Contents of /trunk/mkinitrd-magellan/klibc/usr/dash/trap.c
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Fri Apr 24 18:32:46 2009 UTC (15 years, 1 month ago) by niro
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Fri Apr 24 18:32:46 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 8515 byte(s)
-updated to klibc-1.5.15
1 | /*- |
2 | * Copyright (c) 1991, 1993 |
3 | * The Regents of the University of California. All rights reserved. |
4 | * Copyright (c) 1997-2005 |
5 | * Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to Berkeley by |
8 | * Kenneth Almquist. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * 3. Neither the name of the University nor the names of its contributors |
19 | * may be used to endorse or promote products derived from this software |
20 | * without specific prior written permission. |
21 | * |
22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
32 | * SUCH DAMAGE. |
33 | */ |
34 | |
35 | #include <signal.h> |
36 | #include <unistd.h> |
37 | #include <stdlib.h> |
38 | #include <string.h> |
39 | #include <stdio.h> |
40 | |
41 | #include "shell.h" |
42 | #include "main.h" |
43 | #include "nodes.h" /* for other headers */ |
44 | #include "eval.h" |
45 | #include "jobs.h" |
46 | #include "show.h" |
47 | #include "options.h" |
48 | #include "syntax.h" |
49 | #include "output.h" |
50 | #include "memalloc.h" |
51 | #include "error.h" |
52 | #include "trap.h" |
53 | #include "mystring.h" |
54 | |
55 | #ifdef HETIO |
56 | #include "hetio.h" |
57 | #endif |
58 | |
59 | /* |
60 | * Sigmode records the current value of the signal handlers for the various |
61 | * modes. A value of zero means that the current handler is not known. |
62 | * S_HARD_IGN indicates that the signal was ignored on entry to the shell, |
63 | */ |
64 | |
65 | #define S_DFL 1 /* default signal handling (SIG_DFL) */ |
66 | #define S_CATCH 2 /* signal is caught */ |
67 | #define S_IGN 3 /* signal is ignored (SIG_IGN) */ |
68 | #define S_HARD_IGN 4 /* signal is ignored permenantly */ |
69 | #define S_RESET 5 /* temporary - to reset a hard ignored sig */ |
70 | |
71 | |
72 | /* trap handler commands */ |
73 | char *trap[NSIG]; |
74 | /* current value of signal */ |
75 | static char sigmode[NSIG - 1]; |
76 | /* indicates specified signal received */ |
77 | char gotsig[NSIG - 1]; |
78 | /* last pending signal */ |
79 | volatile sig_atomic_t pendingsigs; |
80 | /* do we generate EXSIG events */ |
81 | int exsig; |
82 | |
83 | #ifdef mkinit |
84 | INCLUDE <signal.h> |
85 | INIT { |
86 | signal(SIGCHLD, SIG_DFL); |
87 | } |
88 | #endif |
89 | |
90 | /* |
91 | * The trap builtin. |
92 | */ |
93 | |
94 | int |
95 | trapcmd(int argc, char **argv) |
96 | { |
97 | char *action; |
98 | char **ap; |
99 | int signo; |
100 | |
101 | nextopt(nullstr); |
102 | ap = argptr; |
103 | if (!*ap) { |
104 | for (signo = 0 ; signo < NSIG ; signo++) { |
105 | if (trap[signo] != NULL) { |
106 | out1fmt( |
107 | "trap -- %s %s\n", |
108 | single_quote(trap[signo]), |
109 | signal_name(signo) |
110 | ); |
111 | } |
112 | } |
113 | return 0; |
114 | } |
115 | if (!ap[1]) |
116 | action = NULL; |
117 | else |
118 | action = *ap++; |
119 | while (*ap) { |
120 | if ((signo = decode_signal(*ap, 0)) < 0) |
121 | sh_error("%s: bad trap", *ap); |
122 | INTOFF; |
123 | if (action) { |
124 | if (action[0] == '-' && action[1] == '\0') |
125 | action = NULL; |
126 | else |
127 | action = savestr(action); |
128 | } |
129 | if (trap[signo]) |
130 | ckfree(trap[signo]); |
131 | trap[signo] = action; |
132 | if (signo != 0) |
133 | setsignal(signo); |
134 | INTON; |
135 | ap++; |
136 | } |
137 | return 0; |
138 | } |
139 | |
140 | |
141 | |
142 | /* |
143 | * Clear traps on a fork. |
144 | */ |
145 | |
146 | void |
147 | clear_traps(void) |
148 | { |
149 | char **tp; |
150 | |
151 | for (tp = trap ; tp < &trap[NSIG] ; tp++) { |
152 | if (*tp && **tp) { /* trap not NULL or SIG_IGN */ |
153 | INTOFF; |
154 | ckfree(*tp); |
155 | *tp = NULL; |
156 | if (tp != &trap[0]) |
157 | setsignal(tp - trap); |
158 | INTON; |
159 | } |
160 | } |
161 | } |
162 | |
163 | |
164 | |
165 | /* |
166 | * Set the signal handler for the specified signal. The routine figures |
167 | * out what it should be set to. |
168 | */ |
169 | |
170 | void |
171 | setsignal(int signo) |
172 | { |
173 | int action; |
174 | char *t, tsig; |
175 | struct sigaction act; |
176 | |
177 | if ((t = trap[signo]) == NULL) |
178 | action = S_DFL; |
179 | else if (*t != '\0') |
180 | action = S_CATCH; |
181 | else |
182 | action = S_IGN; |
183 | if (rootshell && action == S_DFL) { |
184 | switch (signo) { |
185 | case SIGINT: |
186 | if (iflag || minusc || sflag == 0) |
187 | action = S_CATCH; |
188 | break; |
189 | case SIGQUIT: |
190 | #ifdef DEBUG |
191 | if (debug) |
192 | break; |
193 | #endif |
194 | /* FALLTHROUGH */ |
195 | case SIGTERM: |
196 | if (iflag) |
197 | action = S_IGN; |
198 | break; |
199 | #if JOBS |
200 | case SIGTSTP: |
201 | case SIGTTOU: |
202 | if (mflag) |
203 | action = S_IGN; |
204 | break; |
205 | #endif |
206 | } |
207 | } |
208 | |
209 | t = &sigmode[signo - 1]; |
210 | tsig = *t; |
211 | if (tsig == 0) { |
212 | /* |
213 | * current setting unknown |
214 | */ |
215 | if (sigaction(signo, 0, &act) == -1) { |
216 | /* |
217 | * Pretend it worked; maybe we should give a warning |
218 | * here, but other shells don't. We don't alter |
219 | * sigmode, so that we retry every time. |
220 | */ |
221 | return; |
222 | } |
223 | if (act.sa_handler == SIG_IGN) { |
224 | if (mflag && (signo == SIGTSTP || |
225 | signo == SIGTTIN || signo == SIGTTOU)) { |
226 | tsig = S_IGN; /* don't hard ignore these */ |
227 | } else |
228 | tsig = S_HARD_IGN; |
229 | } else { |
230 | tsig = S_RESET; /* force to be set */ |
231 | } |
232 | } |
233 | if (tsig == S_HARD_IGN || tsig == action) |
234 | return; |
235 | switch (action) { |
236 | case S_CATCH: |
237 | act.sa_handler = onsig; |
238 | break; |
239 | case S_IGN: |
240 | act.sa_handler = SIG_IGN; |
241 | break; |
242 | default: |
243 | act.sa_handler = SIG_DFL; |
244 | } |
245 | *t = action; |
246 | act.sa_flags = 0; |
247 | sigfillset(&act.sa_mask); |
248 | sigaction(signo, &act, 0); |
249 | } |
250 | |
251 | /* |
252 | * Ignore a signal. |
253 | */ |
254 | |
255 | void |
256 | ignoresig(int signo) |
257 | { |
258 | if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) { |
259 | signal(signo, SIG_IGN); |
260 | } |
261 | sigmode[signo - 1] = S_HARD_IGN; |
262 | } |
263 | |
264 | |
265 | |
266 | /* |
267 | * Signal handler. |
268 | */ |
269 | |
270 | void |
271 | onsig(int signo) |
272 | { |
273 | gotsig[signo - 1] = 1; |
274 | pendingsigs = signo; |
275 | |
276 | if (exsig || (signo == SIGINT && !trap[SIGINT])) { |
277 | if (!suppressint) |
278 | onint(); |
279 | intpending = 1; |
280 | } |
281 | } |
282 | |
283 | |
284 | |
285 | /* |
286 | * Called to execute a trap. Perhaps we should avoid entering new trap |
287 | * handlers while we are executing a trap handler. |
288 | */ |
289 | |
290 | int |
291 | dotrap(void) |
292 | { |
293 | char *p; |
294 | char *q; |
295 | int i; |
296 | int savestatus; |
297 | |
298 | savestatus = exitstatus; |
299 | pendingsigs = 0; |
300 | barrier(); |
301 | |
302 | for (i = 0, q = gotsig; i < NSIG - 1; i++, q++) { |
303 | if (!*q) |
304 | continue; |
305 | *q = 0; |
306 | |
307 | p = trap[i + 1]; |
308 | if (!p) |
309 | continue; |
310 | evalstring(p, SKIPEVAL); |
311 | exitstatus = savestatus; |
312 | if (evalskip) |
313 | return evalskip; |
314 | } |
315 | |
316 | return 0; |
317 | } |
318 | |
319 | |
320 | |
321 | /* |
322 | * Controls whether the shell is interactive or not. |
323 | */ |
324 | |
325 | |
326 | void |
327 | setinteractive(int on) |
328 | { |
329 | static int is_interactive; |
330 | |
331 | if (++on == is_interactive) |
332 | return; |
333 | is_interactive = on; |
334 | setsignal(SIGINT); |
335 | setsignal(SIGQUIT); |
336 | setsignal(SIGTERM); |
337 | } |
338 | |
339 | |
340 | |
341 | /* |
342 | * Called to exit the shell. |
343 | */ |
344 | |
345 | void |
346 | exitshell(void) |
347 | { |
348 | struct jmploc loc; |
349 | char *p; |
350 | int status; |
351 | |
352 | #ifdef HETIO |
353 | hetio_reset_term(); |
354 | #endif |
355 | status = exitstatus; |
356 | TRACE(("pid %d, exitshell(%d)\n", getpid(), status)); |
357 | if (setjmp(loc.loc)) { |
358 | if (exception == EXEXIT) |
359 | _exit(exitstatus); |
360 | goto out; |
361 | } |
362 | handler = &loc; |
363 | if ((p = trap[0])) { |
364 | trap[0] = NULL; |
365 | evalstring(p, 0); |
366 | } |
367 | flushall(); |
368 | out: |
369 | _exit(status); |
370 | /* NOTREACHED */ |
371 | } |
372 | |
373 | /* |
374 | * Decode a signal name |
375 | */ |
376 | int decode_signal(const char *string, int minsig) |
377 | { |
378 | int i; |
379 | |
380 | if (is_number(string)) { |
381 | i = atoi(string); |
382 | if (i >= NSIG) { |
383 | return -1; |
384 | } |
385 | return i; |
386 | } |
387 | |
388 | for ( i = minsig ; i < NSIG ; i++ ) { |
389 | if ( sys_sigabbrev[i] && |
390 | !strcasecmp(string, sys_sigabbrev[i]) ) |
391 | return i; |
392 | } |
393 | |
394 | #ifdef SIGRTMIN |
395 | if ( !strncasecmp(string, "RTMIN", 5) ) { |
396 | char *ep; |
397 | |
398 | if ( string[5] && string[5] != '+' ) |
399 | return -1; |
400 | i = SIGRTMIN + strtol(string+5, &ep, 10); |
401 | if ( *ep || i < SIGRTMIN || i > SIGRTMAX ) |
402 | return -1; |
403 | return i; |
404 | } |
405 | |
406 | if ( !strncasecmp(string, "RTMAX", 5) ) { |
407 | char *ep; |
408 | |
409 | if ( string[5] && string[5] != '-' ) |
410 | return -1; |
411 | i = SIGRTMAX + strtol(string+5, &ep, 10); |
412 | if ( *ep || i < SIGRTMIN || i > SIGRTMAX ) |
413 | return -1; |
414 | return i; |
415 | } |
416 | #endif |
417 | |
418 | return -1; |
419 | } |
420 | |
421 | /* |
422 | * Human-readable signal name |
423 | */ |
424 | const char * |
425 | signal_name(int sig) |
426 | { |
427 | static char buf[64]; |
428 | |
429 | if ( sig < 0 || sig >= NSIG ) { |
430 | return NULL; |
431 | } else if ( sys_sigabbrev[sig] ) { |
432 | return sys_sigabbrev[sig]; |
433 | #ifdef SIGRTMIN |
434 | } else if ( sig >= SIGRTMIN && sig <= SIGRTMAX ) { |
435 | snprintf(buf, sizeof buf, "RTMIN+%d", sig-SIGRTMIN); |
436 | return buf; |
437 | #endif |
438 | } else { |
439 | snprintf(buf, sizeof buf, "%d", sig); |
440 | return buf; |
441 | } |
442 | } |