curs_kernel 3x
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 typically 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 re-
set_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().
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 doupdate, 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 in-
clude these lines; therefore, y and x should be used only
as arguments 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 rou-
tines getsyx and setsyx are designed to be used by a li-
brary 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 be-
ginning, 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 facili-
ty 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 win-
dow that has been allocated and an integer with the number
of columns in the window. Inside this initialization rou-
tine, 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 in-
visible, 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 re-
turned; 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 implementa-
tion
def_prog_mode, def_shell_mode, reset_prog_mode, re-
set_shell_mode
return an error if the terminal was not ini-
tialized, 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 implementation
gets it right, but it may be unwise to count on the cor-
rectness 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 hav-
ing 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_re-
fresh(3x), curs_scr_dump(3x), curs_slk(3x)
curs_kernel(3x)
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