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. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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35 static char sccsid
[] = "@(#)trap.c 8.5 (Berkeley) 6/5/95";
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
47 #include "nodes.h" /* for other headers */
59 #include "myhistedit.h"
63 * Sigmode records the current value of the signal handlers for the various
64 * modes. A value of zero means that the current handler is not known.
65 * S_HARD_IGN indicates that the signal was ignored on entry to the shell,
68 #define S_DFL 1 /* default signal handling (SIG_DFL) */
69 #define S_CATCH 2 /* signal is caught */
70 #define S_IGN 3 /* signal is ignored (SIG_IGN) */
71 #define S_HARD_IGN 4 /* signal is ignored permanently */
72 #define S_RESET 5 /* temporary - to reset a hard ignored sig */
75 static char sigmode
[NSIG
]; /* current value of signal */
76 volatile sig_atomic_t pendingsig
; /* indicates some signal received */
77 volatile sig_atomic_t pendingsig_waitcmd
; /* indicates wait builtin should be interrupted */
78 static int in_dotrap
; /* do we execute in a trap handler? */
79 static char *volatile trap
[NSIG
]; /* trap handler commands */
80 static volatile sig_atomic_t gotsig
[NSIG
];
81 /* indicates specified signal received */
82 static int ignore_sigchld
; /* Used while handling SIGCHLD traps. */
83 static int last_trapsig
;
85 static int exiting
; /* exitshell() has been called */
86 static int exiting_exitstatus
; /* value passed to exitshell() */
88 static int getsigaction(int, sig_t
*);
92 * Map a string to a signal number.
94 * Note: the signal number may exceed NSIG.
97 sigstring_to_signum(char *sig
)
100 if (is_number(sig
)) {
104 return ((signo
>= 0 && signo
< NSIG
) ? signo
: (-1));
105 } else if (strcasecmp(sig
, "EXIT") == 0) {
110 if (strncasecmp(sig
, "SIG", 3) == 0)
112 for (n
= 1; n
< sys_nsig
; n
++)
113 if (sys_signame
[n
] &&
114 strcasecmp(sys_signame
[n
], sig
) == 0)
122 * Print a list of valid signal names.
130 for (n
= 1; n
< sys_nsig
; n
++) {
131 if (sys_signame
[n
]) {
132 out1fmt("%s", sys_signame
[n
]);
133 outlen
+= strlen(sys_signame
[n
]);
136 outlen
+= 3; /* good enough */
139 if (outlen
> 71 || n
== sys_nsig
- 1) {
153 trapcmd(int argc __unused
, char **argv
)
160 while ((i
= nextopt("l")) != '\0') {
170 for (signo
= 0 ; signo
< sys_nsig
; signo
++) {
171 if (signo
< NSIG
&& trap
[signo
] != NULL
) {
173 out1qstr(trap
[signo
]);
176 } else if (sys_signame
[signo
]) {
177 out1fmt(" %s\n", sys_signame
[signo
]);
179 out1fmt(" %d\n", signo
);
186 if (*argv
&& !is_number(*argv
)) {
187 if (strcmp(*argv
, "-") == 0)
194 for (; *argv
; argv
++) {
195 if ((signo
= sigstring_to_signum(*argv
)) == -1) {
196 warning("bad signal %s", *argv
);
202 action
= savestr(action
);
205 trap
[signo
] = action
;
215 * Clear traps on a fork.
222 for (tp
= trap
; tp
<= &trap
[NSIG
- 1] ; tp
++) {
223 if (*tp
&& **tp
) { /* trap not NULL or SIG_IGN */
228 setsignal(tp
- trap
);
236 * Check if we have any traps enabled.
243 for (tp
= trap
; tp
<= &trap
[NSIG
- 1] ; tp
++) {
244 if (*tp
&& **tp
) /* trap not NULL or SIG_IGN */
251 * Set the signal handler for the specified signal. The routine figures
252 * out what it should be set to.
258 sig_t sigact
= SIG_DFL
;
262 if ((t
= trap
[signo
]) == NULL
)
268 if (action
== S_DFL
) {
285 if (rootshell
&& iflag
)
291 if (rootshell
&& mflag
)
301 * current setting unknown
303 if (!getsigaction(signo
, &sigact
)) {
305 * Pretend it worked; maybe we should give a warning
306 * here, but other shells don't. We don't alter
307 * sigmode, so that we retry every time.
311 if (sigact
== SIG_IGN
) {
312 if (mflag
&& (signo
== SIGTSTP
||
313 signo
== SIGTTIN
|| signo
== SIGTTOU
)) {
314 *t
= S_IGN
; /* don't hard ignore these */
318 *t
= S_RESET
; /* force to be set */
321 if (*t
== S_HARD_IGN
|| *t
== action
)
324 case S_DFL
: sigact
= SIG_DFL
; break;
325 case S_CATCH
: sigact
= onsig
; break;
326 case S_IGN
: sigact
= SIG_IGN
; break;
329 sa
.sa_handler
= sigact
;
331 sigemptyset(&sa
.sa_mask
);
332 sigaction(signo
, &sa
, NULL
);
337 * Return the current setting for sig w/o changing it.
340 getsigaction(int signo
, sig_t
*sigact
)
344 if (sigaction(signo
, (struct sigaction
*)0, &sa
) == -1)
346 *sigact
= (sig_t
) sa
.sa_handler
;
358 if (sigmode
[signo
] == 0)
360 if (sigmode
[signo
] != S_IGN
&& sigmode
[signo
] != S_HARD_IGN
) {
361 signal(signo
, SIG_IGN
);
362 sigmode
[signo
] = S_IGN
;
368 issigchldtrapped(void)
371 return (trap
[SIGCHLD
] != NULL
&& *trap
[SIGCHLD
] != '\0');
382 if (signo
== SIGINT
&& trap
[SIGINT
] == NULL
) {
384 * The !in_dotrap here is safe. The only way we can arrive
385 * here with in_dotrap set is that a trap handler set SIGINT to
386 * SIG_DFL and killed itself.
388 if (suppressint
&& !in_dotrap
)
395 /* If we are currently in a wait builtin, prepare to break it */
396 if (signo
== SIGINT
|| signo
== SIGQUIT
)
397 pendingsig_waitcmd
= signo
;
399 if (trap
[signo
] != NULL
&& trap
[signo
][0] != '\0' &&
400 (signo
!= SIGCHLD
|| !ignore_sigchld
)) {
403 pendingsig_waitcmd
= signo
;
409 * Called to execute a trap. Perhaps we should avoid entering new trap
410 * handlers while we are executing a trap handler.
416 int savestatus
, prev_evalskip
, prev_skipcount
;
421 pendingsig_waitcmd
= 0;
422 for (i
= 1; i
< NSIG
; i
++) {
427 * Ignore SIGCHLD to avoid infinite
428 * recursion if the trap action does
435 * Backup current evalskip
436 * state and reset it before
437 * executing a trap, so that the
438 * trap is not disturbed by an
439 * ongoing break/continue/return
442 prev_evalskip
= evalskip
;
443 prev_skipcount
= skipcount
;
447 savestatus
= exitstatus
;
448 evalstring(trap
[i
], 0);
451 * If such a command was not
452 * already in progress, allow a
453 * break/continue/return in the
454 * trap action to have an effect
458 prev_evalskip
!= 0) {
459 evalskip
= prev_evalskip
;
460 skipcount
= prev_skipcount
;
461 exitstatus
= savestatus
;
478 * Controls whether the shell is interactive or not.
481 setinteractive(int on
)
483 static int is_interactive
= -1;
485 if (on
== is_interactive
)
495 * Called to exit the shell.
498 exitshell(int status
)
500 TRACE(("exitshell(%d) pid=%d\n", status
, getpid()));
502 exiting_exitstatus
= status
;
503 exitshell_savedstatus();
507 exitshell_savedstatus(void)
509 struct jmploc loc1
, loc2
;
515 if (in_dotrap
&& last_trapsig
) {
517 exiting_exitstatus
= sig
+ 128;
519 exiting_exitstatus
= oexitstatus
;
521 exitstatus
= oexitstatus
= exiting_exitstatus
;
522 if (!setjmp(loc1
.loc
)) {
524 if ((p
= trap
[0]) != NULL
&& *p
!= '\0') {
526 * Reset evalskip, or the trap on EXIT could be
527 * interrupted if the last command was a "return".
534 if (!setjmp(loc2
.loc
)) {
535 handler
= &loc2
; /* probably unnecessary */
541 if (sig
!= 0 && sig
!= SIGSTOP
&& sig
!= SIGTSTP
&& sig
!= SIGTTIN
&&
543 signal(sig
, SIG_DFL
);
545 sigaddset(&sigs
, sig
);
546 sigprocmask(SIG_UNBLOCK
, &sigs
, NULL
);
548 /* If the default action is to ignore, fall back to _exit(). */
550 _exit(exiting_exitstatus
);