curs_getch(3X)                                                  curs_getch(3X)

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

       #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);
       int has_key(int ch);

       The getch, wgetch, mvgetch and mvwgetch, routines read a character from
       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 charac-
       ter is typed or the specified timeout has been reached.

       Unless noecho has been set, then the character will also be echoed into
       the  designated window according to the following rules: If the charac-
       ter is the current erase character, left arrow, or backspace, the  cur-
       sor  is  moved one space to the left and that screen position is erased
       as if delch had been called.  If the character value is any other  KEY_
       define,  the user is alerted with a beep call.  Otherwise the character
       is simply output to the screen.

       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 func-
       tion keys are defined in <curses.h> as macros with values  outside  the
       range of 8-bit characters whose names begin with KEY_. Thus, a variable
       intended to hold the return value of a function key must  be  of  short
       size or larger.

       When  a  character  that  could  be  the beginning of a function key is
       received (which, on  modern  terminals,  means  an  escape  character),
       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.

       The  ungetch routine places ch back onto the input queue to be returned
       by the next call to wgetch.  There is just one input queue for all win-

   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  are
       necessarily supported on any particular terminal.

                  Name            Key name

                  KEY_BREAK       Break key
                  KEY_DOWN        The four arrow keys ...
                  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).
                  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_MOUSE       Mouse event read
                  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   Ref(erence) key
                  KEY_REFRESH     Refresh key
                  KEY_REPLACE     Replace key
                  KEY_RESIZE      Screen resized
                  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

       Keypad is arranged like this:

                                | A1  |  up  |  A3   |
                                |left |  B2  | right |
                                | C1  | down |  C3   |
       The has_key routine takes a key value from the above list, and  returns
       TRUE or FALSE according to whether the current terminal type recognizes
       a key with that value.

       All routines return the integer ERR upon failure and an  integer  value
       other  than  ERR  (OK in the case of ungetch()) upon successful comple-

       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.

       Note that some keys may be the same  as  commonly  used  control  keys,
       e.g., KEY_ENTER versus control/M, KEY_BACKSPACE 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.  Ncurses uses the terminfo definition.  If  it  says  that
       KEY_ENTER  is  control/M,  getch,  will return KEY_ENTER when you press

       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.

       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 consoles typically  support  little  more  than
       KEY_PPAGE, and function keys 1 through 12.   The  Ins  key  is  usually
       mapped to KEY_IC.

       The  *get* functions are described in the XSI Curses standard, Issue 4.
       They read single-byte characters only.   The  standard  specifies  that
       they return ERR on failure, but specifies no error conditions.

       The  echo  behavior  of  these  functions on input of KEY_ or backspace
       characters was not specified in the SVr4 documentation.  This  descrip-
       tion is adopted from the XSI Curses standard.

       The behavior of getch and friends in the presence of handled signals is
       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  read(2)
       call  in  progress or not, and also (in some implementations) depending
       on whether an input timeout or non-blocking mode hsd been set.

       Programmers concerned about portability should be prepared  for  either
       of  two  cases: (a) signal receipt does not interrupt getch; (b) signal
       receipt interrupts getch and causes it to return ERR with errno set  to
       EINTR.   Under the ncurses implementation, handled signals never inter-
       rupt getch.

       The has_key function is unique to ncurses.  We recommend that any  code
       using it be conditionalized on the NCURSES_VERSION feature macro.

       curses(3X),     curs_inopts(3X),     curs_mouse(3X),     curs_move(3X),
       curs_refresh(3X).  resizeterm(3X).