HP-UX Reference (11i v2 03/08) - 3 Library Functions A-M (vol 6)

derwin(3X) derwin(3X)

(CURSES)

NAME

derwin - relative window creation function

SYNOPSIS

#include <curses.h>

WINDOW *derwin(WINDOW *orig, int nlines, int ncols, int begin_y,

int begin_x);

DESCRIPTION

The derwin() function creates a new window with nlines lines and ncols columns, positioned so that

the origin is at (begin_y, begin_x) relative to the origin of the window orig. If any part of the new window

is outside orig, the function fails and the window is not created.

RETURN VALUE

Upon successful completion, these functions return a pointer to the new window. Otherwise, they return

a null pointer.

ERRORS

No errors are deﬁned.

APPLICATION USAGE

Before performing the ﬁrst refresh of a subwindow, portable applications should call

touchwin() or

touchline() on the parent window.

Each window maintains internal descriptions of the screen image and status. The screen image is shared

among all windows in the window hierarchy. Refresh operations rely on information on what has

changed within a window, which is private to each window. Refreshing a window, when updates were

made to a different window, may fail to perform needed updates because the windows do not share this

information.