t
***************************************************************************
Copyright (c) 1998 Free Software Foundation, Inc. *
*
Permission is hereby granted, free of charge, to any person obtaining a *
copy of this software and associated documentation files (the *
"Software"), to deal in the Software without restriction, including *
without limitation the rights to use, copy, modify, merge, publish, *
distribute, distribute with modifications, sublicense, and/or sell *
copies of the Software, and to permit persons to whom the Software is *
furnished to do so, subject to the following conditions: *
*
The above copyright notice and this permission notice shall be included *
in all copies or substantial portions of the Software. *
*
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
*
Except as contained in this notice, the name(s) of the above copyright *
holders shall not be used in advertising or otherwise to promote the *
sale, use or other dealings in this Software without prior written *
authorization. *
***************************************************************************
$Id: curs_getch.3x,v 1.15 1998/11/29 01:04:26 Rick.Ohnemus Exp $
The has_key routine takes a key value from the above list, and
returns TRUE or FALSE according as the current terminal type recognizes
a key with that value.
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***************************************************************************
Copyright (c) 1998 Free Software Foundation, Inc. *
*
Permission is hereby granted, free of charge, to any person obtaining a *
copy of this software and associated documentation files (the *
"Software"), to deal in the Software without restriction, including *
without limitation the rights to use, copy, modify, merge, publish, *
distribute, distribute with modifications, sublicense, and/or sell *
copies of the Software, and to permit persons to whom the Software is *
furnished to do so, subject to the following conditions: *
*
The above copyright notice and this permission notice shall be included *
in all copies or substantial portions of the Software. *
*
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
*
Except as contained in this notice, the name(s) of the above copyright *
holders shall not be used in advertising or otherwise to promote the *
sale, use or other dealings in this Software without prior written *
authorization. *
***************************************************************************
$Id: curs_getch.3x,v 1.15 1998/11/29 01:04:26 Rick.Ohnemus Exp $
curs_getch 3X ""
NAME
getch, wgetch, mvgetch,
mvwgetch, ungetch - get (or push back) characters from
curses terminal keyboard
SYNOPSIS
#include <curses.h>
int getch(void);
int wgetch(WINDOW *win);
int mvgetch(int y, int x);
int mvwgetch(WINDOW *win, int y, int x);
int ungetch(int ch);
int has_key(int ch);
DESCRIPTION
The getch, wgetch, mvgetch and mvwgetch, routines read
a character from the 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 a character is typed or the
specified timeout has been reached.
If noecho has been set, then the character will also be echoed into the
designated window according to the following rules:
If the character is the current erase character, left arrow, or backspace,
the cursor is moved one space to the left and that screen position is erased
as if delch had been called.
If the character value is any other KEY_ define, the user is alerted
with a beep call.
Otherwise the character is simply output to the screen.
If the window is not a pad, and it has been moved or modified since the last
call to wrefresh, wrefresh will be called before another character
is read.
If keypad is TRUE, and a function key is pressed, the token for
that function key is returned instead of the raw characters. Possible function
keys are defined in <curses.h> as macros with values outside the range
of 8-bit characters whose names begin with KEY_. Thus, a variable
intended to hold the return value of a function key must be of short size or
larger.
When a character that could be the beginning of a function key is received
(which, on modern terminals, means an escape character), curses sets a
timer. If the remainder of the sequence does not come in within the designated
time, the character is passed through; otherwise, the function key value is
returned. For this reason, many terminals experience a delay between the time
a user presses the escape key and the escape is returned to the program.
The ungetch routine places ch back onto the input queue to be
returned by the next call to wgetch. Note that there is, in effect,
just one input queue for all windows.
Function Keys
The following function keys, defined in <curses.h>, might be returned by
getch if keypad has been enabled. Note that not all of these are
necessarily supported on any particular terminal.
| A1/up/A3 |
| left/B2/right |
| C1/down/C3 |
RETURN VALUE
All routines return the integer ERR upon failure and an integer value
other than ERR (OK in the case of ungetch()) upon successful
completion.
NOTES
Use of the escape key by a programmer for a single character function is
discouraged, as it will cause a delay of up to one second while the
keypad code looks for a following function-key sequence.
When using getch, wgetch, mvgetch, or
mvwgetch, nocbreak mode (nocbreak) and echo mode
(echo) should not be used at the same time. Depending on the
state of the tty driver when each character is typed, the program may
produce undesirable results.
Note that getch, mvgetch, and mvwgetch may be macros.
Historically, the set of keypad macros was largely defined by the extremely
function-key-rich keyboard of the AT&T 7300, aka 3B1, aka Safari 4. Modern
personal computers usually have only a small subset of these. IBM PC-style
consoles typically support little more than KEY_UP, KEY_DOWN,
KEY_LEFT, KEY_RIGHT, KEY_HOME, KEY_END,
KEY_NPAGE, KEY_PPAGE, and function keys 1 through 12. The Ins key
is usually mapped to KEY_IC.
PORTABILITY
The *get* functions are described in the XSI Curses standard, Issue 4. They
read single-byte characters only. The standard specifies that they return
ERR on failure, but specifies no error conditions.
The echo behavior of these functions on input of KEY_ or backspace
characters was not specified in the SVr4 documentation. This description is
adopted from the XSI Curses standard.
The behavior of getch and friends in the presence of handled signals is
unspecified in the SVr4 and XSI Curses documentation. Under historical curses
implementations, it varied depending on whether the operating system's
implementation of handled signal receipt interrupts a read(2) call in
progress or not, and also (in some implementations) depending on whether an
input timeout or non-blocking mode hsd been set.
Programmers concerned about portability should be prepared for either of two
cases: (a) signal receipt does not interrupt getch; (b) signal receipt
interrupts getch and causes it to return ERR with errno set to
EINTR. Under the ncurses implementation, handled signals never
interrupt getch.
The has_key function is unique to ncurses. We recommend that
any code using it be conditionalized on the NCURSES_VERSION feature macro.
SEE ALSO
curses(3X),
curs_inopts(3X),
curs_mouse(3X),
curs_move(3X),
curs_refresh(3X).
resizeterm(3X).
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