wch


Section: Miscellaneous Library Functions (3X)
Updated:
Index
Return to Main Contents

 

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 input 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 newline (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 character 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 corresponding
KEY_
value defined
in
<curses.h>
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 function key value.
For this
reason, many terminals experience a delay between the time a user presses
the escape key and the time the escape is returned to the program.

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 undesirable results.

All functions except wget_wch and unget_wch
may be macros.
 

RETURN VALUES

When
get_wch,
wget_wch,
mvget_wch, and
mvwget_wch
functions 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.
Otherwise, the function returns
ERR.
 

SEE ALSO

curses(3X),
curs_getch(3X),
curs_ins_wch(3X),
curs_inopts(3X),
curs_move(3X),
curs_refresh(3X)



 

Index



NAME

SYNOPSIS

DESCRIPTION

NOTES

RETURN VALUES

SEE ALSO



Back to Top

PayPal Logo┬ęCheap VPS LLC - Leader of affordable VPS Hosting Services