2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
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
39 static char sccsid[] = "@(#)trap.c 8.5 (Berkeley) 6/5/95";
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD: src/bin/sh/trap.c,v 1.20.2.2 2002/08/27 01:36:28 tjr Exp $");
51 #include "nodes.h" /* for other headers */
62 #include "myhistedit.h"
66 * Sigmode records the current value of the signal handlers for the various
67 * modes. A value of zero means that the current handler is not known.
68 * S_HARD_IGN indicates that the signal was ignored on entry to the shell,
71 #define S_DFL 1 /* default signal handling (SIG_DFL) */
72 #define S_CATCH 2 /* signal is caught */
73 #define S_IGN 3 /* signal is ignored (SIG_IGN) */
74 #define S_HARD_IGN 4 /* signal is ignored permanently */
75 #define S_RESET 5 /* temporary - to reset a hard ignored sig */
78 MKINIT char sigmode[NSIG]; /* current value of signal */
79 int pendingsigs; /* indicates some signal received */
80 int in_dotrap; /* do we execute in a trap handler? */
81 static char *volatile trap[NSIG]; /* trap handler commands */
82 static volatile sig_atomic_t gotsig[NSIG];
83 /* indicates specified signal received */
84 static int ignore_sigchld; /* Used while handling SIGCHLD traps. */
85 volatile sig_atomic_t gotwinch;
87 static int getsigaction(int, sig_t *);
91 * Map a string to a signal number.
94 sigstring_to_signum(char *sig)
101 return ((signo >= 0 && signo < NSIG) ? signo : (-1));
102 } else if (strcasecmp(sig, "exit") == 0) {
107 if (strncasecmp(sig, "sig", 3) == 0)
109 for (n = 1; n < NSIG; n++)
110 if (strcasecmp(sys_signame[n], sig) == 0)
118 * Print a list of valid signal names.
125 for (n = 1; n < NSIG; n++) {
126 out1fmt("%s", sys_signame[n]);
127 if (n == (NSIG / 2) || n == (NSIG - 1))
139 trapcmd(int argc, char **argv)
145 for (signo = 0 ; signo < NSIG ; signo++) {
146 if (trap[signo] != NULL)
147 out1fmt("trap -- '%s' %s\n", trap[signo],
148 (signo) ? sys_signame[signo] : "exit");
153 if (*++argv && strcmp(*argv, "--") == 0)
155 if (*argv && sigstring_to_signum(*argv) == -1) {
156 if ((*argv)[0] != '-') {
159 } else if ((*argv)[1] == '\0') {
161 } else if ((*argv)[1] == 'l' && (*argv)[2] == '\0') {
165 error("bad option %s", *argv);
169 if ((signo = sigstring_to_signum(*argv)) == -1)
170 error("bad signal %s", *argv);
173 action = savestr(action);
176 trap[signo] = action;
187 * Clear traps on a fork.
194 for (tp = trap ; tp <= &trap[NSIG - 1] ; tp++) {
195 if (*tp && **tp) { /* trap not NULL or SIG_IGN */
200 setsignal(tp - trap);
208 * Set the signal handler for the specified signal. The routine figures
209 * out what it should be set to.
215 sig_t sig, sigact = SIG_DFL;
218 if ((t = trap[signo]) == NULL)
224 if (action == S_DFL) {
241 if (rootshell && iflag)
247 if (rootshell && mflag)
253 if (rootshell && iflag)
263 * current setting unknown
265 if (!getsigaction(signo, &sigact)) {
267 * Pretend it worked; maybe we should give a warning
268 * here, but other shells don't. We don't alter
269 * sigmode, so that we retry every time.
273 if (sigact == SIG_IGN) {
274 if (mflag && (signo == SIGTSTP ||
275 signo == SIGTTIN || signo == SIGTTOU)) {
276 *t = S_IGN; /* don't hard ignore these */
280 *t = S_RESET; /* force to be set */
283 if (*t == S_HARD_IGN || *t == action)
286 case S_DFL: sigact = SIG_DFL; break;
287 case S_CATCH: sigact = onsig; break;
288 case S_IGN: sigact = SIG_IGN; break;
291 sig = signal(signo, sigact);
292 if (sig != SIG_ERR && action == S_CATCH)
293 siginterrupt(signo, 1);
298 * Return the current setting for sig w/o changing it.
301 getsigaction(int signo, sig_t *sigact)
305 if (sigaction(signo, (struct sigaction *)0, &sa) == -1)
307 *sigact = (sig_t) sa.sa_handler;
319 if (sigmode[signo] != S_IGN && sigmode[signo] != S_HARD_IGN) {
320 signal(signo, SIG_IGN);
322 sigmode[signo] = S_HARD_IGN;
334 for (sm = sigmode ; sm < sigmode + NSIG ; sm++) {
349 if (signo == SIGINT && trap[SIGINT] == NULL) {
354 if (signo != SIGCHLD || !ignore_sigchld)
358 /* If we are currently in a wait builtin, prepare to break it */
359 if ((signo == SIGINT || signo == SIGQUIT) && in_waitcmd != 0)
362 * If a trap is set, not ignored and not the null command, we need
363 * to make sure traps are executed even when a child blocks signals.
366 trap[signo] != NULL &&
367 ! trap[signo][0] == '\0' &&
368 ! (trap[signo][0] == ':' && trap[signo][1] == '\0'))
372 if (signo == SIGWINCH)
379 * Called to execute a trap. Perhaps we should avoid entering new trap
380 * handlers while we are executing a trap handler.
390 for (i = 1; i < NSIG; i++) {
395 * Ignore SIGCHLD to avoid infinite recursion
396 * if the trap action does a fork.
400 savestatus = exitstatus;
402 exitstatus = savestatus;
418 * Controls whether the shell is interactive or not.
421 setinteractive(int on)
423 static int is_interactive = -1;
425 if (on == is_interactive)
438 * Called to exit the shell.
441 exitshell(int status)
443 struct jmploc loc1, loc2;
446 TRACE(("exitshell(%d) pid=%d\n", status, getpid()));
447 if (setjmp(loc1.loc)) {
450 if (setjmp(loc2.loc)) {
454 if ((p = trap[0]) != NULL && *p != '\0') {
458 l1: handler = &loc2; /* probably unnecessary */