int scr_dump(const char *filename);
int scr_restore(const char *filename);
int scr_init(const char *filename);
int scr_set(const char *filename);
The scr_restore routine sets the virtual screen to the contents of filename, which must have been written using scr_dump. The next call to doupdate restores the screen to the way it looked in the dump file.
The scr_init routine reads in the contents of filename and uses them to initialize the curses data structures about what the terminal currently has on its screen. If the data is determined to be valid, curses bases its next update of the screen on this information rather than clearing the screen and starting from scratch. scr_init is used after initscr or a system call to share the screen with another process which has done a scr_dump after its endwin call. The data is declared invalid if the terminfo capabilities rmcup and nrrmc exist; also if the terminal has been written to since the preceding scr_dump call.
The scr_set routine is a combination of scr_restore and scr_init. It tells the program that the information in filename is what is currently on the screen, and also what the program wants on the screen. This can be thought of as a screen inheritance function.
To read (write) a window from (to) a file, use the getwin and putwin routines [see curs_util(3X)].
X/Open defines no error conditions. In this implementation, each will return an error if the file cannot be opened.
The SVr4 docs merely say under scr_init that the dump data is also considered invalid "if the time-stamp of the tty is old" but do not define "old".