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