sh: Fix $? in heredocs on simple commands.
[dragonfly.git] / bin / sh / eval.c
CommitLineData
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1/*-
2 * Copyright (c) 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
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. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
1de703da
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35 *
36 * @(#)eval.c 8.9 (Berkeley) 6/8/95
87838cc9 37 * $FreeBSD: src/bin/sh/eval.c,v 1.107 2011/06/05 14:13:15 jilles Exp $
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38 */
39
bec497dd 40#include <sys/time.h>
0d5aaed6 41#include <sys/resource.h>
f75716ef
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42#include <sys/wait.h> /* For WIFSIGNALED(status) */
43
44#include <errno.h>
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45#include <paths.h>
46#include <signal.h>
f75716ef 47#include <stdlib.h>
984263bc 48#include <unistd.h>
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49
50/*
51 * Evaluate a command.
52 */
53
54#include "shell.h"
55#include "nodes.h"
56#include "syntax.h"
57#include "expand.h"
58#include "parser.h"
59#include "jobs.h"
60#include "eval.h"
61#include "builtins.h"
62#include "options.h"
63#include "exec.h"
64#include "redir.h"
65#include "input.h"
66#include "output.h"
67#include "trap.h"
68#include "var.h"
69#include "memalloc.h"
70#include "error.h"
71#include "show.h"
72#include "mystring.h"
73#ifndef NO_HISTORY
74#include "myhistedit.h"
75#endif
76
77
934863d7 78int evalskip; /* set if we are skipping commands */
99512ac4 79static int skipcount; /* number of levels to skip */
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80MKINIT int loopnest; /* current loop nesting level */
81int funcnest; /* depth of function calls */
99512ac4 82static int builtin_flags; /* evalcommand flags for builtins */
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83
84
492efe05 85const char *commandname;
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86struct strlist *cmdenviron;
87int exitstatus; /* exit status of last command */
88int oexitstatus; /* saved exit status */
89
90
99512ac4
PA
91static void evalloop(union node *, int);
92static void evalfor(union node *, int);
93static void evalcase(union node *, int);
94static void evalsubshell(union node *, int);
95static void evalredir(union node *, int);
96static void expredir(union node *);
97static void evalpipe(union node *);
98static int is_valid_fast_cmdsubst(union node *n);
99static void evalcommand(union node *, int, struct backcmd *);
100static void prehash(union node *);
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101
102
103/*
104 * Called to reset things after an exception.
105 */
106
107#ifdef mkinit
108INCLUDE "eval.h"
109
110RESET {
111 evalskip = 0;
112 loopnest = 0;
113 funcnest = 0;
114}
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115#endif
116
117
118
119/*
120 * The eval command.
121 */
122
123int
124evalcmd(int argc, char **argv)
125{
126 char *p;
127 char *concat;
128 char **ap;
129
130 if (argc > 1) {
131 p = argv[1];
132 if (argc > 2) {
133 STARTSTACKSTR(concat);
134 ap = argv + 2;
135 for (;;) {
99512ac4 136 STPUTS(p, concat);
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137 if ((p = *ap++) == NULL)
138 break;
139 STPUTC(' ', concat);
140 }
141 STPUTC('\0', concat);
142 p = grabstackstr(concat);
143 }
99512ac4
PA
144 evalstring(p, builtin_flags & EV_TESTED);
145 } else
146 exitstatus = 0;
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147 return exitstatus;
148}
149
150
151/*
152 * Execute a command or commands contained in a string.
153 */
154
155void
99512ac4 156evalstring(char *s, int flags)
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157{
158 union node *n;
159 struct stackmark smark;
99512ac4
PA
160 int flags_exit;
161 int any;
984263bc 162
99512ac4
PA
163 flags_exit = flags & EV_EXIT;
164 flags &= ~EV_EXIT;
165 any = 0;
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166 setstackmark(&smark);
167 setinputstring(s, 1);
168 while ((n = parsecmd(0)) != NEOF) {
276d61f5 169 if (n != NULL && !nflag) {
99512ac4
PA
170 if (flags_exit && preadateof())
171 evaltree(n, flags | EV_EXIT);
172 else
173 evaltree(n, flags);
174 any = 1;
175 }
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176 popstackmark(&smark);
177 }
178 popfile();
179 popstackmark(&smark);
99512ac4
PA
180 if (!any)
181 exitstatus = 0;
182 if (flags_exit)
2b23d27f 183 exraise(EXEXIT);
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184}
185
186
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187/*
188 * Evaluate a parse tree. The value is left in the global variable
189 * exitstatus.
190 */
191
192void
193evaltree(union node *n, int flags)
194{
6a3f0d3d 195 int do_etest;
99512ac4 196 union node *next;
6a3f0d3d
SS
197
198 do_etest = 0;
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199 if (n == NULL) {
200 TRACE(("evaltree(NULL) called\n"));
201 exitstatus = 0;
202 goto out;
203 }
99512ac4
PA
204 do {
205 next = NULL;
984263bc 206#ifndef NO_HISTORY
99512ac4 207 displayhist = 1; /* show history substitutions done with fc */
984263bc 208#endif
99512ac4
PA
209 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type));
210 switch (n->type) {
211 case NSEMI:
212 evaltree(n->nbinary.ch1, flags & ~EV_EXIT);
213 if (evalskip)
214 goto out;
215 next = n->nbinary.ch2;
216 break;
217 case NAND:
218 evaltree(n->nbinary.ch1, EV_TESTED);
219 if (evalskip || exitstatus != 0) {
220 goto out;
221 }
222 next = n->nbinary.ch2;
223 break;
224 case NOR:
225 evaltree(n->nbinary.ch1, EV_TESTED);
226 if (evalskip || exitstatus == 0)
227 goto out;
228 next = n->nbinary.ch2;
229 break;
230 case NREDIR:
231 evalredir(n, flags);
232 break;
233 case NSUBSHELL:
234 evalsubshell(n, flags);
235 do_etest = !(flags & EV_TESTED);
236 break;
237 case NBACKGND:
238 evalsubshell(n, flags);
239 break;
240 case NIF: {
241 evaltree(n->nif.test, EV_TESTED);
242 if (evalskip)
243 goto out;
244 if (exitstatus == 0)
245 next = n->nif.ifpart;
246 else if (n->nif.elsepart)
247 next = n->nif.elsepart;
248 else
249 exitstatus = 0;
250 break;
984263bc 251 }
99512ac4
PA
252 case NWHILE:
253 case NUNTIL:
254 evalloop(n, flags & ~EV_EXIT);
255 break;
256 case NFOR:
257 evalfor(n, flags & ~EV_EXIT);
258 break;
259 case NCASE:
260 evalcase(n, flags);
261 break;
262 case NDEFUN:
263 defun(n->narg.text, n->narg.next);
984263bc 264 exitstatus = 0;
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PA
265 break;
266 case NNOT:
267 evaltree(n->nnot.com, EV_TESTED);
268 exitstatus = !exitstatus;
269 break;
270
271 case NPIPE:
272 evalpipe(n);
273 do_etest = !(flags & EV_TESTED);
274 break;
275 case NCMD:
276 evalcommand(n, flags, NULL);
277 do_etest = !(flags & EV_TESTED);
278 break;
279 default:
280 out1fmt("Node type = %d\n", n->type);
281 flushout(&output);
282 break;
283 }
284 n = next;
285 } while (n != NULL);
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286out:
287 if (pendingsigs)
288 dotrap();
2b23d27f 289 if (eflag && exitstatus != 0 && do_etest)
984263bc 290 exitshell(exitstatus);
2b23d27f
PA
291 if (flags & EV_EXIT)
292 exraise(EXEXIT);
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293}
294
295
99512ac4 296static void
6a3f0d3d 297evalloop(union node *n, int flags)
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298{
299 int status;
300
301 loopnest++;
302 status = 0;
303 for (;;) {
304 evaltree(n->nbinary.ch1, EV_TESTED);
305 if (evalskip) {
306skipping: if (evalskip == SKIPCONT && --skipcount <= 0) {
307 evalskip = 0;
308 continue;
309 }
310 if (evalskip == SKIPBREAK && --skipcount <= 0)
311 evalskip = 0;
99512ac4
PA
312 if (evalskip == SKIPFUNC || evalskip == SKIPFILE)
313 status = exitstatus;
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314 break;
315 }
316 if (n->type == NWHILE) {
317 if (exitstatus != 0)
318 break;
319 } else {
320 if (exitstatus == 0)
321 break;
322 }
6a3f0d3d 323 evaltree(n->nbinary.ch2, flags);
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324 status = exitstatus;
325 if (evalskip)
326 goto skipping;
327 }
328 loopnest--;
329 exitstatus = status;
330}
331
332
333
99512ac4 334static void
6a3f0d3d 335evalfor(union node *n, int flags)
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336{
337 struct arglist arglist;
338 union node *argp;
339 struct strlist *sp;
340 struct stackmark smark;
341
342 setstackmark(&smark);
343 arglist.lastp = &arglist.list;
344 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
345 oexitstatus = exitstatus;
346 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
347 if (evalskip)
348 goto out;
349 }
350 *arglist.lastp = NULL;
351
352 exitstatus = 0;
353 loopnest++;
354 for (sp = arglist.list ; sp ; sp = sp->next) {
355 setvar(n->nfor.var, sp->text, 0);
6a3f0d3d 356 evaltree(n->nfor.body, flags);
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357 if (evalskip) {
358 if (evalskip == SKIPCONT && --skipcount <= 0) {
359 evalskip = 0;
360 continue;
361 }
362 if (evalskip == SKIPBREAK && --skipcount <= 0)
363 evalskip = 0;
364 break;
365 }
366 }
367 loopnest--;
368out:
369 popstackmark(&smark);
370}
371
372
373
99512ac4 374static void
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375evalcase(union node *n, int flags)
376{
377 union node *cp;
378 union node *patp;
379 struct arglist arglist;
380 struct stackmark smark;
381
382 setstackmark(&smark);
383 arglist.lastp = &arglist.list;
384 oexitstatus = exitstatus;
99512ac4 385 exitstatus = 0;
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386 expandarg(n->ncase.expr, &arglist, EXP_TILDE);
387 for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
388 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
389 if (casematch(patp, arglist.list->text)) {
390 if (evalskip == 0) {
391 evaltree(cp->nclist.body, flags);
392 }
393 goto out;
394 }
395 }
396 }
397out:
398 popstackmark(&smark);
399}
400
401
402
403/*
404 * Kick off a subshell to evaluate a tree.
405 */
406
99512ac4 407static void
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408evalsubshell(union node *n, int flags)
409{
410 struct job *jp;
411 int backgnd = (n->type == NBACKGND);
412
87838cc9 413 oexitstatus = exitstatus;
984263bc 414 expredir(n->nredir.redirect);
99512ac4
PA
415 if ((!backgnd && flags & EV_EXIT && !have_traps()) ||
416 forkshell(jp = makejob(n, 1), n, backgnd) == 0) {
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MD
417 if (backgnd)
418 flags &=~ EV_TESTED;
419 redirect(n->nredir.redirect, 0);
420 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */
99512ac4 421 } else if (!backgnd) {
984263bc 422 INTOFF;
2038fb68 423 exitstatus = waitforjob(jp, NULL);
984263bc 424 INTON;
5d4731c8
PA
425 } else
426 exitstatus = 0;
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MD
427}
428
429
99512ac4
PA
430/*
431 * Evaluate a redirected compound command.
432 */
433
434static void
435evalredir(union node *n, int flags)
436{
437 struct jmploc jmploc;
438 struct jmploc *savehandler;
439 volatile int in_redirect = 1;
440
87838cc9 441 oexitstatus = exitstatus;
99512ac4
PA
442 expredir(n->nredir.redirect);
443 savehandler = handler;
444 if (setjmp(jmploc.loc)) {
445 int e;
446
447 handler = savehandler;
448 e = exception;
2b23d27f 449 popredir();
99512ac4 450 if (e == EXERROR || e == EXEXEC) {
99512ac4
PA
451 if (in_redirect) {
452 exitstatus = 2;
453 return;
454 }
455 }
456 longjmp(handler->loc, 1);
457 } else {
458 INTOFF;
459 handler = &jmploc;
460 redirect(n->nredir.redirect, REDIR_PUSH);
461 in_redirect = 0;
462 INTON;
463 evaltree(n->nredir.n, flags);
464 }
465 INTOFF;
466 handler = savehandler;
467 popredir();
468 INTON;
469}
470
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471
472/*
473 * Compute the names of the files in a redirection list.
474 */
475
99512ac4 476static void
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477expredir(union node *n)
478{
479 union node *redir;
480
481 for (redir = n ; redir ; redir = redir->nfile.next) {
482 struct arglist fn;
483 fn.lastp = &fn.list;
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484 switch (redir->type) {
485 case NFROM:
486 case NTO:
487 case NFROMTO:
488 case NAPPEND:
489 case NCLOBBER:
490 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
491 redir->nfile.expfname = fn.list->text;
492 break;
493 case NFROMFD:
494 case NTOFD:
495 if (redir->ndup.vname) {
99512ac4 496 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
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497 fixredir(redir, fn.list->text, 1);
498 }
499 break;
500 }
501 }
502}
503
504
505
506/*
507 * Evaluate a pipeline. All the processes in the pipeline are children
508 * of the process creating the pipeline. (This differs from some versions
509 * of the shell, which make the last process in a pipeline the parent
510 * of all the rest.)
511 */
512
99512ac4 513static void
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MD
514evalpipe(union node *n)
515{
516 struct job *jp;
517 struct nodelist *lp;
518 int pipelen;
519 int prevfd;
520 int pip[2];
521
0d5aaed6 522 TRACE(("evalpipe(%p) called\n", (void *)n));
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MD
523 pipelen = 0;
524 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
525 pipelen++;
526 INTOFF;
527 jp = makejob(n, pipelen);
528 prevfd = -1;
529 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
530 prehash(lp->n);
531 pip[1] = -1;
532 if (lp->next) {
533 if (pipe(pip) < 0) {
42ccfa71
SS
534 if (prevfd >= 0)
535 close(prevfd);
984263bc
MD
536 error("Pipe call failed: %s", strerror(errno));
537 }
538 }
539 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
540 INTON;
541 if (prevfd > 0) {
0d5aaed6 542 dup2(prevfd, 0);
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543 close(prevfd);
544 }
545 if (pip[1] >= 0) {
546 if (!(prevfd >= 0 && pip[0] == 0))
547 close(pip[0]);
548 if (pip[1] != 1) {
0d5aaed6 549 dup2(pip[1], 1);
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550 close(pip[1]);
551 }
552 }
553 evaltree(lp->n, EV_EXIT);
554 }
555 if (prevfd >= 0)
556 close(prevfd);
557 prevfd = pip[0];
d23796a8
PA
558 if (pip[1] != -1)
559 close(pip[1]);
984263bc
MD
560 }
561 INTON;
562 if (n->npipe.backgnd == 0) {
563 INTOFF;
2038fb68 564 exitstatus = waitforjob(jp, NULL);
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MD
565 TRACE(("evalpipe: job done exit status %d\n", exitstatus));
566 INTON;
5d4731c8
PA
567 } else
568 exitstatus = 0;
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MD
569}
570
571
572
99512ac4
PA
573static int
574is_valid_fast_cmdsubst(union node *n)
575{
576 union node *argp;
577
578 if (n->type != NCMD)
579 return 0;
580 for (argp = n->ncmd.args ; argp ; argp = argp->narg.next)
581 if (expandhassideeffects(argp->narg.text))
582 return 0;
583 return 1;
584}
585
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586/*
587 * Execute a command inside back quotes. If it's a builtin command, we
588 * want to save its output in a block obtained from malloc. Otherwise
589 * we fork off a subprocess and get the output of the command via a pipe.
590 * Should be called with interrupts off.
591 */
592
593void
594evalbackcmd(union node *n, struct backcmd *result)
595{
596 int pip[2];
597 struct job *jp;
598 struct stackmark smark; /* unnecessary */
99512ac4
PA
599 struct jmploc jmploc;
600 struct jmploc *savehandler;
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MD
601
602 setstackmark(&smark);
603 result->fd = -1;
604 result->buf = NULL;
605 result->nleft = 0;
606 result->jp = NULL;
607 if (n == NULL) {
608 exitstatus = 0;
609 goto out;
610 }
99512ac4 611 if (is_valid_fast_cmdsubst(n)) {
984263bc 612 exitstatus = oexitstatus;
99512ac4
PA
613 savehandler = handler;
614 if (setjmp(jmploc.loc)) {
615 if (exception == EXERROR || exception == EXEXEC)
616 exitstatus = 2;
617 else if (exception != 0) {
618 handler = savehandler;
619 longjmp(handler->loc, 1);
620 }
621 } else {
622 handler = &jmploc;
623 evalcommand(n, EV_BACKCMD, result);
624 }
625 handler = savehandler;
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MD
626 } else {
627 exitstatus = 0;
628 if (pipe(pip) < 0)
629 error("Pipe call failed: %s", strerror(errno));
630 jp = makejob(n, 1);
631 if (forkshell(jp, n, FORK_NOJOB) == 0) {
632 FORCEINTON;
633 close(pip[0]);
634 if (pip[1] != 1) {
0d5aaed6 635 dup2(pip[1], 1);
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636 close(pip[1]);
637 }
638 evaltree(n, EV_EXIT);
639 }
640 close(pip[1]);
641 result->fd = pip[0];
642 result->jp = jp;
643 }
644out:
645 popstackmark(&smark);
0d5aaed6 646 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n",
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MD
647 result->fd, result->buf, result->nleft, result->jp));
648}
649
99512ac4
PA
650/*
651 * Check if a builtin can safely be executed in the same process,
652 * even though it should be in a subshell (command substitution).
653 * Note that jobid, jobs, times and trap can show information not
654 * available in a child process; this is deliberate.
655 * The arguments should already have been expanded.
656 */
657static int
658safe_builtin(int idx, int argc, char **argv)
659{
660 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD ||
661 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD ||
662 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD ||
663 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD ||
664 idx == TYPECMD)
665 return (1);
666 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD ||
667 idx == UMASKCMD)
668 return (argc <= 1 || (argc == 2 && argv[1][0] == '-'));
669 if (idx == SETCMD)
670 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' ||
671 argv[1][0] == '+') && argv[1][1] == 'o' &&
672 argv[1][2] == '\0'));
673 return (0);
674}
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MD
675
676/*
677 * Execute a simple command.
99512ac4 678 * Note: This may or may not return if (flags & EV_EXIT).
984263bc
MD
679 */
680
99512ac4 681static void
f2aa3fa5 682evalcommand(union node *cmd, int flgs, struct backcmd *backcmd)
984263bc
MD
683{
684 struct stackmark smark;
685 union node *argp;
686 struct arglist arglist;
687 struct arglist varlist;
f2aa3fa5
PA
688 volatile int flags = flgs;
689 char **volatile argv;
690 volatile int argc;
984263bc
MD
691 char **envp;
692 int varflag;
693 struct strlist *sp;
694 int mode;
695 int pip[2];
696 struct cmdentry cmdentry;
99512ac4 697 struct job *volatile jp;
984263bc 698 struct jmploc jmploc;
99512ac4
PA
699 struct jmploc *savehandler;
700 const char *savecmdname;
701 struct shparam saveparam;
702 struct localvar *savelocalvars;
703 struct parsefile *savetopfile;
984263bc 704 volatile int e;
f2aa3fa5 705 char *volatile lastarg;
984263bc 706 int realstatus;
f2aa3fa5 707 volatile int do_clearcmdentry;
99512ac4 708 const char *path = pathval();
984263bc
MD
709
710 /* First expand the arguments. */
0d5aaed6 711 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags));
984263bc
MD
712 setstackmark(&smark);
713 arglist.lastp = &arglist.list;
714 varlist.lastp = &varlist.list;
715 varflag = 1;
99512ac4 716 jp = NULL;
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MD
717 do_clearcmdentry = 0;
718 oexitstatus = exitstatus;
719 exitstatus = 0;
720 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
088f2cdc
PA
721 if (varflag && isassignment(argp->narg.text)) {
722 expandarg(argp, &varlist, EXP_VARTILDE);
723 continue;
984263bc
MD
724 }
725 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
726 varflag = 0;
727 }
728 *arglist.lastp = NULL;
729 *varlist.lastp = NULL;
730 expredir(cmd->ncmd.redirect);
731 argc = 0;
732 for (sp = arglist.list ; sp ; sp = sp->next)
733 argc++;
99512ac4
PA
734 /* Add one slot at the beginning for tryexec(). */
735 argv = stalloc(sizeof (char *) * (argc + 2));
736 argv++;
984263bc
MD
737
738 for (sp = arglist.list ; sp ; sp = sp->next) {
739 TRACE(("evalcommand arg: %s\n", sp->text));
740 *argv++ = sp->text;
741 }
742 *argv = NULL;
743 lastarg = NULL;
744 if (iflag && funcnest == 0 && argc > 0)
745 lastarg = argv[-1];
746 argv -= argc;
747
748 /* Print the command if xflag is set. */
749 if (xflag) {
0d5aaed6 750 char sep = 0;
99512ac4 751 const char *p;
0d5aaed6 752 out2str(ps4val());
984263bc 753 for (sp = varlist.list ; sp ; sp = sp->next) {
0d5aaed6 754 if (sep != 0)
99512ac4
PA
755 out2c(' ');
756 p = strchr(sp->text, '=');
757 if (p != NULL) {
758 p++;
759 outbin(sp->text, p - sp->text, out2);
760 out2qstr(p);
761 } else
762 out2qstr(sp->text);
0d5aaed6 763 sep = ' ';
984263bc
MD
764 }
765 for (sp = arglist.list ; sp ; sp = sp->next) {
0d5aaed6 766 if (sep != 0)
99512ac4
PA
767 out2c(' ');
768 /* Disambiguate command looking like assignment. */
769 if (sp == arglist.list &&
770 strchr(sp->text, '=') != NULL &&
771 strchr(sp->text, '\'') == NULL) {
772 out2c('\'');
773 out2str(sp->text);
774 out2c('\'');
775 } else
776 out2qstr(sp->text);
0d5aaed6 777 sep = ' ';
984263bc 778 }
99512ac4 779 out2c('\n');
984263bc
MD
780 flushout(&errout);
781 }
782
783 /* Now locate the command. */
784 if (argc == 0) {
0d5aaed6 785 /* Variable assignment(s) without command */
984263bc
MD
786 cmdentry.cmdtype = CMDBUILTIN;
787 cmdentry.u.index = BLTINCMD;
99512ac4 788 cmdentry.special = 0;
984263bc
MD
789 } else {
790 static const char PATH[] = "PATH=";
99512ac4 791 int cmd_flags = 0, bltinonly = 0;
984263bc
MD
792
793 /*
794 * Modify the command lookup path, if a PATH= assignment
795 * is present
796 */
797 for (sp = varlist.list ; sp ; sp = sp->next)
798 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) {
799 path = sp->text + sizeof(PATH) - 1;
0d5aaed6 800 /*
984263bc
MD
801 * On `PATH=... command`, we need to make
802 * sure that the command isn't using the
803 * non-updated hash table of the outer PATH
0d5aaed6 804 * setting and we need to make sure that
984263bc
MD
805 * the hash table isn't filled with items
806 * from the temporary setting.
807 *
0d5aaed6 808 * It would be better to forbit using and
984263bc
MD
809 * updating the table while this command
810 * runs, by the command finding mechanism
811 * is heavily integrated with hash handling,
812 * so we just delete the hash before and after
813 * the command runs. Partly deleting like
814 * changepatch() does doesn't seem worth the
815 * bookinging effort, since most such runs add
0d5aaed6 816 * directories in front of the new PATH.
984263bc 817 */
99512ac4 818 clearcmdentry();
984263bc
MD
819 do_clearcmdentry = 1;
820 }
821
99512ac4
PA
822 for (;;) {
823 if (bltinonly) {
824 cmdentry.u.index = find_builtin(*argv, &cmdentry.special);
825 if (cmdentry.u.index < 0) {
826 cmdentry.u.index = BLTINCMD;
827 argv--;
828 argc++;
984263bc 829 break;
984263bc 830 }
99512ac4
PA
831 } else
832 find_command(argv[0], &cmdentry, cmd_flags, path);
833 /* implement the bltin and command builtins here */
834 if (cmdentry.cmdtype != CMDBUILTIN)
835 break;
836 if (cmdentry.u.index == BLTINCMD) {
837 if (argc == 1)
984263bc 838 break;
99512ac4
PA
839 argv++;
840 argc--;
841 bltinonly = 1;
842 } else if (cmdentry.u.index == COMMANDCMD) {
843 if (argc == 1)
844 break;
845 if (!strcmp(argv[1], "-p")) {
846 if (argc == 2)
847 break;
848 if (argv[2][0] == '-') {
849 if (strcmp(argv[2], "--"))
850 break;
851 if (argc == 3)
852 break;
853 argv += 3;
854 argc -= 3;
855 } else {
856 argv += 2;
857 argc -= 2;
858 }
859 path = _PATH_STDPATH;
860 clearcmdentry();
861 do_clearcmdentry = 1;
862 } else if (!strcmp(argv[1], "--")) {
863 if (argc == 2)
864 break;
865 argv += 2;
866 argc -= 2;
867 } else if (argv[1][0] == '-')
868 break;
869 else {
870 argv++;
871 argc--;
872 }
873 cmd_flags |= DO_NOFUNC;
874 bltinonly = 0;
875 } else
876 break;
984263bc 877 }
99512ac4
PA
878 /*
879 * Special builtins lose their special properties when
880 * called via 'command'.
881 */
882 if (cmd_flags & DO_NOFUNC)
883 cmdentry.special = 0;
984263bc
MD
884 }
885
886 /* Fork off a child process if necessary. */
887 if (cmd->ncmd.backgnd
99512ac4
PA
888 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
889 && ((flags & EV_EXIT) == 0 || have_traps()))
984263bc 890 || ((flags & EV_BACKCMD) != 0
99512ac4
PA
891 && (cmdentry.cmdtype != CMDBUILTIN ||
892 !safe_builtin(cmdentry.u.index, argc, argv)))) {
984263bc
MD
893 jp = makejob(cmd, 1);
894 mode = cmd->ncmd.backgnd;
895 if (flags & EV_BACKCMD) {
896 mode = FORK_NOJOB;
897 if (pipe(pip) < 0)
898 error("Pipe call failed: %s", strerror(errno));
899 }
900 if (forkshell(jp, cmd, mode) != 0)
901 goto parent; /* at end of routine */
902 if (flags & EV_BACKCMD) {
903 FORCEINTON;
904 close(pip[0]);
905 if (pip[1] != 1) {
0d5aaed6 906 dup2(pip[1], 1);
984263bc
MD
907 close(pip[1]);
908 }
909 }
910 flags |= EV_EXIT;
911 }
912
913 /* This is the child process if a fork occurred. */
914 /* Execute the command. */
915 if (cmdentry.cmdtype == CMDFUNCTION) {
916#ifdef DEBUG
917 trputs("Shell function: "); trargs(argv);
918#endif
984263bc
MD
919 saveparam = shellparam;
920 shellparam.malloc = 0;
921 shellparam.reset = 1;
922 shellparam.nparam = argc - 1;
923 shellparam.p = argv + 1;
924 shellparam.optnext = NULL;
925 INTOFF;
926 savelocalvars = localvars;
927 localvars = NULL;
99512ac4
PA
928 reffunc(cmdentry.u.func);
929 savehandler = handler;
984263bc 930 if (setjmp(jmploc.loc)) {
99512ac4
PA
931 freeparam(&shellparam);
932 shellparam = saveparam;
2b23d27f 933 popredir();
99512ac4 934 unreffunc(cmdentry.u.func);
984263bc
MD
935 poplocalvars();
936 localvars = savelocalvars;
99512ac4 937 funcnest--;
984263bc
MD
938 handler = savehandler;
939 longjmp(handler->loc, 1);
940 }
984263bc 941 handler = &jmploc;
99512ac4
PA
942 funcnest++;
943 redirect(cmd->ncmd.redirect, REDIR_PUSH);
944 INTON;
984263bc
MD
945 for (sp = varlist.list ; sp ; sp = sp->next)
946 mklocal(sp->text);
99512ac4 947 exitstatus = oexitstatus;
2b23d27f
PA
948 evaltree(getfuncnode(cmdentry.u.func),
949 flags & (EV_TESTED | EV_EXIT));
984263bc 950 INTOFF;
99512ac4 951 unreffunc(cmdentry.u.func);
984263bc
MD
952 poplocalvars();
953 localvars = savelocalvars;
954 freeparam(&shellparam);
955 shellparam = saveparam;
956 handler = savehandler;
99512ac4 957 funcnest--;
984263bc
MD
958 popredir();
959 INTON;
960 if (evalskip == SKIPFUNC) {
961 evalskip = 0;
962 skipcount = 0;
963 }
99512ac4 964 if (jp)
984263bc
MD
965 exitshell(exitstatus);
966 } else if (cmdentry.cmdtype == CMDBUILTIN) {
967#ifdef DEBUG
968 trputs("builtin command: "); trargs(argv);
969#endif
970 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH;
971 if (flags == EV_BACKCMD) {
972 memout.nleft = 0;
973 memout.nextc = memout.buf;
974 memout.bufsize = 64;
975 mode |= REDIR_BACKQ;
99512ac4 976 cmdentry.special = 0;
984263bc 977 }
984263bc 978 savecmdname = commandname;
99512ac4 979 savetopfile = getcurrentfile();
984263bc
MD
980 cmdenviron = varlist.list;
981 e = -1;
99512ac4 982 savehandler = handler;
984263bc
MD
983 if (setjmp(jmploc.loc)) {
984 e = exception;
2b23d27f
PA
985 if (e == EXINT)
986 exitstatus = SIGINT+128;
987 else if (e != EXEXIT)
988 exitstatus = 2;
984263bc
MD
989 goto cmddone;
990 }
984263bc 991 handler = &jmploc;
0d5aaed6 992 redirect(cmd->ncmd.redirect, mode);
99512ac4
PA
993 /*
994 * If there is no command word, redirection errors should
995 * not be fatal but assignment errors should.
996 */
997 if (argc == 0 && !(flags & EV_BACKCMD))
998 cmdentry.special = 1;
999 listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET);
1000 if (argc > 0)
1001 bltinsetlocale();
984263bc
MD
1002 commandname = argv[0];
1003 argptr = argv + 1;
99512ac4
PA
1004 nextopt_optptr = NULL; /* initialize nextopt */
1005 builtin_flags = flags;
984263bc
MD
1006 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
1007 flushall();
1008cmddone:
99512ac4
PA
1009 if (argc > 0)
1010 bltinunsetlocale();
984263bc
MD
1011 cmdenviron = NULL;
1012 out1 = &output;
1013 out2 = &errout;
1014 freestdout();
984263bc 1015 handler = savehandler;
99512ac4
PA
1016 commandname = savecmdname;
1017 if (jp)
1018 exitshell(exitstatus);
984263bc
MD
1019 if (flags == EV_BACKCMD) {
1020 backcmd->buf = memout.buf;
1021 backcmd->nleft = memout.nextc - memout.buf;
1022 memout.buf = NULL;
1023 }
2b23d27f 1024 if (cmdentry.u.index != EXECCMD)
99512ac4
PA
1025 popredir();
1026 if (e != -1) {
1027 if ((e != EXERROR && e != EXEXEC)
1028 || cmdentry.special)
1029 exraise(e);
1030 popfilesupto(savetopfile);
1031 if (flags != EV_BACKCMD)
1032 FORCEINTON;
1033 }
984263bc
MD
1034 } else {
1035#ifdef DEBUG
1036 trputs("normal command: "); trargs(argv);
1037#endif
984263bc
MD
1038 redirect(cmd->ncmd.redirect, 0);
1039 for (sp = varlist.list ; sp ; sp = sp->next)
1040 setvareq(sp->text, VEXPORT|VSTACK);
1041 envp = environment();
99512ac4 1042 shellexec(argv, envp, path, cmdentry.u.index);
984263bc
MD
1043 /*NOTREACHED*/
1044 }
1045 goto out;
1046
1047parent: /* parent process gets here (if we forked) */
99512ac4 1048 if (mode == FORK_FG) { /* argument to fork */
984263bc
MD
1049 INTOFF;
1050 exitstatus = waitforjob(jp, &realstatus);
1051 INTON;
1052 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) {
1053 evalskip = SKIPBREAK;
1054 skipcount = loopnest;
1055 }
99512ac4 1056 } else if (mode == FORK_NOJOB) {
984263bc
MD
1057 backcmd->fd = pip[0];
1058 close(pip[1]);
1059 backcmd->jp = jp;
5d4731c8
PA
1060 } else
1061 exitstatus = 0;
984263bc
MD
1062
1063out:
1064 if (lastarg)
1065 setvar("_", lastarg, 0);
1066 if (do_clearcmdentry)
99512ac4 1067 clearcmdentry();
984263bc
MD
1068 popstackmark(&smark);
1069}
1070
1071
1072
1073/*
1074 * Search for a command. This is called before we fork so that the
1075 * location of the command will be available in the parent as well as
1076 * the child. The check for "goodname" is an overly conservative
1077 * check that the name will not be subject to expansion.
1078 */
1079
99512ac4 1080static void
984263bc
MD
1081prehash(union node *n)
1082{
1083 struct cmdentry entry;
1084
0d5aaed6 1085 if (n && n->type == NCMD && n->ncmd.args)
984263bc
MD
1086 if (goodname(n->ncmd.args->narg.text))
1087 find_command(n->ncmd.args->narg.text, &entry, 0,
1088 pathval());
1089}
1090
1091
1092
1093/*
1094 * Builtin commands. Builtin commands whose functions are closely
1095 * tied to evaluation are implemented here.
1096 */
1097
1098/*
99512ac4
PA
1099 * No command given, a bltin command with no arguments, or a bltin command
1100 * with an invalid name.
984263bc
MD
1101 */
1102
1103int
99512ac4 1104bltincmd(int argc, char **argv)
984263bc 1105{
99512ac4
PA
1106 if (argc > 1) {
1107 out2fmt_flush("%s: not found\n", argv[1]);
1108 return 127;
1109 }
984263bc
MD
1110 /*
1111 * Preserve exitstatus of a previous possible redirection
1112 * as POSIX mandates
1113 */
1114 return exitstatus;
1115}
1116
1117
1118/*
1119 * Handle break and continue commands. Break, continue, and return are
1120 * all handled by setting the evalskip flag. The evaluation routines
1121 * above all check this flag, and if it is set they start skipping
1122 * commands rather than executing them. The variable skipcount is
1123 * the number of loops to break/continue, or the number of function
1124 * levels to return. (The latter is always 1.) It should probably
1125 * be an error to break out of more loops than exist, but it isn't
1126 * in the standard shell so we don't make it one here.
1127 */
1128
1129int
1130breakcmd(int argc, char **argv)
1131{
1132 int n = argc > 1 ? number(argv[1]) : 1;
1133
1134 if (n > loopnest)
1135 n = loopnest;
1136 if (n > 0) {
1137 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1138 skipcount = n;
1139 }
1140 return 0;
1141}
1142
1143/*
1144 * The `command' command.
1145 */
1146int
1147commandcmd(int argc, char **argv)
1148{
99512ac4 1149 const char *path;
984263bc 1150 int ch;
0d5aaed6 1151 int cmd = -1;
984263bc 1152
99512ac4 1153 path = bltinlookup("PATH", 1);
984263bc
MD
1154
1155 optind = optreset = 1;
1156 opterr = 0;
0d5aaed6 1157 while ((ch = getopt(argc, argv, "pvV")) != -1) {
984263bc
MD
1158 switch (ch) {
1159 case 'p':
99512ac4 1160 path = _PATH_STDPATH;
984263bc 1161 break;
0d5aaed6
PA
1162 case 'v':
1163 cmd = TYPECMD_SMALLV;
1164 break;
1165 case 'V':
1166 cmd = TYPECMD_BIGV;
1167 break;
984263bc
MD
1168 case '?':
1169 default:
1170 error("unknown option: -%c", optopt);
1171 }
1172 }
1173 argc -= optind;
1174 argv += optind;
1175
0d5aaed6
PA
1176 if (cmd != -1) {
1177 if (argc != 1)
1178 error("wrong number of arguments");
99512ac4 1179 return typecmd_impl(2, argv - 1, cmd, path);
984263bc 1180 }
99512ac4
PA
1181 if (argc != 0)
1182 error("commandcmd bad call");
984263bc
MD
1183
1184 /*
1185 * Do nothing successfully if no command was specified;
1186 * ksh also does this.
1187 */
99512ac4 1188 return(0);
984263bc
MD
1189}
1190
1191
1192/*
1193 * The return command.
1194 */
1195
1196int
1197returncmd(int argc, char **argv)
1198{
1199 int ret = argc > 1 ? number(argv[1]) : oexitstatus;
1200
1201 if (funcnest) {
1202 evalskip = SKIPFUNC;
1203 skipcount = 1;
1204 } else {
1205 /* skip the rest of the file */
1206 evalskip = SKIPFILE;
1207 skipcount = 1;
1208 }
1209 return ret;
1210}
1211
1212
1213int
1214falsecmd(int argc __unused, char **argv __unused)
1215{
1216 return 1;
1217}
1218
1219
1220int
1221truecmd(int argc __unused, char **argv __unused)
1222{
1223 return 0;
1224}
1225
1226
1227int
1228execcmd(int argc, char **argv)
1229{
99512ac4
PA
1230 /*
1231 * Because we have historically not supported any options,
1232 * only treat "--" specially.
1233 */
1234 if (argc > 1 && strcmp(argv[1], "--") == 0)
1235 argc--, argv++;
984263bc
MD
1236 if (argc > 1) {
1237 struct strlist *sp;
1238
1239 iflag = 0; /* exit on error */
1240 mflag = 0;
1241 optschanged();
1242 for (sp = cmdenviron; sp ; sp = sp->next)
1243 setvareq(sp->text, VEXPORT|VSTACK);
1244 shellexec(argv + 1, environment(), pathval(), 0);
1245
1246 }
1247 return 0;
1248}
0d5aaed6
PA
1249
1250
1251int
1252timescmd(int argc __unused, char **argv __unused)
1253{
1254 struct rusage ru;
1255 long shumins, shsmins, chumins, chsmins;
1256 double shusecs, shssecs, chusecs, chssecs;
1257
1258 if (getrusage(RUSAGE_SELF, &ru) < 0)
1259 return 1;
1260 shumins = ru.ru_utime.tv_sec / 60;
1261 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.;
1262 shsmins = ru.ru_stime.tv_sec / 60;
1263 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.;
1264 if (getrusage(RUSAGE_CHILDREN, &ru) < 0)
1265 return 1;
1266 chumins = ru.ru_utime.tv_sec / 60;
1267 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.;
1268 chsmins = ru.ru_stime.tv_sec / 60;
1269 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.;
1270 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins,
1271 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs);
1272 return 0;
1273}