'\" t
-.\" $Id: curs_getch.3x,v 1.12 1997/12/13 22:39:05 tom Exp $
+.\"***************************************************************************
+.\" Copyright (c) 1998-2005,2006 Free Software Foundation, Inc. *
+.\" *
+.\" Permission is hereby granted, free of charge, to any person obtaining a *
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+.\" 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 1.30 2006/12/02 17:02:53 tom Exp $
.TH curs_getch 3X ""
+.na
+.hy 0
.SH NAME
-\fBgetch\fR, \fBwgetch\fR, \fBmvgetch\fR,
-\fBmvwgetch\fR, \fBungetch\fR - get (or push back) characters from
-\fBcurses\fR terminal keyboard
+\fBgetch\fR,
+\fBwgetch\fR,
+\fBmvgetch\fR,
+\fBmvwgetch\fR,
+\fBungetch\fR,
+\fBhas_key\fR \- get (or push back) characters from \fBcurses\fR terminal keyboard
+.ad
+.hy
.SH SYNOPSIS
\fB#include <curses.h>\fR
-
+.PP
\fBint getch(void);\fR
.br
\fBint wgetch(WINDOW *win);\fR
.br
.SH DESCRIPTION
The \fBgetch\fR, \fBwgetch\fR, \fBmvgetch\fR and \fBmvwgetch\fR, routines read
-a character from the window. In no-delay mode, if no input is waiting, the
-value \fBERR\fR is returned. In delay mode, the program waits until the system
-passes text through to the program. Depending on the setting of \fBcbreak\fR,
-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
+a character from the window.
+In no-delay mode, if no input is waiting, the value \fBERR\fR is returned.
+In delay mode, the program waits until the system
+passes text through to the program.
+Depending on the setting of \fBcbreak\fR,
+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 \fBnoecho\fR has been set, then the character will also be echoed into the
+.PP
+Unless \fBnoecho\fR 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
If the character value is any other \fBKEY_\fR define, the user is alerted
with a \fBbeep\fR call.
Otherwise the character is simply output to the screen.
-
+.PP
If the window is not a pad, and it has been moved or modified since the last
call to \fBwrefresh\fR, \fBwrefresh\fR will be called before another character
is read.
-
+.PP
If \fBkeypad\fR is \fBTRUE\fR, and a function key is pressed, the token for
-that function key is returned instead of the raw characters. Possible function
+that function key is returned instead of the raw characters.
+Possible function
keys are defined in \fB<curses.h>\fR as macros with values outside the range
-of 8-bit characters whose names begin with \fBKEY_.\fR Thus, a variable
+of 8-bit characters whose names begin with \fBKEY_\fR. Thus, a variable
intended to hold the return value of a function key must be of short size or
larger.
-
+.PP
When a character that could be the beginning of a function key is received
-(which, on modern terminals, means an escape character), \fBcurses\fR 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
+(which, on modern terminals, means an escape character),
+\fBcurses\fR 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.
-
+.PP
The \fBungetch\fR routine places \fIch\fR back onto the input queue to be
-returned by the next call to \fBwgetch\fR. Note that there is, in effect,
-just one input queue for all windows.
-
+returned by the next call to \fBwgetch\fR.
+There is just one input queue for all windows.
+.PP
.SS Function Keys
The following function keys, defined in \fB<curses.h>\fR, might be returned by
-\fBgetch\fR if \fBkeypad\fR has been enabled. Note that not all of these are
+\fBgetch\fR if \fBkeypad\fR has been enabled.
+Note that not all of these are
necessarily supported on any particular terminal.
.sp
.TS
l l
l l .
\fIName\fR/\fIKey\fR \fIname\fR
-
KEY_BREAK/Break key
KEY_DOWN/The four arrow keys ...
KEY_UP
KEY_SRESET/Soft (partial) reset
KEY_RESET/Reset or hard reset
KEY_PRINT/Print or copy
-KEY_LL/Home down or bottom (lower left).
+KEY_LL/Home down or bottom (lower left)
KEY_A1/Upper left of keypad
KEY_A3/Upper right of keypad
KEY_B2/Center of keypad
KEY_SUSPEND/Suspend key
KEY_UNDO/Undo key
.TE
-
+.PP
Keypad is arranged like this:
.sp
.TS
.TE
.sp
The \fBhas_key\fR 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.
-
+returns TRUE or FALSE according to whether
+the current terminal type recognizes a key with that value.
+Note that a few values do not correspond to a real key,
+e.g., \fBKEY_RESIZE\fP and \fBKEY_MOUSE\fP.
+See \fBresizeterm\fR(3X) for more details about \fBKEY_RESIZE\fP, and
+\fBcurs_mouse\fR(3X) for a discussion of \fBKEY_MOUSE\fP.
+.PP
.SH RETURN VALUE
All routines return the integer \fBERR\fR upon failure and an integer value
other than \fBERR\fR (\fBOK\fR in the case of ungetch()) upon successful
completion.
+.RS
+.TP 5
+\fBungetch\fP
+returns an error
+if there is no more room in the FIFO.
+.TP 5
+\fBwgetch\fP
+returns an error
+if the window pointer is null, or
+if its timeout expires without having any data.
+.RE
.SH 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.
-
+.PP
+Note that some keys may be the same as commonly used control
+keys, e.g., \fBKEY_ENTER\fP versus control/M, \fBKEY_BACKSPACE\fP versus control/H.
+Some curses implementations may differ according to whether they
+treat these control keys specially (and ignore the terminfo), or
+use the terminfo definitions.
+\fBNcurses\fR uses the terminfo definition.
+If it says that \fBKEY_ENTER\fP is control/M,
+\fBgetch\fR will return \fBKEY_ENTER\fP
+when you press control/M.
+.PP
When using \fBgetch\fR, \fBwgetch\fR, \fBmvgetch\fR, or
\fBmvwgetch\fR, nocbreak mode (\fBnocbreak\fR) and echo mode
-(\fBecho\fR) should not be used at the same time. Depending on the
+(\fBecho\fR) 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.
-
+.PP
Note that \fBgetch\fR, \fBmvgetch\fR, and \fBmvwgetch\fR may be macros.
-
+.PP
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
+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 \fBKEY_UP\fR, \fBKEY_DOWN\fR,
\fBKEY_LEFT\fR, \fBKEY_RIGHT\fR, \fBKEY_HOME\fR, \fBKEY_END\fR,
-\fBKEY_NPAGE\fR, \fBKEY_PPAGE\fR, and function keys 1 through 12. The Ins key
+\fBKEY_NPAGE\fR, \fBKEY_PPAGE\fR, and function keys 1 through 12.
+The Ins key
is usually mapped to \fBKEY_IC\fR.
.SH 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
+The *get* functions are described in the XSI Curses standard, Issue 4.
+They
+read single-byte characters only.
+The standard specifies that they return
\fBERR\fR on failure, but specifies no error conditions.
-
+.PP
The echo behavior of these functions on input of \fBKEY_\fR or backspace
-characters was not specified in the SVr4 documentation. This description is
+characters was not specified in the SVr4 documentation.
+This description is
adopted from the XSI Curses standard.
-
+.PP
The behavior of \fBgetch\fR and friends in the presence of handled signals is
-unspecified in the SVr4 and XSI Curses documentation. Under historical curses
+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 \fBread\fR(2) call in
progress or not, and also (in some implementations) depending on whether an
-input timeout or non-blocking mode hsd been set.
-
+input timeout or non-blocking mode has been set.
+.PP
Programmers concerned about portability should be prepared for either of two
cases: (a) signal receipt does not interrupt \fBgetch\fR; (b) signal receipt
interrupts \fBgetch\fR and causes it to return ERR with \fBerrno\fR set to
-\fBEINTR\fR. Under the \fBncurses\fR implementation, handled signals never
+\fBEINTR\fR.
+Under the \fBncurses\fR implementation, handled signals never
interrupt \fBgetch\fR.
-
-The \fBhas_key\fR function is unique to \fBncurses\fR. We recommend that
+.PP
+The \fBhas_key\fR function is unique to \fBncurses\fR.
+We recommend that
any code using it be conditionalized on the \fBNCURSES_VERSION\fR feature macro.
.SH SEE ALSO
\fBcurses\fR(3X),
\fBcurs_inopts\fR(3X),
\fBcurs_mouse\fR(3X),
\fBcurs_move\fR(3X),
-\fBcurs_refresh\fR(3X).
+\fBcurs_refresh\fR(3X),
\fBresizeterm\fR(3X).
+.PP
+Comparable functions in the wide-character (ncursesw) library are
+described in
+\fBcurs_get_wch\fR(3X).
.\"#
.\"# The following sets edit modes for GNU EMACS
.\"# Local Variables:
projects / ncurses.git / blobdiff