curs_get_wch, get_wch, wget_wch, mvget_wch, mvwget_wch, unget_wch - Get (or push back) a wide character from Curses terminal keyboard
const wchar_t wch
Curses Library (libcurses)
Interfaces documented on this reference page conform to industry standards as follows:
get_wch, wget_wch, mvget_wch, mvwget_wch, unget_wch: XPG4-UNIX
Refer to the
reference page for more information
about industry standards and associated tags.
The get_wch, wget_wch, mvget_wch, and mvwget_wch functions read a character from the terminal associated with the current or specified window. In no-delay mode, if no input is waiting, these functions return ERR. In delay mode, the program waits until the system passes text through to the program. Depending on the setting of cbreak, the program waits until it receives one character (in cbreak mode) or the first newline (in nocbreak mode). In half-delay mode, the program waits until the user types a character or the specified timeout interval has elapsed. Unless noecho has been set, these routines echo the character into the designated window.
If the window is not a pad and has been moved or modified since the last call to wrefresh, wrefresh is called before another character is read.
If keypad is enabled, these functions respond to the pressing of a function key by setting the object pointed to by wch to the corresponding KEY_ value defined in <curses.h> and returning KEY_CODE_YES. If a character (such as escape) that could be the beginning of a function key is received, Curses sets a timer. If the remainder of the sequence does arrive within the designated time, Curses passes through the character; otherwise, Curses returns the function key value. For this reason, many terminals experience a delay between the time a user presses the escape key and the time the escape is returned to the program.
function pushes the wide character
back onto the head of the input queue, so the wide character
is returned by the next call to
get_wch. The pushback of
one character is guaranteed. If the program calls
too many times without an intervening call to
the operation may fail.
The following function keys, defined in <curses.h>, may be returned by get_wch and related functions if keypad has been enabled. Note that a particular terminal may not support all of these function keys. In other words, the routines do not return a function key 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,
KEY_DOWN KEY_UP KEY_LEFT KEY_RIGHT
|The four arrow keys|
|KEY_HOME||Home key (upward+left arrow)|
|KEY_F0||Function keys; space for 64 keys is reserved.|
|KEY_F(n)||For 0 <= n <= 63|
|KEY_IC||Insert char or enter insert mode|
|KEY_EIC||Exit insert char mode|
|KEY_EOS||Clear to end-of-screen|
|KEY_EOL||Clear to end-of-line|
|KEY_SF||Scroll one line forward|
|KEY_SR||Scroll one line backward (in reverse)|
|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|
Home down or bottom (lower left). The
keypad is arranged like this:
A1 up A3 left B2 right 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_COMMAND||Cmd (command) key|
|KEY_NEXT||Next object key|
|KEY_PREVIOUS||Previous object 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 character key|
|KEY_SDL||Shifted delete line 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 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|
The header file <curses.h> automatically includes the header file <stdio.h>.
Applications should not define the escape key by itself as a single-character function.
When using get_wch, wget_wch, mvget_wch, or mvwget_wch, applications should not use nocbreak mode and echo mode at the same time. Depending on the state of the tty driver when each character is typed, the program may produce undesirable results.
may be macros.
When get_wch, wget_wch, mvget_wch, and mvwget_wch functions successfully report the pressing of a function key, they return KEY_CODE_YES. When they successfully report a wide character, they return OK. Otherwise, they return ERR.
Upon successful completion,
OK. Otherwise, the function returns
Functions: curses(3), curs_ins_wch(3), curs_inopts(3), curs_move(3), curs_refresh(3)