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Diffstat (limited to 'src/kash/trap.c')
| -rw-r--r-- | src/kash/trap.c | 471 |
1 files changed, 471 insertions, 0 deletions
diff --git a/src/kash/trap.c b/src/kash/trap.c new file mode 100644 index 0000000..df2d4a3 --- /dev/null +++ b/src/kash/trap.c @@ -0,0 +1,471 @@ +/* $NetBSD: trap.c,v 1.31 2005/01/11 19:38:57 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. 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. + */ + +#if 0 +#ifndef lint +static char sccsid[] = "@(#)trap.c 8.5 (Berkeley) 6/5/95"; +#else +__RCSID("$NetBSD: trap.c,v 1.31 2005/01/11 19:38:57 christos Exp $"); +#endif /* not lint */ +#endif + +#include <stdlib.h> + +#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" +#include "var.h" +#include "shinstance.h" + + +/* + * 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 */ + + +//char *trap[NSIG+1]; /* trap handler commands */ +//MKINIT char sigmode[NSIG]; /* current value of signal */ +//char gotsig[NSIG]; /* indicates specified signal received */ +//int pendingsigs; /* indicates some signal received */ + +static int getsigaction(shinstance *, int, shsig_t *); + +#ifndef SH_FORKED_MODE +void +subshellinittrap(shinstance *psh, shinstance *inherit) +{ + /* The forkchild calls clear_traps(), we have to emulate that here. */ + unsigned i; + memcpy(psh->sigmode, inherit->sigmode, sizeof(psh->sigmode)); + for (i = 0; i < K_ELEMENTS(inherit->trap); i++) { + const char *src = inherit->trap[i]; + if (!src) { + } else if (i > 0) { + setsignal(psh, i); + } + } +} +#endif + + +/* + * return the signal number described by `p' (as a number or a name) + * or -1 if it isn't one + */ + +static int +signame_to_signum(shinstance *psh, const char *p) +{ + int i; + + if (is_number(p)) + return number(psh, p); + + if (strcasecmp(p, "exit") == 0 ) + return 0; + + if (strncasecmp(p, "sig", 3) == 0) + p += 3; + + for (i = 0; i < NSIG; ++i) + if (strcasecmp(p, sys_signame[i]) == 0) + return i; + return -1; +} + +/* + * Print a list of valid signal names + */ +static void +printsignals(shinstance *psh) +{ + int n; + + out1str(psh, "EXIT "); + + for (n = 1; n < NSIG; n++) { + out1fmt(psh, "%s", sys_signame[n]); + if ((n == NSIG/2) || n == (NSIG - 1)) + out1str(psh, "\n"); + else + out1c(psh, ' '); + } +} + +/* + * The trap builtin. + */ + +int +trapcmd(shinstance *psh, int argc, char **argv) +{ + char *action; + char **ap; + int signo; + + if (argc <= 1) { + for (signo = 0 ; signo <= NSIG ; signo++) + if (psh->trap[signo] != NULL) { + out1fmt(psh, "trap -- "); + print_quoted(psh, psh->trap[signo]); + out1fmt(psh, " %s\n", + (signo) ? sys_signame[signo] : "EXIT"); + } + return 0; + } + ap = argv + 1; + + action = NULL; + + if (strcmp(*ap, "--") == 0) + if (*++ap == NULL) + return 0; + + if (signame_to_signum(psh, *ap) == -1) { + if ((*ap)[0] == '-') { + if ((*ap)[1] == '\0') + ap++; + else if ((*ap)[1] == 'l' && (*ap)[2] == '\0') { + printsignals(psh); + return 0; + } + else + error(psh, "bad option %s\n", *ap); + } + else + action = *ap++; + } + + while (*ap) { + if (is_number(*ap)) + signo = number(psh, *ap); + else + signo = signame_to_signum(psh, *ap); + + if (signo < 0 || signo > NSIG) + error(psh, "%s: bad trap", *ap); + + INTOFF; + if (action) + action = savestr(psh, action); + + if (psh->trap[signo]) + ckfree(psh, psh->trap[signo]); + + psh->trap[signo] = action; + + if (signo != 0) + setsignal(psh, signo); + INTON; + ap++; + } + return 0; +} + + + +/* + * Clear traps on a fork or vfork. + * Takes one arg vfork, to tell it to not be destructive of + * the parents variables. + */ + +void +clear_traps(shinstance *psh) +{ + char **tp; + + for (tp = psh->trap ; tp <= &psh->trap[NSIG] ; tp++) { + if (*tp && **tp) { /* trap not NULL or SIG_IGN */ + INTOFF; + ckfree(psh, *tp); + *tp = NULL; + if (tp != &psh->trap[0]) + setsignal(psh, (int)(tp - psh->trap)); + INTON; + } + } +} + + + +/* + * Set the signal handler for the specified signal. The routine figures + * out what it should be set to. + */ + +void +setsignal(shinstance *psh, int signo) +{ + int action; + shsig_t sigact = SH_SIG_DFL; + char *t, tsig; + + if ((t = psh->trap[signo]) == NULL) + action = S_DFL; + else if (*t != '\0') + action = S_CATCH; + else + action = S_IGN; + if (psh->rootshell && action == S_DFL) { + switch (signo) { + case SIGINT: + if (iflag(psh) || psh->minusc || sflag(psh) == 0) + action = S_CATCH; + break; + case SIGQUIT: +#ifdef DEBUG + if (debug(psh)) + break; +#endif + /* FALLTHROUGH */ + case SIGTERM: + if (iflag(psh)) + action = S_IGN; + break; +#if JOBS + case SIGTSTP: + case SIGTTOU: + if (mflag(psh)) + action = S_IGN; + break; +#endif + } + } + + t = &psh->sigmode[signo - 1]; + tsig = *t; + if (tsig == 0) { + /* + * current setting unknown + */ + if (!getsigaction(psh, signo, &sigact)) { + /* + * 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 (sigact == SH_SIG_IGN) { + if (mflag(psh) && (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_DFL: sigact = SH_SIG_DFL; break; + case S_CATCH: sigact = onsig; break; + case S_IGN: sigact = SH_SIG_IGN; break; + } + *t = action; + sh_siginterrupt(psh, signo, 1); + sh_signal(psh, signo, sigact); +} + +/* + * Return the current setting for sig w/o changing it. + */ +static int +getsigaction(shinstance *psh, int signo, shsig_t *sigact) +{ + struct shsigaction sa; + + if (sh_sigaction(psh, signo, NULL, &sa) == -1) + return 0; + *sigact = (shsig_t)sa.sh_handler; + return 1; +} + +/* + * Ignore a signal. + */ + +void +ignoresig(shinstance *psh, int signo) +{ + if (psh->sigmode[signo - 1] != S_IGN && psh->sigmode[signo - 1] != S_HARD_IGN) { + sh_signal(psh, signo, SH_SIG_IGN); + } + psh->sigmode[signo - 1] = S_HARD_IGN; +} + + +#ifdef mkinit +INCLUDE <signal.h> +INCLUDE "trap.h" + +SHELLPROC { + char *sm; + + clear_traps(psh); + for (sm = psh->sigmode ; sm < psh->sigmode + NSIG ; sm++) { + if (*sm == S_IGN) + *sm = S_HARD_IGN; + } +} +#endif + + + +/* + * Signal handler. + */ + +void +onsig(shinstance *psh, int signo) +{ + sh_signal(psh, signo, onsig); + if (signo == SIGINT && psh->trap[SIGINT] == NULL) { + onint(psh); + return; + } + psh->gotsig[signo - 1] = 1; + psh->pendingsigs++; +} + + + +/* + * Called to execute a trap. Perhaps we should avoid entering new trap + * handlers while we are executing a trap handler. + */ + +void +dotrap(shinstance *psh) +{ + int i; + int savestatus; + + for (;;) { + for (i = 1 ; ; i++) { + if (psh->gotsig[i - 1]) + break; + if (i >= NSIG) + goto done; + } + psh->gotsig[i - 1] = 0; + savestatus=psh->exitstatus; + evalstring(psh, psh->trap[i], 0); + psh->exitstatus=savestatus; + } +done: + psh->pendingsigs = 0; +} + + + +/* + * Controls whether the shell is interactive or not. + */ + + +void +setinteractive(shinstance *psh, int on) +{ + static int is_interactive; + + if (on == is_interactive) + return; + setsignal(psh, SIGINT); + setsignal(psh, SIGQUIT); + setsignal(psh, SIGTERM); + is_interactive = on; +} + + + +/* + * Called to exit the shell. + */ + +int +exitshell2(shinstance *psh, int status) +{ + struct jmploc loc1, loc2; + char *p; + + TRACE((psh, "pid %" SHPID_PRI ", exitshell(%d)\n", sh_getpid(psh), status)); + if (setjmp(loc1.loc)) { + goto l1; + } + if (setjmp(loc2.loc)) { + goto l2; + } + psh->handler = &loc1; + if ((p = psh->trap[0]) != NULL && *p != '\0') { + psh->trap[0] = NULL; + evalstring(psh, p, 0); + } +l1: + psh->handler = &loc2; /* probably unnecessary */ + output_flushall(psh); +#if JOBS + setjobctl(psh, 0); +#endif +l2: + return status; +} + +SH_NORETURN_1 void +exitshell(shinstance *psh, int status) +{ + sh__exit(psh, exitshell2(psh, status)); + /* NOTREACHED */ +} + |