Provided by: ncurses-doc_6.4+20240113-1ubuntu2_all bug

NAME

       def_prog_mode,   def_shell_mode,   reset_prog_mode,  reset_shell_mode,  resetty,  savetty,
       getsyx, setsyx, ripoffline, curs_set, napms - low-level curses routines

SYNOPSIS

       #include <curses.h>

       int def_prog_mode(void);
       int def_shell_mode(void);

       int reset_prog_mode(void);
       int reset_shell_mode(void);

       int resetty(void);
       int savetty(void);

       void getsyx(int y, int x);
       void setsyx(int y, int x);

       int ripoffline(int line, int (*init)(WINDOW *, int));
       int curs_set(int visibility);
       int napms(int ms);

DESCRIPTION

       The following routines give  low-level  access  to  various  curses  capabilities.   These
       routines typically are used inside library routines.

   def_prog_mode, def_shell_mode
       The  def_prog_mode  and  def_shell_mode  routines  save  the current terminal modes as the
       “program” (in curses) or “shell” (not in curses) state for use by the reset_prog_mode  and
       reset_shell_mode routines.  This is done automatically by initscr.  There is one such save
       area for each screen context allocated by newterm.

   reset_prog_mode, reset_shell_mode
       The reset_prog_mode and reset_shell_mode routines restore the terminal  to  “program”  (in
       curses)   or   “shell”   (out   of   curses)  state.   These  are  done  automatically  by
       endwin(3NCURSES) and, after an endwin, by doupdate, so they normally are not called.

   resetty, savetty
       The resetty and savetty routines save  and  restore  the  state  of  the  terminal  modes.
       savetty  saves the current state in a buffer and resetty restores the state to what it was
       at the last call to savetty.

   getsyx
       The getsyx routine returns the current coordinates of the virtual screen cursor in  y  and
       x.  If leaveok is currently TRUE, then -1,-1 is returned.  If lines have been removed from
       the top of the screen, using ripoffline, y and x include these lines; therefore, y  and  x
       should be used only as arguments for setsyx.

       Few applications will use this feature, most use getyx instead.

   setsyx
       The  setsyx  routine sets the virtual screen cursor to y, x.  If y and x are both -1, then
       leaveok is set.  The two routines getsyx and setsyx are designed to be used by  a  library
       routine, which manipulates curses windows but does not want to change the current position
       of the program's cursor.  The library routine would call getsyx at the beginning,  do  its
       manipulation  of  its own windows, do a wnoutrefresh on its windows, call setsyx, and then
       call doupdate.

       Few applications will use this feature, most use wmove instead.

   ripoffline
       The  ripoffline  routine  provides  access  to  the  same  facility  that  slk_init   [see
       slk(3NCURSES)]  uses  to  reduce the size of the screen.  ripoffline must be called before
       initscr or newterm is called, to prepare these initial actions:

       •   If line is positive, a line is removed from the top of stdscr.

       •   if line is negative, a line is removed from the bottom.

       When the resulting initialization is done inside initscr, the routine  init  (supplied  by
       the user) is called with two arguments:

       •   a window pointer to the one-line window that has been allocated and

       •   an integer with the number of columns in the window.

       Inside  this  initialization  routine,  the  integer  variables LINES and COLS (defined in
       <curses.h>) are not guaranteed to be accurate and wrefresh or doupdate must not be called.
       It is allowable to call wnoutrefresh during the initialization routine.

       ripoffline can be called up to five times before calling initscr or newterm.

   curs_set
       The  curs_set  routine  sets  the  cursor  state to invisible, normal, or very visible for
       visibility equal to 0, 1, or 2 respectively.  If  the  terminal  supports  the  visibility
       requested, the previous cursor state is returned; otherwise, ERR is returned.

   napms
       The napms routine is used to sleep for ms milliseconds.  If the value of ms exceeds 30,000
       (thirty seconds), it is capped at that value.

RETURN VALUE

       Except for curs_set, these routines always return OK.

       curs_set returns the previous cursor state, or ERR if  the  requested  visibility  is  not
       supported.

       X/Open defines no error conditions.  In this implementation

       def_prog_mode, def_shell_mode, reset_prog_mode, reset_shell_mode
            return an error if the terminal was not initialized, or if the I/O call to obtain the
            terminal settings fails.

       ripoffline
            returns an error if the maximum number of ripped-off lines exceeds the maximum (5).

NOTES

       Note that getsyx is a macro, so & is not necessary before the variables y and x.

       Older SVr4 man pages warn that the return value  of  curs_set  “is  currently  incorrect”.
       This implementation gets it right, but it may be unwise to count on the correctness of the
       return value anywhere else.

       Both ncurses and SVr4 will call curs_set in endwin if curs_set has been called to make the
       cursor  other  than  normal,  i.e., either invisible or very visible.  There is no way for
       ncurses to determine the initial cursor state to restore that.

PORTABILITY

       The virtual screen functions setsyx and  getsyx  are  not  described  in  the  XSI  Curses
       standard, Issue 4.  All other functions are as described in XSI Curses.

       The  SVr4  documentation  describes  setsyx and getsyx as having return type int.  This is
       misleading, as they are macros with no documented semantics for the return value.

       If interrupted, ncurses restarts napms.  That, and  the  limitation  to  30  seconds,  are
       different from other implementations.

SEE ALSO

       ncurses(3NCURSES),      initscr(3NCURSES),      outopts(3NCURSES),      refresh(3NCURSES),
       scr_dump(3NCURSES), slk(3NCURSES), curses_variables(3NCURSES)