From 05c1076ba2d1a68fe7f3a5ae618f786b8898d327 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 26 Sep 2005 18:32:28 +1000 Subject: Initial import. --- src/trap.c | 395 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 395 insertions(+) create mode 100644 src/trap.c (limited to 'src/trap.c') diff --git a/src/trap.c b/src/trap.c new file mode 100644 index 0000000..7bc479b --- /dev/null +++ b/src/trap.c @@ -0,0 +1,395 @@ +/* $NetBSD: trap.c,v 1.28 2002/11/24 22:35:43 christos Exp $ */ + +/*- + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Kenneth Almquist. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include +#ifndef lint +#if 0 +static char sccsid[] = "@(#)trap.c 8.5 (Berkeley) 6/5/95"; +#else +__RCSID("$NetBSD: trap.c,v 1.28 2002/11/24 22:35:43 christos Exp $"); +#endif +#endif /* not lint */ + +#include +#include +#include +#include + +#include "shell.h" +#include "main.h" +#include "nodes.h" /* for other headers */ +#include "eval.h" +#include "jobs.h" +#include "show.h" +#include "options.h" +#include "syntax.h" +#include "output.h" +#include "memalloc.h" +#include "error.h" +#include "trap.h" +#include "mystring.h" + +#ifdef HETIO +#include "hetio.h" +#endif + +/* + * Sigmode records the current value of the signal handlers for the various + * modes. A value of zero means that the current handler is not known. + * S_HARD_IGN indicates that the signal was ignored on entry to the shell, + */ + +#define S_DFL 1 /* default signal handling (SIG_DFL) */ +#define S_CATCH 2 /* signal is caught */ +#define S_IGN 3 /* signal is ignored (SIG_IGN) */ +#define S_HARD_IGN 4 /* signal is ignored permenantly */ +#define S_RESET 5 /* temporary - to reset a hard ignored sig */ + + +/* trap handler commands */ +char *trap[NSIG]; +/* current value of signal */ +static char sigmode[NSIG - 1]; +/* indicates specified signal received */ +char gotsig[NSIG - 1]; +/* last pending signal */ +volatile sig_atomic_t pendingsigs; +/* do we generate EXSIG events */ +int exsig; + +extern char *signal_names[]; + +#ifdef mkinit +INCLUDE +INIT { + signal(SIGCHLD, SIG_DFL); +} +#endif + +/* + * The trap builtin. + */ + +int +trapcmd(int argc, char **argv) +{ + char *action; + char **ap; + int signo; + + nextopt(nullstr); + ap = argptr; + if (!*ap) { + for (signo = 0 ; signo < NSIG ; signo++) { + if (trap[signo] != NULL) { + out1fmt( + "trap -- %s %s\n", + single_quote(trap[signo]), + signal_names[signo] + ); + } + } + return 0; + } + if (!ap[1]) + action = NULL; + else + action = *ap++; + while (*ap) { + if ((signo = decode_signal(*ap, 0)) < 0) + error("%s: bad trap", *ap); + INTOFF; + if (action) { + if (action[0] == '-' && action[1] == '\0') + action = NULL; + else + action = savestr(action); + } + if (trap[signo]) + ckfree(trap[signo]); + trap[signo] = action; + if (signo != 0) + setsignal(signo); + INTON; + ap++; + } + return 0; +} + + + +/* + * Clear traps on a fork. + */ + +void +clear_traps(void) +{ + char **tp; + + for (tp = trap ; tp < &trap[NSIG] ; tp++) { + if (*tp && **tp) { /* trap not NULL or SIG_IGN */ + INTOFF; + ckfree(*tp); + *tp = NULL; + if (tp != &trap[0]) + setsignal(tp - trap); + INTON; + } + } +} + + + +/* + * Set the signal handler for the specified signal. The routine figures + * out what it should be set to. + */ + +void +setsignal(int signo) +{ + int action; + char *t, tsig; + struct sigaction act; + + if ((t = trap[signo]) == NULL) + action = S_DFL; + else if (*t != '\0') + action = S_CATCH; + else + action = S_IGN; + if (rootshell && action == S_DFL) { + switch (signo) { + case SIGINT: + if (iflag || minusc || sflag == 0) + action = S_CATCH; + break; + case SIGQUIT: +#ifdef DEBUG + if (debug) + break; +#endif + /* FALLTHROUGH */ + case SIGTERM: + if (iflag) + action = S_IGN; + break; +#if JOBS + case SIGTSTP: + case SIGTTOU: + if (mflag) + action = S_IGN; + break; +#endif + } + } + + t = &sigmode[signo - 1]; + tsig = *t; + if (tsig == 0) { + /* + * current setting unknown + */ + if (sigaction(signo, 0, &act) == -1) { + /* + * Pretend it worked; maybe we should give a warning + * here, but other shells don't. We don't alter + * sigmode, so that we retry every time. + */ + return; + } + if (act.sa_handler == SIG_IGN) { + if (mflag && (signo == SIGTSTP || + signo == SIGTTIN || signo == SIGTTOU)) { + tsig = S_IGN; /* don't hard ignore these */ + } else + tsig = S_HARD_IGN; + } else { + tsig = S_RESET; /* force to be set */ + } + } + if (tsig == S_HARD_IGN || tsig == action) + return; + switch (action) { + case S_CATCH: + act.sa_handler = onsig; + break; + case S_IGN: + act.sa_handler = SIG_IGN; + break; + default: + act.sa_handler = SIG_DFL; + } + *t = action; + act.sa_flags = 0; + sigfillset(&act.sa_mask); + sigaction(signo, &act, 0); +} + +/* + * Ignore a signal. + */ + +void +ignoresig(int signo) +{ + if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) { + signal(signo, SIG_IGN); + } + sigmode[signo - 1] = S_HARD_IGN; +} + + + +/* + * Signal handler. + */ + +void +onsig(int signo) +{ + gotsig[signo - 1] = 1; + pendingsigs = signo; + + if (exsig || (signo == SIGINT && !trap[SIGINT])) { + if (!suppressint) + onint(); + intpending = 1; + } +} + + + +/* + * Called to execute a trap. Perhaps we should avoid entering new trap + * handlers while we are executing a trap handler. + */ + +void +dotrap(void) +{ + char *p; + char *q; + int savestatus; + + savestatus = exitstatus; + q = gotsig; + while (pendingsigs = 0, barrier(), (p = memchr(q, 1, NSIG - 1))) { + *p = 0; + p = trap[p - q + 1]; + if (!p) + continue; + evalstring(p); + exitstatus = savestatus; + } +} + + + +/* + * Controls whether the shell is interactive or not. + */ + + +void +setinteractive(int on) +{ + static int is_interactive; + + if (++on == is_interactive) + return; + is_interactive = on; + setsignal(SIGINT); + setsignal(SIGQUIT); + setsignal(SIGTERM); +} + + + +/* + * Called to exit the shell. + */ + +void +exitshell(void) +{ + struct jmploc loc; + char *p; + int status; + int jmp; + +#ifdef HETIO + hetio_reset_term(); +#endif + jmp = setjmp(loc.loc); + status = exitstatus; + TRACE(("pid %d, exitshell(%d)\n", getpid(), status)); + if (jmp) + goto out; + handler = &loc; + if ((p = trap[0]) != NULL && *p != '\0') { + trap[0] = NULL; + evalstring(p); + } + flushall(); +out: + _exit(status); + /* NOTREACHED */ +} + +int decode_signal(const char *string, int minsig) +{ + int signo; + + if (is_number(string)) { + signo = atoi(string); + if (signo >= NSIG) { + return -1; + } + return signo; + } + + for (signo = minsig; signo < NSIG; signo++) { + if (!strcasecmp(string, signal_names[signo])) { + return signo; + } + } + + return -1; +} -- cgit 1.4.1