curs_getch, getch, wgetch, mvgetch, mvwgetch, ungetch - get (or push back) characters from curses terminal keyboard
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);
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().
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.
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.
See attributes(7) for descriptions of the following attributes:
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.