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curs_kernel


Section: Miscellaneous Library Functions (3X)
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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 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 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 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

curses(3X), curs_initscr(3X), curs_outopts(3X), curs_refresh(3X),
curs_scr_dump(3X), curs_slk(3X)



 

Index



NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

NOTES

PORTABILITY

SEE ALSO



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