GETCH(3XCURSES) X/Open Curses Library Functions GETCH(3XCURSES)

NAME

getch, wgetch, mvgetch, mvwgetch - get a single-byte character from
the terminal

SYNOPSIS

cc [ flag... ] file... -I /usr/xpg4/include -L /usr/xpg4/lib \
-R /usr/xpg4/lib -lcurses [ library... ]

c89 [ flag... ] file... -lcurses [ library... ]

#include <curses.h>

int getch(void);


int wgetch(WINDOW *win);


int mvgetch(int y, int x);


int mvwgetch(WINDOW *win, int y, int x);

PARAMETERS

win
Is a pointer to the window associated with the terminal from
which the character is to be read.


y
Is the y (row) coordinate for the position of the character to
be read.


x
Is the x (column) coordinate for the position of the character
to be read.

DESCRIPTION

These functions read a single-byte character from the terminal
associated with the current or specified window. The results are
unspecified if the input is not a single-byte character. If
keypad(3XCURSES) is enabled, these functions respond to the pressing
of a function key by returning the corresponding KEY_ value defined
in <curses.h>


Processing of terminal input is subject to the general rules
described on the keypad(3XCURSES) manual page.


If echoing is enabled, then the character is echoed as though it were
provided as an input argument to addch(3XCURSES), except for the
following characters:

<backspace>
The input is interpreted as follows: unless the
cursor already was in column 0, <backspace> moves
the cursor one column toward the start of the
current line and any characters after the
<backspace> are added or inserted starting there.
The character at the resulting cursor position it
then deleted as though delch(3XCURSES) were called,
except that if the cursor was originally in the
first column of the line, the user is alerted as
though beep(3XCURSES) were called.


Function keys
The user is alerted as though beep() were called.
Information concerning the function keys is not
returned to the caller.


If the current or specified window is not a pad, and it has been
moved modified since the last refresh operation, then it will be
refreshed before another character is read.

Constant Values for Function Keys

The following is a list of tokens for function keys that are returned
by the getch() set of functions if keypad handling is enabled (some
terminals may not support all tokens).


+-------------------------------------------------+
| Constant Description |
+-------------------------------------------------+
|KEY_BREAK Break key |
|KEY_DOWN The down arrow key |
|KEY_UP The up arrow key |
|KEY_LEFT The left arrow key |
|KEY_RIGHT The right arrow key |
|KEY_HOME Home key |
|KEY_BACKSPACE Backspace |
|KEY_F0 Function keys. Space for 64 |
| keys is reserved. |
|KEY_F(n) For 0 <= n <= 63 |
|KEY_DL Delete line |
|KEY_IL Insert line |
|KEY_DC Delete character |
|KEY_IC Insert char or enter insert mode |
|KEY_EIC Exit insert char mode |
|KEY_CLEAR Clear screen |
|KEY_EOS Clear to end of screen |
|KEY_EOL Clear to end of line |
|KEY_SF Scroll 1 line forward |
| KEY_SR Scroll 1 line backwards |
|KEY_NPAGE Next page |
|KEY_PPAGE Previous page |
|KEY_STAB Set tab |
|KEY_CTAB Clear tab |
|KEY_CATAB Clear all tabs |
|KEY_ENTER Enter or send |
|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_A1 Upper left of keypad |
|KEY_A3 Upper right of keypad |
|KEY_B2 Center of keypad |
|KEY_C1 Lower left of keypad |
|KEY_C3 Lower right of keypad |
|KEY_BTAB Back tab |
|KEY_BEG Beginning key |
|KEY_CANCEL Cancel key |
|KEY_CLOSE Close key |
|KEY_COMMAND Cmd (command) key |
|KEY_COPY Copy key |
|KEY_CREATE Create key |
|KEY_END End key |
|KEY_EXIT Exit key |
|KEY_FIND Find key |
|KEY_HELP Help key |
|KEY_MARK Mark key |
|KEY_MESSAGE Message key |
|KEY_MOVE Move key |
|KEY_NEXT Next object key |
|KEY_OPEN Open key |
|KEY_OPTIONS Options key |
|KEY_PREVIOUS Previous object key |
|KEY_REDO Redo key |
|KEY_REFERENCE Reference key |
|KEY_REFRESH Refresh key |
|KEY_REPLACE Replace key |
|KEY_RESTART Restart key |
|KEY_RESUME Resume key |
|KEY_SAVE Save key |
|KEY_SBEG Shifted beginning key |
|KEY_SCANCEL Shifted cancel key |
|KEY_SCOMMAND Shifted command key |
|KEY_SCOPY Shifted copy key |
|KEY_SCREATE Shifted create key |
|KEY_SDC Shifted delete char key |
|KEY_SDL Shifted delete line key |
|KEY_SELECT Select key |
|KEY_SEND Shifted end key |
|KEY_SEOL Shifted clear line key |
|KEY_SEXIT Shifted exit key |
|KEY_SFIND Shifted find key |
|KEY_SHELP Shifted help key |
|KEY_SHOME Shifted home key |
|KEY_SIC Shifted input key |
|KEY_SLEFT Shifted left arrow key |
|KEY_SMESSAGES Shifted messages key |
|KEY_SMOVE Shifted move key |
|KEY_SNEXT Shifted next key |
|KEY_SOPTIONS Shifted options key |
|KEY_SPREVIOUS Shifted previous key |
|KEY_SPRINT Shifted print key |
|KEY_SREDO Shifted redo key |
|KEY_SREPLACE Shifted replace key |
|KEY_SRIGHT Shifted right arrow key |
|KEY_SRSUME Shifted resume key |
|KEY_SSAVE Shifted save key |
|KEY_SSUSPEND Shifted suspend key |
|KEY_SUNDO Shifted undo key |
|KEY_SUSPEND Suspend key |
|KEY_UNDO Undo key |
+-------------------------------------------------+

RETURN VALUES

Upon successful completion, these functions return the single-byte
character, KEY_ value, or ERR. When in the nodelay mode and no data
is available, ERR is returned.

ERRORS

No errors are defined.

USAGE

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


When using these functions, nocbreak mode (cbreak(3XCURSES)) and echo
mode (echo(3XCURSES)) should not be used at the same time. Depending
on the state of the terminal when each character is typed, the
application may produce undesirable results.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | Unsafe |
+--------------------+-----------------+

SEE ALSO

cbreak(3XCURSES), echo(3XCURSES), halfdelay(3XCURSES),
keypad(3XCURSES), libcurses(3XCURSES), nodelay(3XCURSES),
notimeout(3XCURSES), raw(3XCURSES), timeout(3XCURSES), attributes(7),
standards(7)

June 5, 2002 GETCH(3XCURSES)