freebsd-src/lib/libcurses/tstp.c
1994-05-27 05:00:24 +00:00

125 lines
3.6 KiB
C

/*
* Copyright (c) 1981, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)tstp.c 8.2 (Berkeley) 1/2/94";
#endif /* not lint */
#include <curses.h>
#include <errno.h>
#include <signal.h>
#include <termios.h>
#include <unistd.h>
/*
* stop_signal_handler --
* Handle stop signals.
*/
void
__stop_signal_handler(signo)
int signo;
{
struct termios save;
sigset_t oset, set;
/* Get the current terminal state (which the user may have changed). */
if (tcgetattr(STDIN_FILENO, &save))
return;
/*
* Block window change and timer signals. The latter is because
* applications use timers to decide when to repaint the screen.
*/
(void)sigemptyset(&set);
(void)sigaddset(&set, SIGALRM);
(void)sigaddset(&set, SIGWINCH);
(void)sigprocmask(SIG_BLOCK, &set, &oset);
/*
* End the window, which also resets the terminal state to the
* original modes.
*/
endwin();
/* Unblock SIGTSTP. */
(void)sigemptyset(&set);
(void)sigaddset(&set, SIGTSTP);
(void)sigprocmask(SIG_UNBLOCK, &set, NULL);
/* Stop ourselves. */
__restore_stophandler();
(void)kill(0, SIGTSTP);
/* Time passes ... */
/* Reset the curses SIGTSTP signal handler. */
__set_stophandler();
/* save the new "default" terminal state */
(void)tcgetattr(STDIN_FILENO, &__orig_termios);
/* Reset the terminal state to the mode just before we stopped. */
(void)tcsetattr(STDIN_FILENO, __tcaction ?
TCSASOFT | TCSADRAIN : TCSADRAIN, &save);
/* Restart the screen. */
__startwin();
/* Repaint the screen. */
wrefresh(curscr);
/* Reset the signals. */
(void)sigprocmask(SIG_SETMASK, &oset, NULL);
}
static void (*otstpfn)() = SIG_DFL;
/*
* Set the TSTP handler.
*/
void
__set_stophandler()
{
otstpfn = signal(SIGTSTP, __stop_signal_handler);
}
/*
* Restore the TSTP handler.
*/
void
__restore_stophandler()
{
(void)signal(SIGTSTP, otstpfn);
}