signal.c revision 1.2
1 /* $NetBSD: signal.c,v 1.2 1998/01/09 08:03:37 perry Exp $ */ 2 3 /* 4 * Copyright (c) 1988 Mark Nudleman 5 * Copyright (c) 1988, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static char sccsid[] = "@(#)signal.c 8.1 (Berkeley) 6/6/93"; 39 #endif /* not lint */ 40 41 /* 42 * Routines dealing with signals. 43 * 44 * A signal usually merely causes a bit to be set in the "signals" word. 45 * At some convenient time, the mainline code checks to see if any 46 * signals need processing by calling psignal(). 47 * If we happen to be reading from a file [in iread()] at the time 48 * the signal is received, we call intread to interrupt the iread. 49 */ 50 51 #include <less.h> 52 #include <signal.h> 53 54 /* 55 * "sigs" contains bits indicating signals which need to be processed. 56 */ 57 int sigs; 58 59 #ifdef SIGTSTP 60 #define S_STOP 02 61 #endif 62 #if defined(SIGWINCH) || defined(SIGWIND) 63 #define S_WINCH 04 64 #endif 65 66 extern int sc_width, sc_height; 67 extern int screen_trashed; 68 extern int lnloop; 69 extern int linenums; 70 extern int scroll; 71 extern int reading; 72 73 #ifdef SIGTSTP 74 /* 75 * "Stop" (^Z) signal handler. 76 */ 77 static void 78 stop() 79 { 80 (void)signal(SIGTSTP, stop); 81 sigs |= S_STOP; 82 if (reading) 83 intread(); 84 } 85 #endif 86 87 #ifdef SIGWINCH 88 /* 89 * "Window" change handler 90 */ 91 void 92 winch() 93 { 94 (void)signal(SIGWINCH, winch); 95 sigs |= S_WINCH; 96 if (reading) 97 intread(); 98 } 99 #else 100 #ifdef SIGWIND 101 /* 102 * "Window" change handler 103 */ 104 winch() 105 { 106 (void)signal(SIGWIND, winch); 107 sigs |= S_WINCH; 108 if (reading) 109 intread(); 110 } 111 #endif 112 #endif 113 114 static void 115 purgeandquit() 116 { 117 118 purge(); /* purge buffered output */ 119 quit(); 120 } 121 122 /* 123 * Set up the signal handlers. 124 */ 125 init_signals(on) 126 int on; 127 { 128 if (on) 129 { 130 /* 131 * Set signal handlers. 132 */ 133 (void)signal(SIGINT, purgeandquit); 134 #ifdef SIGTSTP 135 (void)signal(SIGTSTP, stop); 136 #endif 137 #ifdef SIGWINCH 138 (void)signal(SIGWINCH, winch); 139 #else 140 #ifdef SIGWIND 141 (void)signal(SIGWIND, winch); 142 #endif 143 #endif 144 } else 145 { 146 /* 147 * Restore signals to defaults. 148 */ 149 (void)signal(SIGINT, SIG_DFL); 150 #ifdef SIGTSTP 151 (void)signal(SIGTSTP, SIG_DFL); 152 #endif 153 #ifdef SIGWINCH 154 (void)signal(SIGWINCH, SIG_IGN); 155 #endif 156 #ifdef SIGWIND 157 (void)signal(SIGWIND, SIG_IGN); 158 #endif 159 } 160 } 161 162 /* 163 * Process any signals we have received. 164 * A received signal cause a bit to be set in "sigs". 165 */ 166 psignals() 167 { 168 register int tsignals; 169 170 if ((tsignals = sigs) == 0) 171 return; 172 sigs = 0; 173 174 #ifdef S_WINCH 175 if (tsignals & S_WINCH) 176 { 177 int old_width, old_height; 178 /* 179 * Re-execute get_term() to read the new window size. 180 */ 181 old_width = sc_width; 182 old_height = sc_height; 183 get_term(); 184 if (sc_width != old_width || sc_height != old_height) 185 { 186 scroll = (sc_height + 1) / 2; 187 screen_trashed = 1; 188 } 189 } 190 #endif 191 #ifdef SIGTSTP 192 if (tsignals & S_STOP) 193 { 194 /* 195 * Clean up the terminal. 196 */ 197 #ifdef SIGTTOU 198 (void)signal(SIGTTOU, SIG_IGN); 199 #endif 200 lower_left(); 201 clear_eol(); 202 deinit(); 203 (void)flush(); 204 raw_mode(0); 205 #ifdef SIGTTOU 206 (void)signal(SIGTTOU, SIG_DFL); 207 #endif 208 (void)signal(SIGTSTP, SIG_DFL); 209 (void)kill(getpid(), SIGTSTP); 210 /* 211 * ... Bye bye. ... 212 * Hopefully we'll be back later and resume here... 213 * Reset the terminal and arrange to repaint the 214 * screen when we get back to the main command loop. 215 */ 216 (void)signal(SIGTSTP, stop); 217 raw_mode(1); 218 init(); 219 screen_trashed = 1; 220 } 221 #endif 222 } 223
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