overlay, overwrite, copywin - overlay and manipulate overlapped curses
int overlay(const WINDOW *srcwin, WINDOW *dstwin);
int overwrite(const WINDOW *srcwin, WINDOW *dstwin);
int copywin(const WINDOW *srcwin, WINDOW *dstwin, int sminrow,
int smincol, int dminrow, int dmincol, int dmaxrow,
int dmaxcol, int overlay);
The overlay and overwrite routines overlay srcwin on top of dstwin.
scrwin and dstwin are not required to be the same size; only text where
the two windows overlap is copied. The difference is that overlay is
non-destructive (blanks are not copied) whereas overwrite is destruc‐
The copywin routine provides a finer granularity of control over the
overlay and overwrite routines. Like in the prefresh routine, a rec‐
tangle is specified in the destination window, (dminrow, dmincol) and
(dmaxrow, dmaxcol), and the upper-left-corner coordinates of the source
window, (sminrow, smincol). If the argument overlay is true, then
copying is non-destructive, as in overlay.
Routines that return an integer return ERR upon failure, and OK (SVr4
only specifies "an integer value other than ERR") upon successful com‐
X/Open defines no error conditions. In this implementation, copywin,
overlay and overwrite return an error if either of the window pointers
are null, or if some part of the window would be placed off-screen.
Note that overlay and overwrite may be macros.
The XSI Curses standard, Issue 4 describes these functions (adding the
const qualifiers). It further specifies their behavior in the presence
of characters with multibyte renditions (not yet supported in this im‐
SEE ALSOcurses(3X), curs_pad(3X), curs_refresh(3X)curs_overlay(3X)