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 * 4. 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.
19 *
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
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
|
39__FBSDID("$FreeBSD: head/bin/sh/eval.c 268927 2014-07-20 20:29:09Z jilles $");
|
| 39__FBSDID("$FreeBSD: head/bin/sh/eval.c 272575 2014-10-05 21:51:36Z jilles $"); |
40
41#include <paths.h>
42#include <signal.h>
43#include <stdlib.h>
44#include <unistd.h>
45#include <sys/resource.h>
46#include <sys/wait.h> /* For WIFSIGNALED(status) */
47#include <errno.h>
48
49/*
50 * Evaluate a command.
51 */
52
53#include "shell.h"
54#include "nodes.h"
55#include "syntax.h"
56#include "expand.h"
57#include "parser.h"
58#include "jobs.h"
59#include "eval.h"
60#include "builtins.h"
61#include "options.h"
62#include "exec.h"
63#include "redir.h"
64#include "input.h"
65#include "output.h"
66#include "trap.h"
67#include "var.h"
68#include "memalloc.h"
69#include "error.h"
70#include "show.h"
71#include "mystring.h"
72#ifndef NO_HISTORY
73#include "myhistedit.h"
74#endif
75
76
77int evalskip; /* set if we are skipping commands */
78int skipcount; /* number of levels to skip */
79static int loopnest; /* current loop nesting level */
80int funcnest; /* depth of function calls */
81static int builtin_flags; /* evalcommand flags for builtins */
82
83
84char *commandname;
85struct strlist *cmdenviron;
86int exitstatus; /* exit status of last command */
87int oexitstatus; /* saved exit status */
88
89
90static void evalloop(union node *, int);
91static void evalfor(union node *, int);
92static union node *evalcase(union node *);
93static void evalsubshell(union node *, int);
94static void evalredir(union node *, int);
95static void exphere(union node *, struct arglist *);
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 *);
101
102
103/*
104 * Called to reset things after an exception.
105 */
106
107void
108reseteval(void)
109{
110 evalskip = 0;
111 loopnest = 0;
112}
113
114
115/*
116 * The eval command.
117 */
118
119int
120evalcmd(int argc, char **argv)
121{
122 char *p;
123 char *concat;
124 char **ap;
125
126 if (argc > 1) {
127 p = argv[1];
128 if (argc > 2) {
129 STARTSTACKSTR(concat);
130 ap = argv + 2;
131 for (;;) {
132 STPUTS(p, concat);
133 if ((p = *ap++) == NULL)
134 break;
135 STPUTC(' ', concat);
136 }
137 STPUTC('\0', concat);
138 p = grabstackstr(concat);
139 }
140 evalstring(p, builtin_flags);
141 } else
142 exitstatus = 0;
143 return exitstatus;
144}
145
146
147/*
148 * Execute a command or commands contained in a string.
149 */
150
151void
152evalstring(char *s, int flags)
153{
154 union node *n;
155 struct stackmark smark;
156 int flags_exit;
157 int any;
158
159 flags_exit = flags & EV_EXIT;
160 flags &= ~EV_EXIT;
161 any = 0;
162 setstackmark(&smark);
163 setinputstring(s, 1);
164 while ((n = parsecmd(0)) != NEOF) {
165 if (n != NULL && !nflag) {
166 if (flags_exit && preadateof())
167 evaltree(n, flags | EV_EXIT);
168 else
169 evaltree(n, flags);
170 any = 1;
171 }
172 popstackmark(&smark);
173 setstackmark(&smark);
174 }
175 popfile();
176 popstackmark(&smark);
177 if (!any)
178 exitstatus = 0;
179 if (flags_exit)
180 exraise(EXEXIT);
181}
182
183
184/*
185 * Evaluate a parse tree. The value is left in the global variable
186 * exitstatus.
187 */
188
189void
190evaltree(union node *n, int flags)
191{
192 int do_etest;
193 union node *next;
194 struct stackmark smark;
195
196 setstackmark(&smark);
197 do_etest = 0;
198 if (n == NULL) {
199 TRACE(("evaltree(NULL) called\n"));
200 exitstatus = 0;
201 goto out;
202 }
203 do {
204 next = NULL;
205#ifndef NO_HISTORY
206 displayhist = 1; /* show history substitutions done with fc */
207#endif
208 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type));
209 switch (n->type) {
210 case NSEMI:
211 evaltree(n->nbinary.ch1, flags & ~EV_EXIT);
212 if (evalskip)
213 goto out;
214 next = n->nbinary.ch2;
215 break;
216 case NAND:
217 evaltree(n->nbinary.ch1, EV_TESTED);
218 if (evalskip || exitstatus != 0) {
219 goto out;
220 }
221 next = n->nbinary.ch2;
222 break;
223 case NOR:
224 evaltree(n->nbinary.ch1, EV_TESTED);
225 if (evalskip || exitstatus == 0)
226 goto out;
227 next = n->nbinary.ch2;
228 break;
229 case NREDIR:
230 evalredir(n, flags);
231 break;
232 case NSUBSHELL:
233 evalsubshell(n, flags);
234 do_etest = !(flags & EV_TESTED);
235 break;
236 case NBACKGND:
237 evalsubshell(n, flags);
238 break;
239 case NIF: {
240 evaltree(n->nif.test, EV_TESTED);
241 if (evalskip)
242 goto out;
243 if (exitstatus == 0)
244 next = n->nif.ifpart;
245 else if (n->nif.elsepart)
246 next = n->nif.elsepart;
247 else
248 exitstatus = 0;
249 break;
250 }
251 case NWHILE:
252 case NUNTIL:
253 evalloop(n, flags & ~EV_EXIT);
254 break;
255 case NFOR:
256 evalfor(n, flags & ~EV_EXIT);
257 break;
258 case NCASE:
259 next = evalcase(n);
260 break;
261 case NCLIST:
262 next = n->nclist.body;
263 break;
264 case NCLISTFALLTHRU:
265 if (n->nclist.body) {
266 evaltree(n->nclist.body, flags & ~EV_EXIT);
267 if (evalskip)
268 goto out;
269 }
270 next = n->nclist.next;
271 break;
272 case NDEFUN:
273 defun(n->narg.text, n->narg.next);
274 exitstatus = 0;
275 break;
276 case NNOT:
277 evaltree(n->nnot.com, EV_TESTED);
278 if (evalskip)
279 goto out;
280 exitstatus = !exitstatus;
281 break;
282
283 case NPIPE:
284 evalpipe(n);
285 do_etest = !(flags & EV_TESTED);
286 break;
287 case NCMD:
288 evalcommand(n, flags, (struct backcmd *)NULL);
289 do_etest = !(flags & EV_TESTED);
290 break;
291 default:
292 out1fmt("Node type = %d\n", n->type);
293 flushout(&output);
294 break;
295 }
296 n = next;
297 popstackmark(&smark);
298 setstackmark(&smark);
299 } while (n != NULL);
300out:
301 popstackmark(&smark);
302 if (pendingsig)
303 dotrap();
304 if (eflag && exitstatus != 0 && do_etest)
305 exitshell(exitstatus);
306 if (flags & EV_EXIT)
307 exraise(EXEXIT);
308}
309
310
311static void
312evalloop(union node *n, int flags)
313{
314 int status;
315
316 loopnest++;
317 status = 0;
318 for (;;) {
|
319 evaltree(n->nbinary.ch1, EV_TESTED);
|
319 if (!evalskip)
320 evaltree(n->nbinary.ch1, EV_TESTED); |
321 if (evalskip) {
|
321skipping: if (evalskip == SKIPCONT && --skipcount <= 0) {
|
| 322 if (evalskip == SKIPCONT && --skipcount <= 0) { |
323 evalskip = 0;
324 continue;
325 }
326 if (evalskip == SKIPBREAK && --skipcount <= 0)
327 evalskip = 0;
328 if (evalskip == SKIPRETURN)
329 status = exitstatus;
330 break;
331 }
332 if (n->type == NWHILE) {
333 if (exitstatus != 0)
334 break;
335 } else {
336 if (exitstatus == 0)
337 break;
338 }
339 evaltree(n->nbinary.ch2, flags);
340 status = exitstatus;
|
340 if (evalskip)
341 goto skipping;
|
341 }
342 loopnest--;
343 exitstatus = status;
344}
345
346
347
348static void
349evalfor(union node *n, int flags)
350{
351 struct arglist arglist;
352 union node *argp;
353 struct strlist *sp;
354 int status;
355
356 arglist.lastp = &arglist.list;
357 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
358 oexitstatus = exitstatus;
359 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
360 }
361 *arglist.lastp = NULL;
362
363 loopnest++;
364 status = 0;
365 for (sp = arglist.list ; sp ; sp = sp->next) {
366 setvar(n->nfor.var, sp->text, 0);
367 evaltree(n->nfor.body, flags);
368 status = exitstatus;
369 if (evalskip) {
370 if (evalskip == SKIPCONT && --skipcount <= 0) {
371 evalskip = 0;
372 continue;
373 }
374 if (evalskip == SKIPBREAK && --skipcount <= 0)
375 evalskip = 0;
376 break;
377 }
378 }
379 loopnest--;
380 exitstatus = status;
381}
382
383
384/*
385 * Evaluate a case statement, returning the selected tree.
386 *
387 * The exit status needs care to get right.
388 */
389
390static union node *
391evalcase(union node *n)
392{
393 union node *cp;
394 union node *patp;
395 struct arglist arglist;
396
397 arglist.lastp = &arglist.list;
398 oexitstatus = exitstatus;
399 expandarg(n->ncase.expr, &arglist, EXP_TILDE);
400 for (cp = n->ncase.cases ; cp ; cp = cp->nclist.next) {
401 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
402 if (casematch(patp, arglist.list->text)) {
403 while (cp->nclist.next &&
404 cp->type == NCLISTFALLTHRU &&
405 cp->nclist.body == NULL)
406 cp = cp->nclist.next;
407 if (cp->nclist.next &&
408 cp->type == NCLISTFALLTHRU)
409 return (cp);
410 if (cp->nclist.body == NULL)
411 exitstatus = 0;
412 return (cp->nclist.body);
413 }
414 }
415 }
416 exitstatus = 0;
417 return (NULL);
418}
419
420
421
422/*
423 * Kick off a subshell to evaluate a tree.
424 */
425
426static void
427evalsubshell(union node *n, int flags)
428{
429 struct job *jp;
430 int backgnd = (n->type == NBACKGND);
431
432 oexitstatus = exitstatus;
433 expredir(n->nredir.redirect);
434 if ((!backgnd && flags & EV_EXIT && !have_traps()) ||
435 forkshell(jp = makejob(n, 1), n, backgnd) == 0) {
436 if (backgnd)
437 flags &=~ EV_TESTED;
438 redirect(n->nredir.redirect, 0);
439 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */
440 } else if (! backgnd) {
441 INTOFF;
442 exitstatus = waitforjob(jp, (int *)NULL);
443 INTON;
444 } else
445 exitstatus = 0;
446}
447
448
449/*
450 * Evaluate a redirected compound command.
451 */
452
453static void
454evalredir(union node *n, int flags)
455{
456 struct jmploc jmploc;
457 struct jmploc *savehandler;
458 volatile int in_redirect = 1;
459
460 oexitstatus = exitstatus;
461 expredir(n->nredir.redirect);
462 savehandler = handler;
463 if (setjmp(jmploc.loc)) {
464 int e;
465
466 handler = savehandler;
467 e = exception;
468 popredir();
469 if (e == EXERROR || e == EXEXEC) {
470 if (in_redirect) {
471 exitstatus = 2;
472 return;
473 }
474 }
475 longjmp(handler->loc, 1);
476 } else {
477 INTOFF;
478 handler = &jmploc;
479 redirect(n->nredir.redirect, REDIR_PUSH);
480 in_redirect = 0;
481 INTON;
482 evaltree(n->nredir.n, flags);
483 }
484 INTOFF;
485 handler = savehandler;
486 popredir();
487 INTON;
488}
489
490
491static void
492exphere(union node *redir, struct arglist *fn)
493{
494 struct jmploc jmploc;
495 struct jmploc *savehandler;
496 struct localvar *savelocalvars;
497 int need_longjmp = 0;
498
499 redir->nhere.expdoc = nullstr;
500 savelocalvars = localvars;
501 localvars = NULL;
502 forcelocal++;
503 savehandler = handler;
504 if (setjmp(jmploc.loc))
505 need_longjmp = exception != EXERROR && exception != EXEXEC;
506 else {
507 handler = &jmploc;
508 expandarg(redir->nhere.doc, fn, 0);
509 redir->nhere.expdoc = fn->list->text;
510 INTOFF;
511 }
512 handler = savehandler;
513 forcelocal--;
514 poplocalvars();
515 localvars = savelocalvars;
516 if (need_longjmp)
517 longjmp(handler->loc, 1);
518 INTON;
519}
520
521
522/*
523 * Compute the names of the files in a redirection list.
524 */
525
526static void
527expredir(union node *n)
528{
529 union node *redir;
530
531 for (redir = n ; redir ; redir = redir->nfile.next) {
532 struct arglist fn;
533 fn.lastp = &fn.list;
534 switch (redir->type) {
535 case NFROM:
536 case NTO:
537 case NFROMTO:
538 case NAPPEND:
539 case NCLOBBER:
540 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
541 redir->nfile.expfname = fn.list->text;
542 break;
543 case NFROMFD:
544 case NTOFD:
545 if (redir->ndup.vname) {
546 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
547 fixredir(redir, fn.list->text, 1);
548 }
549 break;
550 case NXHERE:
551 exphere(redir, &fn);
552 break;
553 }
554 }
555}
556
557
558
559/*
560 * Evaluate a pipeline. All the processes in the pipeline are children
561 * of the process creating the pipeline. (This differs from some versions
562 * of the shell, which make the last process in a pipeline the parent
563 * of all the rest.)
564 */
565
566static void
567evalpipe(union node *n)
568{
569 struct job *jp;
570 struct nodelist *lp;
571 int pipelen;
572 int prevfd;
573 int pip[2];
574
575 TRACE(("evalpipe(%p) called\n", (void *)n));
576 pipelen = 0;
577 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
578 pipelen++;
579 INTOFF;
580 jp = makejob(n, pipelen);
581 prevfd = -1;
582 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
583 prehash(lp->n);
584 pip[1] = -1;
585 if (lp->next) {
586 if (pipe(pip) < 0) {
587 if (prevfd >= 0)
588 close(prevfd);
589 error("Pipe call failed: %s", strerror(errno));
590 }
591 }
592 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
593 INTON;
594 if (prevfd > 0) {
595 dup2(prevfd, 0);
596 close(prevfd);
597 }
598 if (pip[1] >= 0) {
599 if (!(prevfd >= 0 && pip[0] == 0))
600 close(pip[0]);
601 if (pip[1] != 1) {
602 dup2(pip[1], 1);
603 close(pip[1]);
604 }
605 }
606 evaltree(lp->n, EV_EXIT);
607 }
608 if (prevfd >= 0)
609 close(prevfd);
610 prevfd = pip[0];
611 if (pip[1] != -1)
612 close(pip[1]);
613 }
614 INTON;
615 if (n->npipe.backgnd == 0) {
616 INTOFF;
617 exitstatus = waitforjob(jp, (int *)NULL);
618 TRACE(("evalpipe: job done exit status %d\n", exitstatus));
619 INTON;
620 } else
621 exitstatus = 0;
622}
623
624
625
626static int
627is_valid_fast_cmdsubst(union node *n)
628{
629
630 return (n->type == NCMD);
631}
632
633/*
634 * Execute a command inside back quotes. If it's a builtin command, we
635 * want to save its output in a block obtained from malloc. Otherwise
636 * we fork off a subprocess and get the output of the command via a pipe.
637 * Should be called with interrupts off.
638 */
639
640void
641evalbackcmd(union node *n, struct backcmd *result)
642{
643 int pip[2];
644 struct job *jp;
645 struct stackmark smark;
646 struct jmploc jmploc;
647 struct jmploc *savehandler;
648 struct localvar *savelocalvars;
649
|
651 setstackmark(&smark);
|
650 result->fd = -1;
651 result->buf = NULL;
652 result->nleft = 0;
653 result->jp = NULL;
654 if (n == NULL) {
655 exitstatus = 0;
|
658 goto out;
|
| 656 return; |
657 }
|
| 658 setstackmark(&smark); |
659 exitstatus = oexitstatus;
660 if (is_valid_fast_cmdsubst(n)) {
661 savelocalvars = localvars;
662 localvars = NULL;
663 forcelocal++;
664 savehandler = handler;
665 if (setjmp(jmploc.loc)) {
666 if (exception == EXERROR || exception == EXEXEC)
667 exitstatus = 2;
668 else if (exception != 0) {
669 handler = savehandler;
670 forcelocal--;
671 poplocalvars();
672 localvars = savelocalvars;
673 longjmp(handler->loc, 1);
674 }
675 } else {
676 handler = &jmploc;
677 evalcommand(n, EV_BACKCMD, result);
678 }
679 handler = savehandler;
680 forcelocal--;
681 poplocalvars();
682 localvars = savelocalvars;
683 } else {
684 if (pipe(pip) < 0)
685 error("Pipe call failed: %s", strerror(errno));
686 jp = makejob(n, 1);
687 if (forkshell(jp, n, FORK_NOJOB) == 0) {
688 FORCEINTON;
689 close(pip[0]);
690 if (pip[1] != 1) {
691 dup2(pip[1], 1);
692 close(pip[1]);
693 }
694 evaltree(n, EV_EXIT);
695 }
696 close(pip[1]);
697 result->fd = pip[0];
698 result->jp = jp;
699 }
|
701out:
|
700 popstackmark(&smark);
701 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n",
702 result->fd, result->buf, result->nleft, result->jp));
703}
704
705static int
706mustexpandto(const char *argtext, const char *mask)
707{
708 for (;;) {
709 if (*argtext == CTLQUOTEMARK || *argtext == CTLQUOTEEND) {
710 argtext++;
711 continue;
712 }
713 if (*argtext == CTLESC)
714 argtext++;
715 else if (BASESYNTAX[(int)*argtext] == CCTL)
716 return (0);
717 if (*argtext != *mask)
718 return (0);
719 if (*argtext == '\0')
720 return (1);
721 argtext++;
722 mask++;
723 }
724}
725
726static int
727isdeclarationcmd(struct narg *arg)
728{
729 int have_command = 0;
730
731 if (arg == NULL)
732 return (0);
733 while (mustexpandto(arg->text, "command")) {
734 have_command = 1;
735 arg = &arg->next->narg;
736 if (arg == NULL)
737 return (0);
738 /*
739 * To also allow "command -p" and "command --" as part of
740 * a declaration command, add code here.
741 * We do not do this, as ksh does not do it either and it
742 * is not required by POSIX.
743 */
744 }
745 return (mustexpandto(arg->text, "export") ||
746 mustexpandto(arg->text, "readonly") ||
747 (mustexpandto(arg->text, "local") &&
748 (have_command || !isfunc("local"))));
749}
750
751static void
752xtracecommand(struct arglist *varlist, struct arglist *arglist)
753{
754 struct strlist *sp;
755 char sep = 0;
756 const char *p, *ps4;
757
758 ps4 = expandstr(ps4val());
759 out2str(ps4 != NULL ? ps4 : ps4val());
760 for (sp = varlist->list ; sp ; sp = sp->next) {
761 if (sep != 0)
762 out2c(' ');
763 p = strchr(sp->text, '=');
764 if (p != NULL) {
765 p++;
766 outbin(sp->text, p - sp->text, out2);
767 out2qstr(p);
768 } else
769 out2qstr(sp->text);
770 sep = ' ';
771 }
772 for (sp = arglist->list ; sp ; sp = sp->next) {
773 if (sep != 0)
774 out2c(' ');
775 /* Disambiguate command looking like assignment. */
776 if (sp == arglist->list &&
777 strchr(sp->text, '=') != NULL &&
778 strchr(sp->text, '\'') == NULL) {
779 out2c('\'');
780 out2str(sp->text);
781 out2c('\'');
782 } else
783 out2qstr(sp->text);
784 sep = ' ';
785 }
786 out2c('\n');
787 flushout(&errout);
788}
789
790/*
791 * Check if a builtin can safely be executed in the same process,
792 * even though it should be in a subshell (command substitution).
793 * Note that jobid, jobs, times and trap can show information not
794 * available in a child process; this is deliberate.
795 * The arguments should already have been expanded.
796 */
797static int
798safe_builtin(int idx, int argc, char **argv)
799{
800 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD ||
801 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD ||
802 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD ||
803 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD ||
804 idx == TYPECMD)
805 return (1);
806 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD ||
807 idx == UMASKCMD)
808 return (argc <= 1 || (argc == 2 && argv[1][0] == '-'));
809 if (idx == SETCMD)
810 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' ||
811 argv[1][0] == '+') && argv[1][1] == 'o' &&
812 argv[1][2] == '\0'));
813 return (0);
814}
815
816/*
817 * Execute a simple command.
818 * Note: This may or may not return if (flags & EV_EXIT).
819 */
820
821static void
822evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
823{
824 union node *argp;
825 struct arglist arglist;
826 struct arglist varlist;
827 char **argv;
828 int argc;
829 char **envp;
830 int varflag;
831 struct strlist *sp;
832 int mode;
833 int pip[2];
834 struct cmdentry cmdentry;
835 struct job *jp;
836 struct jmploc jmploc;
837 struct jmploc *savehandler;
838 char *savecmdname;
839 struct shparam saveparam;
840 struct localvar *savelocalvars;
841 struct parsefile *savetopfile;
842 volatile int e;
843 char *lastarg;
844 int realstatus;
845 int do_clearcmdentry;
846 const char *path = pathval();
847
848 /* First expand the arguments. */
849 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags));
850 arglist.lastp = &arglist.list;
851 varlist.lastp = &varlist.list;
852 varflag = 1;
853 jp = NULL;
854 do_clearcmdentry = 0;
855 oexitstatus = exitstatus;
856 exitstatus = 0;
857 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
858 if (varflag && isassignment(argp->narg.text)) {
859 expandarg(argp, varflag == 1 ? &varlist : &arglist,
860 EXP_VARTILDE);
861 continue;
862 } else if (varflag == 1)
863 varflag = isdeclarationcmd(&argp->narg) ? 2 : 0;
864 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
865 }
866 *arglist.lastp = NULL;
867 *varlist.lastp = NULL;
868 expredir(cmd->ncmd.redirect);
869 argc = 0;
870 for (sp = arglist.list ; sp ; sp = sp->next)
871 argc++;
872 /* Add one slot at the beginning for tryexec(). */
873 argv = stalloc(sizeof (char *) * (argc + 2));
874 argv++;
875
876 for (sp = arglist.list ; sp ; sp = sp->next) {
877 TRACE(("evalcommand arg: %s\n", sp->text));
878 *argv++ = sp->text;
879 }
880 *argv = NULL;
881 lastarg = NULL;
882 if (iflag && funcnest == 0 && argc > 0)
883 lastarg = argv[-1];
884 argv -= argc;
885
886 /* Print the command if xflag is set. */
887 if (xflag)
888 xtracecommand(&varlist, &arglist);
889
890 /* Now locate the command. */
891 if (argc == 0) {
892 /* Variable assignment(s) without command */
893 cmdentry.cmdtype = CMDBUILTIN;
894 cmdentry.u.index = BLTINCMD;
895 cmdentry.special = 0;
896 } else {
897 static const char PATH[] = "PATH=";
898 int cmd_flags = 0, bltinonly = 0;
899
900 /*
901 * Modify the command lookup path, if a PATH= assignment
902 * is present
903 */
904 for (sp = varlist.list ; sp ; sp = sp->next)
905 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) {
906 path = sp->text + sizeof(PATH) - 1;
907 /*
908 * On `PATH=... command`, we need to make
909 * sure that the command isn't using the
910 * non-updated hash table of the outer PATH
911 * setting and we need to make sure that
912 * the hash table isn't filled with items
913 * from the temporary setting.
914 *
915 * It would be better to forbit using and
916 * updating the table while this command
917 * runs, by the command finding mechanism
918 * is heavily integrated with hash handling,
919 * so we just delete the hash before and after
920 * the command runs. Partly deleting like
921 * changepatch() does doesn't seem worth the
922 * bookinging effort, since most such runs add
923 * directories in front of the new PATH.
924 */
925 clearcmdentry();
926 do_clearcmdentry = 1;
927 }
928
929 for (;;) {
930 if (bltinonly) {
931 cmdentry.u.index = find_builtin(*argv, &cmdentry.special);
932 if (cmdentry.u.index < 0) {
933 cmdentry.u.index = BLTINCMD;
934 argv--;
935 argc++;
936 break;
937 }
938 } else
939 find_command(argv[0], &cmdentry, cmd_flags, path);
940 /* implement the bltin and command builtins here */
941 if (cmdentry.cmdtype != CMDBUILTIN)
942 break;
943 if (cmdentry.u.index == BLTINCMD) {
944 if (argc == 1)
945 break;
946 argv++;
947 argc--;
948 bltinonly = 1;
949 } else if (cmdentry.u.index == COMMANDCMD) {
950 if (argc == 1)
951 break;
952 if (!strcmp(argv[1], "-p")) {
953 if (argc == 2)
954 break;
955 if (argv[2][0] == '-') {
956 if (strcmp(argv[2], "--"))
957 break;
958 if (argc == 3)
959 break;
960 argv += 3;
961 argc -= 3;
962 } else {
963 argv += 2;
964 argc -= 2;
965 }
966 path = _PATH_STDPATH;
967 clearcmdentry();
968 do_clearcmdentry = 1;
969 } else if (!strcmp(argv[1], "--")) {
970 if (argc == 2)
971 break;
972 argv += 2;
973 argc -= 2;
974 } else if (argv[1][0] == '-')
975 break;
976 else {
977 argv++;
978 argc--;
979 }
980 cmd_flags |= DO_NOFUNC;
981 bltinonly = 0;
982 } else
983 break;
984 }
985 /*
986 * Special builtins lose their special properties when
987 * called via 'command'.
988 */
989 if (cmd_flags & DO_NOFUNC)
990 cmdentry.special = 0;
991 }
992
993 /* Fork off a child process if necessary. */
994 if (((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
995 && ((flags & EV_EXIT) == 0 || have_traps()))
996 || ((flags & EV_BACKCMD) != 0
997 && (cmdentry.cmdtype != CMDBUILTIN ||
998 !safe_builtin(cmdentry.u.index, argc, argv)))) {
999 jp = makejob(cmd, 1);
1000 mode = FORK_FG;
1001 if (flags & EV_BACKCMD) {
1002 mode = FORK_NOJOB;
1003 if (pipe(pip) < 0)
1004 error("Pipe call failed: %s", strerror(errno));
1005 }
1006 if (cmdentry.cmdtype == CMDNORMAL &&
1007 cmd->ncmd.redirect == NULL &&
1008 varlist.list == NULL &&
1009 (mode == FORK_FG || mode == FORK_NOJOB) &&
1010 !disvforkset() && !iflag && !mflag) {
1011 vforkexecshell(jp, argv, environment(), path,
1012 cmdentry.u.index, flags & EV_BACKCMD ? pip : NULL);
1013 goto parent;
1014 }
1015 if (forkshell(jp, cmd, mode) != 0)
1016 goto parent; /* at end of routine */
1017 if (flags & EV_BACKCMD) {
1018 FORCEINTON;
1019 close(pip[0]);
1020 if (pip[1] != 1) {
1021 dup2(pip[1], 1);
1022 close(pip[1]);
1023 }
1024 flags &= ~EV_BACKCMD;
1025 }
1026 flags |= EV_EXIT;
1027 }
1028
1029 /* This is the child process if a fork occurred. */
1030 /* Execute the command. */
1031 if (cmdentry.cmdtype == CMDFUNCTION) {
1032#ifdef DEBUG
1033 trputs("Shell function: "); trargs(argv);
1034#endif
1035 saveparam = shellparam;
1036 shellparam.malloc = 0;
1037 shellparam.reset = 1;
1038 shellparam.nparam = argc - 1;
1039 shellparam.p = argv + 1;
1040 shellparam.optnext = NULL;
1041 INTOFF;
1042 savelocalvars = localvars;
1043 localvars = NULL;
1044 reffunc(cmdentry.u.func);
1045 savehandler = handler;
1046 if (setjmp(jmploc.loc)) {
1047 freeparam(&shellparam);
1048 shellparam = saveparam;
1049 popredir();
1050 unreffunc(cmdentry.u.func);
1051 poplocalvars();
1052 localvars = savelocalvars;
1053 funcnest--;
1054 handler = savehandler;
1055 longjmp(handler->loc, 1);
1056 }
1057 handler = &jmploc;
1058 funcnest++;
1059 redirect(cmd->ncmd.redirect, REDIR_PUSH);
1060 INTON;
1061 for (sp = varlist.list ; sp ; sp = sp->next)
1062 mklocal(sp->text);
1063 exitstatus = oexitstatus;
1064 evaltree(getfuncnode(cmdentry.u.func),
1065 flags & (EV_TESTED | EV_EXIT));
1066 INTOFF;
1067 unreffunc(cmdentry.u.func);
1068 poplocalvars();
1069 localvars = savelocalvars;
1070 freeparam(&shellparam);
1071 shellparam = saveparam;
1072 handler = savehandler;
1073 funcnest--;
1074 popredir();
1075 INTON;
1076 if (evalskip == SKIPRETURN) {
1077 evalskip = 0;
1078 skipcount = 0;
1079 }
1080 if (jp)
1081 exitshell(exitstatus);
1082 } else if (cmdentry.cmdtype == CMDBUILTIN) {
1083#ifdef DEBUG
1084 trputs("builtin command: "); trargs(argv);
1085#endif
1086 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH;
1087 if (flags == EV_BACKCMD) {
1088 memout.nleft = 0;
1089 memout.nextc = memout.buf;
1090 memout.bufsize = 64;
1091 mode |= REDIR_BACKQ;
1092 }
1093 savecmdname = commandname;
1094 savetopfile = getcurrentfile();
1095 cmdenviron = varlist.list;
1096 e = -1;
1097 savehandler = handler;
1098 if (setjmp(jmploc.loc)) {
1099 e = exception;
1100 if (e == EXINT)
1101 exitstatus = SIGINT+128;
1102 else if (e != EXEXIT)
1103 exitstatus = 2;
1104 goto cmddone;
1105 }
1106 handler = &jmploc;
1107 redirect(cmd->ncmd.redirect, mode);
1108 outclearerror(out1);
1109 /*
1110 * If there is no command word, redirection errors should
1111 * not be fatal but assignment errors should.
1112 */
1113 if (argc == 0)
1114 cmdentry.special = 1;
1115 listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET);
1116 if (argc > 0)
1117 bltinsetlocale();
1118 commandname = argv[0];
1119 argptr = argv + 1;
1120 nextopt_optptr = NULL; /* initialize nextopt */
1121 builtin_flags = flags;
1122 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
1123 flushall();
1124 if (outiserror(out1)) {
1125 warning("write error on stdout");
1126 if (exitstatus == 0 || exitstatus == 1)
1127 exitstatus = 2;
1128 }
1129cmddone:
1130 if (argc > 0)
1131 bltinunsetlocale();
1132 cmdenviron = NULL;
1133 out1 = &output;
1134 out2 = &errout;
1135 freestdout();
1136 handler = savehandler;
1137 commandname = savecmdname;
1138 if (jp)
1139 exitshell(exitstatus);
1140 if (flags == EV_BACKCMD) {
1141 backcmd->buf = memout.buf;
1142 backcmd->nleft = memout.nextc - memout.buf;
1143 memout.buf = NULL;
1144 }
1145 if (cmdentry.u.index != EXECCMD)
1146 popredir();
1147 if (e != -1) {
1148 if ((e != EXERROR && e != EXEXEC)
1149 || cmdentry.special)
1150 exraise(e);
1151 popfilesupto(savetopfile);
1152 if (flags != EV_BACKCMD)
1153 FORCEINTON;
1154 }
1155 } else {
1156#ifdef DEBUG
1157 trputs("normal command: "); trargs(argv);
1158#endif
1159 redirect(cmd->ncmd.redirect, 0);
1160 for (sp = varlist.list ; sp ; sp = sp->next)
1161 setvareq(sp->text, VEXPORT|VSTACK);
1162 envp = environment();
1163 shellexec(argv, envp, path, cmdentry.u.index);
1164 /*NOTREACHED*/
1165 }
1166 goto out;
1167
1168parent: /* parent process gets here (if we forked) */
1169 if (mode == FORK_FG) { /* argument to fork */
1170 INTOFF;
1171 exitstatus = waitforjob(jp, &realstatus);
1172 INTON;
1173 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) {
1174 evalskip = SKIPBREAK;
1175 skipcount = loopnest;
1176 }
1177 } else if (mode == FORK_NOJOB) {
1178 backcmd->fd = pip[0];
1179 close(pip[1]);
1180 backcmd->jp = jp;
1181 }
1182
1183out:
1184 if (lastarg)
1185 setvar("_", lastarg, 0);
1186 if (do_clearcmdentry)
1187 clearcmdentry();
1188}
1189
1190
1191
1192/*
1193 * Search for a command. This is called before we fork so that the
1194 * location of the command will be available in the parent as well as
1195 * the child. The check for "goodname" is an overly conservative
1196 * check that the name will not be subject to expansion.
1197 */
1198
1199static void
1200prehash(union node *n)
1201{
1202 struct cmdentry entry;
1203
1204 if (n && n->type == NCMD && n->ncmd.args)
1205 if (goodname(n->ncmd.args->narg.text))
1206 find_command(n->ncmd.args->narg.text, &entry, 0,
1207 pathval());
1208}
1209
1210
1211
1212/*
1213 * Builtin commands. Builtin commands whose functions are closely
1214 * tied to evaluation are implemented here.
1215 */
1216
1217/*
1218 * No command given, a bltin command with no arguments, or a bltin command
1219 * with an invalid name.
1220 */
1221
1222int
1223bltincmd(int argc, char **argv)
1224{
1225 if (argc > 1) {
1226 out2fmt_flush("%s: not found\n", argv[1]);
1227 return 127;
1228 }
1229 /*
1230 * Preserve exitstatus of a previous possible redirection
1231 * as POSIX mandates
1232 */
1233 return exitstatus;
1234}
1235
1236
1237/*
1238 * Handle break and continue commands. Break, continue, and return are
1239 * all handled by setting the evalskip flag. The evaluation routines
1240 * above all check this flag, and if it is set they start skipping
1241 * commands rather than executing them. The variable skipcount is
1242 * the number of loops to break/continue, or the number of function
1243 * levels to return. (The latter is always 1.) It should probably
1244 * be an error to break out of more loops than exist, but it isn't
1245 * in the standard shell so we don't make it one here.
1246 */
1247
1248int
1249breakcmd(int argc, char **argv)
1250{
1251 long n;
1252 char *end;
1253
1254 if (argc > 1) {
1255 /* Allow arbitrarily large numbers. */
1256 n = strtol(argv[1], &end, 10);
1257 if (!is_digit(argv[1][0]) || *end != '\0')
1258 error("Illegal number: %s", argv[1]);
1259 } else
1260 n = 1;
1261 if (n > loopnest)
1262 n = loopnest;
1263 if (n > 0) {
1264 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1265 skipcount = n;
1266 }
1267 return 0;
1268}
1269
1270/*
1271 * The `command' command.
1272 */
1273int
1274commandcmd(int argc __unused, char **argv __unused)
1275{
1276 const char *path;
1277 int ch;
1278 int cmd = -1;
1279
1280 path = bltinlookup("PATH", 1);
1281
1282 while ((ch = nextopt("pvV")) != '\0') {
1283 switch (ch) {
1284 case 'p':
1285 path = _PATH_STDPATH;
1286 break;
1287 case 'v':
1288 cmd = TYPECMD_SMALLV;
1289 break;
1290 case 'V':
1291 cmd = TYPECMD_BIGV;
1292 break;
1293 }
1294 }
1295
1296 if (cmd != -1) {
1297 if (*argptr == NULL || argptr[1] != NULL)
1298 error("wrong number of arguments");
1299 return typecmd_impl(2, argptr - 1, cmd, path);
1300 }
1301 if (*argptr != NULL)
1302 error("commandcmd bad call");
1303
1304 /*
1305 * Do nothing successfully if no command was specified;
1306 * ksh also does this.
1307 */
1308 return 0;
1309}
1310
1311
1312/*
1313 * The return command.
1314 */
1315
1316int
1317returncmd(int argc, char **argv)
1318{
1319 int ret = argc > 1 ? number(argv[1]) : oexitstatus;
1320
1321 evalskip = SKIPRETURN;
1322 skipcount = 1;
1323 return ret;
1324}
1325
1326
1327int
1328falsecmd(int argc __unused, char **argv __unused)
1329{
1330 return 1;
1331}
1332
1333
1334int
1335truecmd(int argc __unused, char **argv __unused)
1336{
1337 return 0;
1338}
1339
1340
1341int
1342execcmd(int argc, char **argv)
1343{
1344 /*
1345 * Because we have historically not supported any options,
1346 * only treat "--" specially.
1347 */
1348 if (argc > 1 && strcmp(argv[1], "--") == 0)
1349 argc--, argv++;
1350 if (argc > 1) {
1351 struct strlist *sp;
1352
1353 iflag = 0; /* exit on error */
1354 mflag = 0;
1355 optschanged();
1356 for (sp = cmdenviron; sp ; sp = sp->next)
1357 setvareq(sp->text, VEXPORT|VSTACK);
1358 shellexec(argv + 1, environment(), pathval(), 0);
1359
1360 }
1361 return 0;
1362}
1363
1364
1365int
1366timescmd(int argc __unused, char **argv __unused)
1367{
1368 struct rusage ru;
1369 long shumins, shsmins, chumins, chsmins;
1370 double shusecs, shssecs, chusecs, chssecs;
1371
1372 if (getrusage(RUSAGE_SELF, &ru) < 0)
1373 return 1;
1374 shumins = ru.ru_utime.tv_sec / 60;
1375 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.;
1376 shsmins = ru.ru_stime.tv_sec / 60;
1377 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.;
1378 if (getrusage(RUSAGE_CHILDREN, &ru) < 0)
1379 return 1;
1380 chumins = ru.ru_utime.tv_sec / 60;
1381 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.;
1382 chsmins = ru.ru_stime.tv_sec / 60;
1383 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.;
1384 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins,
1385 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs);
1386 return 0;
1387}
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