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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | PORTABILITY | SEE ALSO | COLOPHON |
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curs_kernel(3X) curs_kernel(3X)
def_prog_mode, def_shell_mode, reset_prog_mode, reset_shell_mode,
resetty, savetty, getsyx, setsyx, ripoffline, curs_set, napms -
low-level curses routines
#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);
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(3X) 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; there‐
fore, 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 cur‐
rent position of the program's cursor. The library routine would
call getsyx at the beginning, do its manipulation of its own win‐
dows, 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 curs_slk(3X)] 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 std‐
scr.
• 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 allo‐
cated 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 accu‐
rate and wrefresh or doupdate must not be called. It is allow‐
able 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.
Except for curs_set, these routines always return OK.
curs_set returns the previous cursor state, or ERR if the re‐
quested 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).
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., ei‐
ther invisible or very visible. There is no way for ncurses to
determine the initial cursor state to restore that.
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 re‐
turn type int. This is misleading, as they are macros with no
documented semantics for the return value.
curses(3X), curs_initscr(3X), curs_outopts(3X), curs_refresh(3X),
curs_scr_dump(3X), curs_slk(3X), curs_variables(3X).
This page is part of the ncurses (new curses) project. Informa‐
tion about the project can be found at
⟨https://www.gnu.org/software/ncurses/ncurses.html⟩. If you have
a bug report for this manual page, send it to
[email protected]. This page was obtained from the
project's upstream Git mirror of the CVS repository
⟨https://github.com/mirror/ncurses.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2023-03-12.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
curs_kernel(3X)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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