 @@ -1,596 +1,598 @@
-/*	$NetBSD: trap.c,v 1.40.2.1 2017/07/23 14:58:14 snj Exp $	*/
+/*	$NetBSD: trap.c,v 1.40.2.2 2018/08/25 14:41:21 martin 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.
  */
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)trap.c	8.5 (Berkeley) 6/5/95";
 #else
-__RCSID("$NetBSD: trap.c,v 1.40.2.1 2017/07/23 14:58:14 snj Exp $");
+__RCSID("$NetBSD: trap.c,v 1.40.2.2 2018/08/25 14:41:21 martin Exp $");
 #endif
 #endif /* not lint */
 #include <signal.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.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 "builtins.h"
 #include "syntax.h"
 #include "output.h"
 #include "memalloc.h"
 #include "error.h"
 #include "trap.h"
 #include "mystring.h"
 #include "var.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];		/* trap handler commands */
 MKINIT char sigmode[NSIG];	/* current value of signal */
 static volatile char gotsig[NSIG];/* indicates specified signal received */
 volatile int pendingsigs;	/* indicates some signal received */
 static int getsigaction(int, sig_t *);
 STATIC const char *trap_signame(int);
 /*
  * 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(const char *p)
+{
 	int i;
 	if (is_number(p))
 		return number(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;
+}
 /*
  * return the name of a signal used by the "trap" command
  */
 STATIC const char *
 trap_signame(int signo)
+{
 	static char nbuf[12];
 	const char *p = NULL;
 	if (signo == 0)
 		return "EXIT";
 	if (signo > 0 && signo < NSIG)
 		p = sys_signame[signo];
 	if (p != NULL)
 		return p;
 	(void)snprintf(nbuf, sizeof nbuf, "%d", signo);
 	return nbuf;
+}
 /*
  * Print a list of valid signal names
  */
 static void
 printsignals(void)
+{
 	int n;
 	out1str("EXIT ");
 	for (n = 1; n < NSIG; n++) {
 		out1fmt("%s", trap_signame(n));
 		if ((n == NSIG/2) ||  n == (NSIG - 1))
 			out1str("\n");
 		else
 			out1c(' ');
+	}
+}
 /*
  * The trap builtin.
  */
 int
 trapcmd(int argc, char **argv)
+{
 	char *action;
 	char **ap;
 	int signo;
 	int errs = 0;
 	int printonly = 0;
 	ap = argv + 1;
 	if (argc == 2 && strcmp(*ap, "-l") == 0) {
 		printsignals();
 		return 0;
+	}
 	if (argc == 2 && strcmp(*ap, "-") == 0) {
 		for (signo = 0; signo < NSIG; signo++) {
 			if (trap[signo] == NULL)
 				continue;
 			INTOFF;
 			ckfree(trap[signo]);
 			trap[signo] = NULL;
 			if (signo != 0)
 				setsignal(signo, 0);
 			INTON;
+		}
 		return 0;
+	}
 	if (argc >= 2 && strcmp(*ap, "-p") == 0) {
 		printonly = 1;
 		ap++;
 		argc--;
+	}
 	if (argc > 1 && strcmp(*ap, "--") == 0) {
 		argc--;
 		ap++;
+	}
 	if (argc <= 1) {
 		int count;
 		if (printonly) {
 			for (count = 0, signo = 0 ; signo < NSIG ; signo++)
 				if (trap[signo] == NULL) {
 					if (count == 0)
 						out1str("trap -- -");
 					out1fmt(" %s", trap_signame(signo));
 					/* oh! unlucky 13 */
 					if (++count >= 13) {
 						out1str("\n");
 						count = 0;
+					}
+				}
 			if (count)
 				out1str("\n");
+		}
 		for (count = 0, signo = 0 ; signo < NSIG ; signo++)
 			if (trap[signo] != NULL && trap[signo][0] == '\0') {
 				if (count == 0)
 					out1str("trap -- ''");
 				out1fmt(" %s", trap_signame(signo));
 				/*
 				 * the prefix is 10 bytes, with 4 byte
 				 * signal names (common) we have room in
 				 * the 70 bytes left on a normal line for
 				 * 70/(4+1) signals, that's 14, but to
 				 * allow for the occasional longer sig name
 				 * we output one less...
 				 */
 				if (++count >= 13) {
 					out1str("\n");
 					count = 0;
+				}
+			}
 		if (count)
 			out1str("\n");
 		for (signo = 0 ; signo < NSIG ; signo++)
 			if (trap[signo] != NULL && trap[signo][0] != '\0') {
 				out1str("trap -- ");
 				print_quoted(trap[signo]);
 				out1fmt(" %s\n", trap_signame(signo));
+			}
 		return 0;
+	}
 	action = NULL;
 	if (!printonly && !is_number(*ap)) {
 		if ((*ap)[0] == '-' && (*ap)[1] == '\0')
 			ap++;			/* reset to default */
 		else
 			action = *ap++;		/* can be '' for "ignore" */
 		argc--;
+	}
 	if (argc < 2) {		/* there must be at least 1 condition */
 		out2str("Usage: trap [-l]\n"
 			"       trap -p [condition ...]\n"
 			"       trap action condition ...\n"
 			"       trap N condition ...\n");
 		return 2;
+	}
 	while (*ap) {
 		signo = signame_to_signum(*ap);
 		if (signo < 0 || signo >= NSIG) {
 			/* This is not a fatal error, so sayeth posix */
 			outfmt(out2, "trap: '%s' bad condition\n", *ap);
 			errs = 1;
 			ap++;
 			continue;
+		}
 		ap++;
 		if (printonly) {
 			out1str("trap -- ");
 			if (trap[signo] == NULL)
 				out1str("-");
 			else
 				print_quoted(trap[signo]);
 			out1fmt(" %s\n", trap_signame(signo));
 			continue;
+		}
 		INTOFF;
 		if (action)
 			action = savestr(action);
 		if (trap[signo])
 			ckfree(trap[signo]);
 		trap[signo] = action;
 		if (signo != 0)
 			setsignal(signo, 0);
 		INTON;
+	}
 	return errs;
+}
 /*
  * 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(int vforked)
+{
 	char **tp;
 	for (tp = trap ; tp < &trap[NSIG] ; tp++) {
 		if (*tp && **tp) {	/* trap not NULL or SIG_IGN */
 			INTOFF;
 			if (!vforked) {
 				ckfree(*tp);
 				*tp = NULL;
+			}
 			if (tp != &trap[0])
 				setsignal(tp - trap, vforked);
 			INTON;
+		}
+	}
+}
 /*
  * Set the signal handler for the specified signal.  The routine figures
  * out what it should be set to.
  */
 sig_t
 setsignal(int signo, int vforked)
+{
 	int action;
 	sig_t sigact = SIG_DFL, sig;
 	char *t, tsig;
 	if ((t = trap[signo]) == NULL)
 		action = S_DFL;
 	else if (*t != '\0')
 		action = S_CATCH;
 	else
 		action = S_IGN;
 	if (rootshell && !vforked && 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 (!getsigaction(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 0;
+		}
 		if (sigact == SIG_IGN) {
 			/*
 			 * POSIX 3.14.13 states that non-interactive shells
 			 * should ignore trap commands for signals that were
 			 * ignored upon entry, and leaves the behavior
 			 * unspecified for interactive shells. On interactive
 			 * shells, or if job control is on, and we have a job
 			 * control related signal, we allow the trap to work.
+			 *
 			 * This change allows us to be POSIX compliant, and
 			 * at the same time override the default behavior if
 			 * we need to by setting the interactive flag.
 			 */
 			if ((mflag && (signo == SIGTSTP ||
 			     signo == SIGTTIN || signo == SIGTTOU)) || iflag) {
 				tsig = S_IGN;
 			} else
 				tsig = S_HARD_IGN;
 		} else {
 			tsig = S_RESET;	/* force to be set */
+		}
+	}
 	if (tsig == S_HARD_IGN || tsig == action)
 		return 0;
 	switch (action) {
 		case S_DFL:	sigact = SIG_DFL;	break;
 		case S_CATCH:  	sigact = onsig;		break;
 		case S_IGN:	sigact = SIG_IGN;	break;
+	}
 	sig = signal(signo, sigact);
 	if (sig != SIG_ERR) {
 		sigset_t ss;
 		if (!vforked)
 			*t = action;
 		if (action == S_CATCH)
 			(void)siginterrupt(signo, 1);
 		/*
 		 * If our parent accidentally blocked signals for
 		 * us make sure we unblock them
 		 */
 		(void)sigemptyset(&ss);
 		(void)sigaddset(&ss, signo);
 		(void)sigprocmask(SIG_UNBLOCK, &ss, NULL);
+	}
 	return sig;
+}
 /*
  * Return the current setting for sig w/o changing it.
  */
 static int
 getsigaction(int signo, sig_t *sigact)
+{
 	struct sigaction sa;
 	if (sigaction(signo, (struct sigaction *)0, &sa) == -1)
 		return 0;
 	*sigact = (sig_t) sa.sa_handler;
 	return 1;
+}
 /*
  * Ignore a signal.
  */
 void
 ignoresig(int signo, int vforked)
+{
 	if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) {
 		signal(signo, SIG_IGN);
+	}
 	if (!vforked)
 		sigmode[signo - 1] = S_HARD_IGN;
+}
 #ifdef mkinit
 INCLUDE <signal.h>
 INCLUDE "trap.h"
 SHELLPROC {
 	char *sm;
 	clear_traps(0);
 	for (sm = sigmode ; sm < sigmode + NSIG ; sm++) {
 		if (*sm == S_IGN)
 			*sm = S_HARD_IGN;
+	}
+}
 #endif
 /*
  * Signal handler.
  */
 void
 onsig(int signo)
+{
 	CTRACE(DBG_SIG, ("Signal %d, had: pending %d, gotsig[%d]=%d\n",
 	    signo, pendingsigs, signo, gotsig[signo]));
 	signal(signo, onsig);
 	if (signo == SIGINT && trap[SIGINT] == NULL) {
 		onint();
 		return;
+	}
 	gotsig[signo] = 1;
 	pendingsigs++;
+}
 /*
  * Called to execute a trap.  Perhaps we should avoid entering new trap
  * handlers while we are executing a trap handler.
  */
 void
 dotrap(void)
+{
 	int i;
 	int savestatus;
 	char *tr;
 	for (;;) {
 		for (i = 1 ; ; i++) {
 			if (i >= NSIG) {
 				pendingsigs = 0;
 				return;
+			}
 			if (gotsig[i])
 				break;
+		}
 		gotsig[i] = 0;
 		savestatus=exitstatus;
 		CTRACE(DBG_TRAP|DBG_SIG, ("dotrap %d: \"%s\"\n", i,
 		    trap[i] ? trap[i] : "-NULL-"));
-		tr = savestr(trap[i]);		/* trap code may free trap[i] */
+		if ((tr = trap[i]) != NULL) {
-		evalstring(tr, 0);
+			tr = savestr(tr);	/* trap code may free trap[i] */
-		ckfree(tr);
+			evalstring(tr, 0);
 			ckfree(tr);
+		}
 		exitstatus=savestatus;
+	}
+}
 int
 lastsig(void)
+{
 	int i;
 	for (i = NSIG; --i > 0; )
 		if (gotsig[i])
 			return i;
 	return SIGINT;	/* XXX */
+}
 /*
  * Controls whether the shell is interactive or not.
  */
 void
 setinteractive(int on)
+{
 	static int is_interactive;
 	if (on == is_interactive)
 		return;
 	setsignal(SIGINT, 0);
 	setsignal(SIGQUIT, 0);
 	setsignal(SIGTERM, 0);
 	is_interactive = on;
+}
 /*
  * Called to exit the shell.
  */
 void
 exitshell(int status)
+{
 	struct jmploc loc1, loc2;
 	char *p;
 	CTRACE(DBG_ERRS|DBG_PROCS|DBG_CMDS|DBG_TRAP,
 	    ("pid %d, exitshell(%d)\n", getpid(), status));
 	if (setjmp(loc1.loc)) {
 		goto l1;
+	}
 	if (setjmp(loc2.loc)) {
 		goto l2;
+	}
 	handler = &loc1;
 	if ((p = trap[0]) != NULL && *p != '\0') {
 		trap[0] = NULL;
 		VTRACE(DBG_TRAP, ("exit trap: \"%s\"\n", p));
 		evalstring(p, 0);
+	}
  l1:	handler = &loc2;			/* probably unnecessary */
 	flushall();
 #if JOBS
 	setjobctl(0);
 #endif
  l2:	_exit(status);
 	/* NOTREACHED */
+}