curs_kernel(3X) curs_kernel(3X)
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. Theses routines typi-cally typically
cally are used inside library routines.
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 rou-tines. routines.
tines. This is done automatically by initscr. There is one such save area for each screen context
allocated by newterm().
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 and, after an endwin, by doup-date, doupdate,
date, so they normally are not called.
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.
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 ar-guments arguments
guments for 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 manipu-lates manipulates
lates 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.
The ripoffline routine provides access to the same facility that slk_init [see curs_slk(3X)] uses to
reduce the size of the screen. ripoffline must be called before initscr or newterm is called. 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 this 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.
The curs_set routine sets the cursor state is set to invisible, normal, or very visible for visibili-ty visibility
ty equal to 0, 1, or 2 respectively. If the terminal supports the visibility requested, the previous
cursor state is returned; otherwise, ERR is returned.
The napms routine is used to sleep for ms milliseconds.
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 (NRIPS =
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 implemen-tation implementation
tation 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 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.
SEE ALSO
curses(3X), curs_initscr(3X), curs_outopts(3X), curs_refresh(3X), curs_scr_dump(3X), curs_slk(3X)
curs_kernel(3X)
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