signal.c revision 1.4
1 /* $NetBSD: signal.c,v 1.4 2003/08/07 09:28:01 agc Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 1988 Mark Nudleman 34 * 35 * Redistribution and use in source and binary forms, with or without 36 * modification, are permitted provided that the following conditions 37 * are met: 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 2. Redistributions in binary form must reproduce the above copyright 41 * notice, this list of conditions and the following disclaimer in the 42 * documentation and/or other materials provided with the distribution. 43 * 3. All advertising materials mentioning features or use of this software 44 * must display the following acknowledgement: 45 * This product includes software developed by the University of 46 * California, Berkeley and its contributors. 47 * 4. Neither the name of the University nor the names of its contributors 48 * may be used to endorse or promote products derived from this software 49 * without specific prior written permission. 50 * 51 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 52 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 53 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 54 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 55 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 56 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 57 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 59 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 60 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 61 * SUCH DAMAGE. 62 */ 63 64 #include <sys/cdefs.h> 65 #ifndef lint 66 #if 0 67 static char sccsid[] = "@(#)signal.c 8.1 (Berkeley) 6/6/93"; 68 #else 69 __RCSID("$NetBSD: signal.c,v 1.4 2003/08/07 09:28:01 agc Exp $"); 70 #endif 71 #endif /* not lint */ 72 73 /* 74 * Routines dealing with signals. 75 * 76 * A signal usually merely causes a bit to be set in the "signals" word. 77 * At some convenient time, the mainline code checks to see if any 78 * signals need processing by calling psignal(). 79 * If we happen to be reading from a file [in iread()] at the time 80 * the signal is received, we call intread to interrupt the iread. 81 */ 82 83 #include <signal.h> 84 #include <unistd.h> 85 86 #include "less.h" 87 #include "extern.h" 88 89 /* 90 * "sigs" contains bits indicating signals which need to be processed. 91 */ 92 int sigs; 93 94 #ifdef SIGTSTP 95 #define S_STOP 02 96 #endif 97 #if defined(SIGWINCH) || defined(SIGWIND) 98 #define S_WINCH 04 99 #endif 100 101 102 static void purgeandquit __P((int)); 103 104 #ifdef SIGTSTP 105 static void stop __P((int)); 106 /* 107 * "Stop" (^Z) signal handler. 108 */ 109 static void 110 stop(n) 111 int n; 112 { 113 (void)signal(SIGTSTP, stop); 114 sigs |= S_STOP; 115 if (reading) 116 intread(); 117 } 118 #endif 119 120 #ifdef SIGWINCH 121 /* 122 * "Window" change handler 123 */ 124 void 125 winch(n) 126 int n; 127 { 128 (void)signal(SIGWINCH, winch); 129 sigs |= S_WINCH; 130 if (reading) 131 intread(); 132 } 133 #else 134 #ifdef SIGWIND 135 /* 136 * "Window" change handler 137 */ 138 winch() 139 { 140 (void)signal(SIGWIND, winch); 141 sigs |= S_WINCH; 142 if (reading) 143 intread(); 144 } 145 #endif 146 #endif 147 148 static void 149 purgeandquit(n) 150 int n; 151 { 152 153 purge(); /* purge buffered output */ 154 quit(); 155 } 156 157 /* 158 * Set up the signal handlers. 159 */ 160 void 161 init_signals(on) 162 int on; 163 { 164 if (on) 165 { 166 /* 167 * Set signal handlers. 168 */ 169 (void)signal(SIGINT, purgeandquit); 170 #ifdef SIGTSTP 171 (void)signal(SIGTSTP, stop); 172 #endif 173 #ifdef SIGWINCH 174 (void)signal(SIGWINCH, winch); 175 #else 176 #ifdef SIGWIND 177 (void)signal(SIGWIND, winch); 178 #endif 179 #endif 180 } else 181 { 182 /* 183 * Restore signals to defaults. 184 */ 185 (void)signal(SIGINT, SIG_DFL); 186 #ifdef SIGTSTP 187 (void)signal(SIGTSTP, SIG_DFL); 188 #endif 189 #ifdef SIGWINCH 190 (void)signal(SIGWINCH, SIG_IGN); 191 #endif 192 #ifdef SIGWIND 193 (void)signal(SIGWIND, SIG_IGN); 194 #endif 195 } 196 } 197 198 /* 199 * Process any signals we have received. 200 * A received signal cause a bit to be set in "sigs". 201 */ 202 void 203 psignals() 204 { 205 int tsignals; 206 207 if ((tsignals = sigs) == 0) 208 return; 209 sigs = 0; 210 211 #ifdef S_WINCH 212 if (tsignals & S_WINCH) 213 { 214 int old_width, old_height; 215 /* 216 * Re-execute get_term() to read the new window size. 217 */ 218 old_width = sc_width; 219 old_height = sc_height; 220 get_term(); 221 if (sc_width != old_width || sc_height != old_height) 222 { 223 scroll = (sc_height + 1) / 2; 224 screen_trashed = 1; 225 } 226 } 227 #endif 228 #ifdef SIGTSTP 229 if (tsignals & S_STOP) 230 { 231 /* 232 * Clean up the terminal. 233 */ 234 #ifdef SIGTTOU 235 (void)signal(SIGTTOU, SIG_IGN); 236 #endif 237 lower_left(); 238 clear_eol(); 239 deinit(); 240 (void)flush(); 241 raw_mode(0); 242 #ifdef SIGTTOU 243 (void)signal(SIGTTOU, SIG_DFL); 244 #endif 245 (void)signal(SIGTSTP, SIG_DFL); 246 (void)kill(getpid(), SIGTSTP); 247 /* 248 * ... Bye bye. ... 249 * Hopefully we'll be back later and resume here... 250 * Reset the terminal and arrange to repaint the 251 * screen when we get back to the main command loop. 252 */ 253 (void)signal(SIGTSTP, stop); 254 raw_mode(1); 255 init(); 256 screen_trashed = 1; 257 } 258 #endif 259 } 260
Indexes created Sat Sep 27 22:09:54 GMT 2025