CURS_GETCH(3CURSES) Curses Library Functions CURS_GETCH(3CURSES)


NAME


curs_getch, getch, wgetch, mvgetch, mvwgetch, ungetch - get (or push
back) characters from curses terminal keyboard

SYNOPSIS


cc [ 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);


int ungetch(int ch);


DESCRIPTION


With the getch(), wgetch(), mvgetch(), and mvwgetch() routines a
character is read from the terminal associated with 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. Unless noecho() has been set, the
character will also be echoed into the designated window.


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> with integers beginning with 0401, whose
names begin with KEY_. If a character that could be the beginning of a
function key (such as escape) is received, 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. Since tokens returned by these routines are outside the ASCII
range, they are not printable.


The ungetch() routine places ch back onto the input queue to be returned
by the next call to wgetch().

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 may be
supported on a particular terminal if the terminal does not transmit a
unique code when the key is pressed or if the definition for the key is
not present in the terminfo database.


Name Key name
-------------------------------------------------
KEY_BREAK Break key
KEY_DOWN The four arrow keys ...
KEY_UP
KEY_LEFT
KEY_RIGHT
KEY_HOME Home key (upward+left arrow)
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 backward (reverse)
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). Keypad is arranged like
this: (Row 1) A1 up A3 (Row
2) left B2 right (Row 3) C1
down C3
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
KEY_BEG Beg(inning) 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_SMESSAGE Shifted message key
KEY_SMOVE Shifted move key
KEY_SNEXT Shifted next key
KEY_SOPTIONS Shifted options key
KEY_SPREVIOUS Shifted prev key
KEY_SPRINT Shifted print key
KEY_SREDO Shifted redo key
KEY_SREPLACE Shifted replace key
KEY_SRIGHT Shifted right arrow
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


All routines return the integer ERR upon failure. The ungetch() routine
returns an integer value other than ERR upon successful completion. The
other routines return the next input character or function key code upon
successful completion.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | Unsafe |
+---------------+-----------------+

SEE ALSO


curs_inopts(3CURSES), curs_move(3CURSES), curs_refresh(3CURSES),
curses(3CURSES), attributes(5)

NOTES


The header <curses.h> automatically includes the headers <stdio.h> and
<unctrl.h>.


Use of the escape key for a single character function is discouraged.


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.


December 31, 1996 CURS_GETCH(3CURSES)