1 /* 2 * Copyright (c) 1981, 1993, 1994 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 static char sccsid[] = "@(#)tstp.c 8.3 (Berkeley) 5/4/94"; 36 #endif /* not lint */ 37 38 #include <errno.h> 39 #include <signal.h> 40 #include <termios.h> 41 #include <unistd.h> 42 43 #include "curses.h" 44 45 /* 46 * stop_signal_handler -- 47 * Handle stop signals. 48 */ 49 void 50 __stop_signal_handler(signo) 51 int signo; 52 { 53 struct termios save; 54 sigset_t oset, set; 55 56 /* Get the current terminal state (which the user may have changed). */ 57 if (tcgetattr(STDIN_FILENO, &save)) 58 return; 59 60 /* 61 * Block window change and timer signals. The latter is because 62 * applications use timers to decide when to repaint the screen. 63 */ 64 (void)sigemptyset(&set); 65 (void)sigaddset(&set, SIGALRM); 66 (void)sigaddset(&set, SIGWINCH); 67 (void)sigprocmask(SIG_BLOCK, &set, &oset); 68 69 /* 70 * End the window, which also resets the terminal state to the 71 * original modes. 72 */ 73 endwin(); 74 75 /* Unblock SIGTSTP. */ 76 (void)sigemptyset(&set); 77 (void)sigaddset(&set, SIGTSTP); 78 (void)sigprocmask(SIG_UNBLOCK, &set, NULL); 79 80 /* Stop ourselves. */ 81 __restore_stophandler(); 82 (void)kill(0, SIGTSTP); 83 84 /* Time passes ... */ 85 86 /* Reset the curses SIGTSTP signal handler. */ 87 __set_stophandler(); 88 89 /* save the new "default" terminal state */ 90 (void)tcgetattr(STDIN_FILENO, &__orig_termios); 91 92 /* Reset the terminal state to the mode just before we stopped. */ 93 (void)tcsetattr(STDIN_FILENO, __tcaction ? 94 TCSASOFT | TCSADRAIN : TCSADRAIN, &save); 95 96 /* Restart the screen. */ 97 __startwin(); 98 99 /* Repaint the screen. */ 100 wrefresh(curscr); 101 102 /* Reset the signals. */ 103 (void)sigprocmask(SIG_SETMASK, &oset, NULL); 104 } 105 106 static void (*otstpfn)() = SIG_DFL; 107 108 /* 109 * Set the TSTP handler. 110 */ 111 void 112 __set_stophandler() 113 { 114 otstpfn = signal(SIGTSTP, __stop_signal_handler); 115 } 116 117 /* 118 * Restore the TSTP handler. 119 */ 120 void 121 __restore_stophandler() 122 { 123 (void)signal(SIGTSTP, otstpfn); 124 } 125