1 /* 2 * Copyright (c) 1981, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 /* from: static char sccsid[] = "@(#)tstp.c 8.2 (Berkeley) 11/2/93"; */ 36 static char *rcsid = "$Id: tstp.c,v 1.6 1993/11/09 04:08:55 cgd Exp $"; 37 #endif /* not lint */ 38 39 #include <curses.h> 40 #include <errno.h> 41 #include <signal.h> 42 #include <termios.h> 43 #include <unistd.h> 44 45 46 /* 47 * stop_signal_handler -- 48 * Handle stop signals. 49 */ 50 void 51 __stop_signal_handler(signo) 52 int signo; 53 { 54 struct termios save; 55 sigset_t oset, set; 56 57 /* Get the current terminal state (which the user may have changed). */ 58 if (tcgetattr(STDIN_FILENO, &save)) 59 return; 60 61 /* 62 * Block window change and timer signals. The latter is because 63 * applications use timers to decide when to repaint the screen. 64 */ 65 (void)sigemptyset(&set); 66 (void)sigaddset(&set, SIGALRM); 67 (void)sigaddset(&set, SIGWINCH); 68 (void)sigprocmask(SIG_BLOCK, &set, &oset); 69 70 /* 71 * End the window, which also resets the terminal state to the 72 * original modes. 73 */ 74 endwin(); 75 76 /* Unblock SIGTSTP. */ 77 (void)sigemptyset(&set); 78 (void)sigaddset(&set, SIGTSTP); 79 (void)sigprocmask(SIG_UNBLOCK, &set, NULL); 80 81 /* Stop ourselves. */ 82 __restore_stophandler(); 83 (void)kill(0, SIGTSTP); 84 85 /* Time passes ... */ 86 87 /* Reset the curses SIGTSTP signal handler. */ 88 __set_stophandler(); 89 90 /* save the new "default" terminal state */ 91 (void)tcgetattr(STDIN_FILENO, &__orig_termios); 92 93 /* Reset the terminal state to the mode just before we stopped. */ 94 (void)tcsetattr(STDIN_FILENO, __tcaction ? 95 TCSASOFT | TCSADRAIN : TCSADRAIN, &save); 96 97 /* Restart the screen. */ 98 __startwin(); 99 100 /* Repaint the screen. */ 101 wrefresh(curscr); 102 103 /* Reset the signals. */ 104 (void)sigprocmask(SIG_SETMASK, &oset, NULL); 105 } 106 107 static void (*otstpfn)() = SIG_DFL; 108 109 /* 110 * Set the TSTP handler. 111 */ 112 void 113 __set_stophandler() 114 { 115 otstpfn = signal(SIGTSTP, __stop_signal_handler); 116 } 117 118 /* 119 * Restore the TSTP handler. 120 */ 121 void 122 __restore_stophandler() 123 { 124 (void)signal(SIGTSTP, otstpfn); 125 } 126