usr/src/lib/libcurses/tstp.c

# include       <signal.h>

# include       "curses.ext"

/*
 * handle stop and start signals
 *
 * @(#)tstp.c   1.4 (Berkeley) %G%
 */
tstp() {

# ifdef SIGTSTP

        SGTTY   tty;
        int     omask;
# ifdef DEBUG
        if (outf)
                fflush(outf);
# endif
        tty = _tty;
        mvcur(0, COLS - 1, LINES - 1, 0);
        endwin();
        fflush(stdout);
        /* reset signal handler so kill below stops us */
        signal(SIGTSTP, SIG_DFL);
#define mask(s) (1 << ((s)-1))
        omask = sigsetmask(sigblock(0) &~ mask(SIGTSTP));
        kill(0, SIGTSTP);
        sigblock(mask(SIGTSTP));
        signal(SIGTSTP, tstp);
        _tty = tty;
        stty(_tty_ch, &_tty);
        wrefresh(curscr);
# endif SIGTSTP
}