|
HTML rendering created 2026-01-16 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. |
|
|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | PORTABILITY | HISTORY | SEE ALSO | COLOPHON |
|
|
|
curs_touch(3X) Library calls curs_touch(3X)
touchwin, touchline, untouchwin, wtouchln, is_linetouched,
is_wintouched - control terminal output refresh in a curses window
#include <curses.h>
int touchline(WINDOW *win, int start, int count);
int touchwin(WINDOW *win);
int wtouchln(WINDOW *win, int y, int n, int changed);
int untouchwin(WINDOW *win);
bool is_linetouched(WINDOW *win, int line);
bool is_wintouched(WINDOW *win);
The touchwin and touchline routines throw away all optimization
information about which parts of the window have been touched, by
pretending that the entire window has been drawn on. This is
sometimes necessary when using overlapping windows, since a change
to one window affects the other window, but the records of which
lines have been changed in the other window do not reflect the
change. The routine touchline only pretends that count lines have
been changed, beginning with line start.
The untouchwin routine marks all lines in the window as unchanged
since the last call to wrefresh.
The wtouchln routine makes n lines in the window, starting at line
y, look as if they have (changed=1) or have not (changed=0) been
changed since the last call to wrefresh.
The is_linetouched and is_wintouched routines return TRUE if the
specified line/window was modified since the last call to
wrefresh; otherwise they return FALSE. In addition,
is_linetouched returns ERR if line is not valid for the given
window.
Functions returning integers return ERR upon failure and OK upon
success.
In ncurses,
is_linetouched
returns ERR if the window pointer is null, or if the line
number is outside the window boundaries.
The constant ERR is distinct from TRUE and FALSE, which
are the normal return values of this function. Because
the function returns a bool, returning ERR (which is
neither TRUE nor FALSE) may not be supported by the
compiler.
To provide error-checking and also match the X/Open
function prototype, the ERR is provided by a macro named
is_linetouched. The actual function returns FALSE when it
detects an error.
wtouchln
returns ERR if the window pointer is null, or if the line
number is outside the window boundaries.
All of these functions except wtouchln may be implemented as
macros.
X/Open Curses Issue 4 describes these functions. It specifies no
error conditions for them.
SVr4 describes a successful return value except where “otherwise
noted” as “an integer value other than ERR”.
SVr4 does not check win to ensure that it is not a null pointer.
SVr2 (1984) introduced touchwin,
SVr3 (1987) added touchline. SVr3.1 later that year supplied
is_linetouched, is_wintouched, untouchwin, and wtouchln.
curses(3X), curs_refresh(3X), curs_variables(3X)
This page is part of the ncurses (new curses) project.
Information about the project can be found at
⟨https://invisible-island.net/ncurses/ncurses.html⟩. If you have a
bug report for this manual page, send it to bug-ncurses@gnu.org.
This page was obtained from the tarball ncurses-6.6.tar.gz fetched
from ⟨https://ftp.gnu.org/gnu/ncurses/⟩ on 2026-01-16. 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 man-pages@man7.org
ncurses @NCURSES_MAJOR@.@NCU... 2025-01-18 curs_touch(3X)
|
HTML rendering created 2026-01-16 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. |
|