eval.c revision 1.191 1 /* $NetBSD: eval.c,v 1.191 2023/12/25 04:52:38 kre Exp $ */
2
3 /*-
4 * Copyright (c) 1993
5 * The Regents of the University of California. 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 <sys/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
39 #else
40 __RCSID("$NetBSD: eval.c,v 1.191 2023/12/25 04:52:38 kre Exp $");
41 #endif
42 #endif /* not lint */
43
44 #include <stdbool.h>
45 #include <stdlib.h>
46 #include <signal.h>
47 #include <stdio.h>
48 #include <string.h>
49 #include <errno.h>
50 #include <limits.h>
51 #include <unistd.h>
52 #include <sys/fcntl.h>
53 #include <sys/stat.h>
54 #include <sys/times.h>
55 #include <sys/param.h>
56 #include <sys/types.h>
57 #include <sys/wait.h>
58 #include <sys/sysctl.h>
59
60 /*
61 * Evaluate a command.
62 */
63
64 #include "shell.h"
65 #include "nodes.h"
66 #include "syntax.h"
67 #include "expand.h"
68 #include "parser.h"
69 #include "jobs.h"
70 #include "eval.h"
71 #include "builtins.h"
72 #include "options.h"
73 #include "exec.h"
74 #include "redir.h"
75 #include "input.h"
76 #include "output.h"
77 #include "trap.h"
78 #include "var.h"
79 #include "memalloc.h"
80 #include "error.h"
81 #include "show.h"
82 #include "mystring.h"
83 #include "main.h"
84 #ifndef SMALL
85 #include "nodenames.h"
86 #include "myhistedit.h"
87 #endif
88
89
90 STATIC struct skipsave s_k_i_p;
91 #define evalskip (s_k_i_p.state)
92 #define skipcount (s_k_i_p.count)
93
94 STATIC int loopnest; /* current loop nesting level */
95 STATIC int funcnest; /* depth of function calls */
96 STATIC int builtin_flags; /* evalcommand flags for builtins */
97 /*
98 * Base function nesting level inside a dot command. Set to 0 initially
99 * and to (funcnest + 1) before every dot command to enable
100 * 1) detection of being in a file sourced by a dot command and
101 * 2) counting of function nesting in that file for the implementation
102 * of the return command.
103 * The value is reset to its previous value after the dot command.
104 */
105 STATIC int dot_funcnest;
106
107
108 const char *commandname;
109 struct strlist *cmdenviron;
110 int exitstatus; /* exit status of last command */
111 int back_exitstatus; /* exit status of backquoted command */
112
113
114 STATIC void evalloop(union node *, int);
115 STATIC void evalfor(union node *, int);
116 STATIC void evalcase(union node *, int);
117 STATIC void evalsubshell(union node *, int);
118 STATIC void expredir(union node *);
119 STATIC void evalredir(union node *, int);
120 STATIC void evalpipe(union node *);
121 STATIC void evalcommand(union node *, int, struct backcmd *);
122 STATIC void prehash(union node *);
123
124 STATIC char *find_dot_file(char *);
125
126 /*
127 * Called to reset things after an exception.
128 */
129
130 #ifdef mkinit
131 INCLUDE "eval.h"
132
133 RESET {
134 reset_eval();
135 }
136
137 SHELLPROC {
138 exitstatus = 0;
139 }
140 #endif
141
142 void
143 reset_eval(void)
144 {
145 evalskip = SKIPNONE;
146 dot_funcnest = 0;
147 loopnest = 0;
148 funcnest = 0;
149 }
150
151 static int
152 sh_pipe(int fds[2])
153 {
154 int nfd;
155
156 if (pipe(fds))
157 return -1;
158
159 if (fds[0] < 3) {
160 nfd = fcntl(fds[0], F_DUPFD, 3);
161 if (nfd != -1) {
162 close(fds[0]);
163 fds[0] = nfd;
164 }
165 }
166
167 if (fds[1] < 3) {
168 nfd = fcntl(fds[1], F_DUPFD, 3);
169 if (nfd != -1) {
170 close(fds[1]);
171 fds[1] = nfd;
172 }
173 }
174 return 0;
175 }
176
177
178 /*
179 * The eval command.
180 */
181
182 int
183 evalcmd(int argc, char **argv)
184 {
185 char *p;
186 char *concat;
187 char **ap;
188
189 if (argc > 1) {
190 p = argv[1];
191 if (argc > 2) {
192 STARTSTACKSTR(concat);
193 ap = argv + 2;
194 for (;;) {
195 while (*p)
196 STPUTC(*p++, concat);
197 if ((p = *ap++) == NULL)
198 break;
199 STPUTC(' ', concat);
200 }
201 STPUTC('\0', concat);
202 p = grabstackstr(concat);
203 }
204 evalstring(p, builtin_flags & EV_TESTED);
205 } else
206 exitstatus = 0;
207 return exitstatus;
208 }
209
210
211 /*
212 * Execute a command or commands contained in a string.
213 */
214
215 void
216 evalstring(char *s, int flag)
217 {
218 union node *n;
219 struct stackmark smark;
220 int last;
221 int any;
222
223 last = flag & EV_EXIT;
224 flag &= ~EV_EXIT;
225
226 setstackmark(&smark);
227 setinputstring(s, 1, line_number);
228
229 any = 0; /* to determine if exitstatus will have been set */
230 while ((n = parsecmd(0)) != NEOF) {
231 XTRACE(DBG_EVAL, ("evalstring: "), showtree(n));
232 if (n && nflag == 0) {
233 if (last && at_eof())
234 evaltree(n, flag | EV_EXIT);
235 else
236 evaltree(n, flag);
237 any = 1;
238 if (evalskip)
239 break;
240 }
241 rststackmark(&smark);
242 }
243 popfile();
244 popstackmark(&smark);
245 if (!any)
246 exitstatus = 0;
247 if (last)
248 exraise(EXEXIT);
249 }
250
251
252
253 /*
254 * Evaluate a parse tree. The value is left in the global variable
255 * exitstatus.
256 */
257
258 void
259 evaltree(union node *n, int flags)
260 {
261 bool do_etest;
262 int sflags = flags & ~EV_EXIT;
263 union node *next;
264 struct stackmark smark;
265
266 do_etest = false;
267 if (n == NULL || nflag) {
268 VTRACE(DBG_EVAL, ("evaltree(%s) called\n",
269 n == NULL ? "NULL" : "-n"));
270 if (nflag == 0)
271 exitstatus = 0;
272 goto out2;
273 }
274
275 setstackmark(&smark);
276 do {
277 #ifndef SMALL
278 displayhist = 1; /* show history substitutions done with fc */
279 #endif
280 next = NULL;
281 CTRACE(DBG_EVAL, ("pid %d, evaltree(%p: %s(%d), %#x) called\n",
282 getpid(), n, NODETYPENAME(n->type), n->type, flags));
283 /*
284 if (n->type != NCMD && traps_invalid)
285 free_traps();
286 */
287 switch (n->type) {
288 case NSEMI:
289 evaltree(n->nbinary.ch1, sflags);
290 if (nflag || evalskip)
291 goto out1;
292 next = n->nbinary.ch2;
293 break;
294 case NAND:
295 evaltree(n->nbinary.ch1, EV_TESTED);
296 if (nflag || evalskip || exitstatus != 0)
297 goto out1;
298 next = n->nbinary.ch2;
299 break;
300 case NOR:
301 evaltree(n->nbinary.ch1, EV_TESTED);
302 if (nflag || evalskip || exitstatus == 0)
303 goto out1;
304 next = n->nbinary.ch2;
305 break;
306 case NREDIR:
307 if (traps_invalid)
308 free_traps();
309 evalredir(n, flags);
310 break;
311 case NSUBSHELL:
312 evalsubshell(n, flags);
313 do_etest = !(flags & EV_TESTED);
314 break;
315 case NBACKGND:
316 if (traps_invalid)
317 free_traps();
318 evalsubshell(n, flags);
319 break;
320 case NIF: {
321 if (traps_invalid)
322 free_traps();
323 evaltree(n->nif.test, EV_TESTED);
324 if (nflag || evalskip)
325 goto out1;
326 if (exitstatus == 0)
327 next = n->nif.ifpart;
328 else if (n->nif.elsepart)
329 next = n->nif.elsepart;
330 else
331 exitstatus = 0;
332 break;
333 }
334 case NWHILE:
335 case NUNTIL:
336 if (traps_invalid)
337 free_traps();
338 evalloop(n, sflags);
339 break;
340 case NFOR:
341 if (traps_invalid)
342 free_traps();
343 evalfor(n, sflags);
344 break;
345 case NCASE:
346 if (traps_invalid)
347 free_traps();
348 evalcase(n, sflags);
349 break;
350 case NDEFUN:
351 if (traps_invalid)
352 free_traps();
353 CTRACE(DBG_EVAL, ("Defining fn %s @%d%s\n",
354 n->narg.text, n->narg.lineno,
355 fnline1 ? " LINENO=1" : ""));
356 defun(n->narg.text, n->narg.next, n->narg.lineno);
357 exitstatus = 0;
358 break;
359 case NNOT:
360 evaltree(n->nnot.com, EV_TESTED);
361 exitstatus = !exitstatus;
362 break;
363 case NDNOT:
364 evaltree(n->nnot.com, EV_TESTED);
365 if (exitstatus != 0)
366 exitstatus = 1;
367 break;
368 case NPIPE:
369 if (traps_invalid)
370 free_traps();
371 evalpipe(n);
372 do_etest = !(flags & EV_TESTED);
373 break;
374 case NCMD:
375 evalcommand(n, flags, NULL);
376 do_etest = !(flags & EV_TESTED);
377 break;
378 default:
379 #ifdef NODETYPENAME
380 out1fmt("Node type = %d(%s)\n",
381 n->type, NODETYPENAME(n->type));
382 #else
383 out1fmt("Node type = %d\n", n->type);
384 #endif
385 flushout(&output);
386 break;
387 }
388 n = next;
389 rststackmark(&smark);
390 } while(n != NULL);
391 out1:
392 popstackmark(&smark);
393 out2:
394 if (pendingsigs)
395 dotrap();
396 if (eflag && exitstatus != 0 && do_etest)
397 exitshell(exitstatus);
398 if (flags & EV_EXIT)
399 exraise(EXEXIT);
400 }
401
402
403 STATIC void
404 evalloop(union node *n, int flags)
405 {
406 int status;
407
408 loopnest++;
409 status = 0;
410
411 CTRACE(DBG_EVAL, ("evalloop %s:", NODETYPENAME(n->type)));
412 VXTRACE(DBG_EVAL, (" "), showtree(n->nbinary.ch1));
413 VXTRACE(DBG_EVAL, ("evalloop do: "), showtree(n->nbinary.ch2));
414 VTRACE(DBG_EVAL, ("evalloop done\n"));
415 CTRACE(DBG_EVAL, ("\n"));
416
417 for (;;) {
418 evaltree(n->nbinary.ch1, EV_TESTED);
419 if (nflag)
420 break;
421 if (evalskip) {
422 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) {
423 evalskip = SKIPNONE;
424 continue;
425 }
426 if (evalskip == SKIPBREAK && --skipcount <= 0)
427 evalskip = SKIPNONE;
428 if (evalskip == SKIPFUNC || evalskip == SKIPFILE)
429 status = exitstatus;
430 break;
431 }
432 if (n->type == NWHILE) {
433 if (exitstatus != 0)
434 break;
435 } else {
436 if (exitstatus == 0)
437 break;
438 }
439 evaltree(n->nbinary.ch2, flags & EV_TESTED);
440 status = exitstatus;
441 if (evalskip)
442 goto skipping;
443 }
444 loopnest--;
445 exitstatus = status;
446 }
447
448
449
450 STATIC void
451 evalfor(union node *n, int flags)
452 {
453 struct arglist arglist;
454 union node *argp;
455 struct strlist *sp;
456 struct stackmark smark;
457 int status;
458
459 status = nflag ? exitstatus : 0;
460
461 setstackmark(&smark);
462 arglist.lastp = &arglist.list;
463 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
464 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
465 if (evalskip)
466 goto out;
467 }
468 *arglist.lastp = NULL;
469
470 loopnest++;
471 for (sp = arglist.list ; sp ; sp = sp->next) {
472 line_number = n->nfor.lineno;
473 if (xflag) {
474 outxstr(expandstr(ps4val(), line_number));
475 outxstr("for ");
476 outxstr(n->nfor.var);
477 outxc('=');
478 outxshstr(sp->text);
479 outxc('\n');
480 flushout(outx);
481 }
482
483 setvar(n->nfor.var, sp->text, 0);
484 evaltree(n->nfor.body, flags & EV_TESTED);
485 status = exitstatus;
486 if (nflag)
487 break;
488 if (evalskip) {
489 if (evalskip == SKIPCONT && --skipcount <= 0) {
490 evalskip = SKIPNONE;
491 continue;
492 }
493 if (evalskip == SKIPBREAK && --skipcount <= 0)
494 evalskip = SKIPNONE;
495 break;
496 }
497 }
498 loopnest--;
499 exitstatus = status;
500 out:
501 popstackmark(&smark);
502 }
503
504
505
506 STATIC void
507 evalcase(union node *n, int flags)
508 {
509 union node *cp, *ncp;
510 union node *patp;
511 struct arglist arglist;
512 struct stackmark smark;
513 int status = 0;
514
515 setstackmark(&smark);
516 arglist.lastp = &arglist.list;
517 line_number = n->ncase.lineno;
518 expandarg(n->ncase.expr, &arglist, EXP_TILDE);
519 for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) {
520 for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) {
521 line_number = patp->narg.lineno;
522 if (casematch(patp, arglist.list->text)) {
523 while (cp != NULL && evalskip == 0 &&
524 nflag == 0) {
525 if (cp->type == NCLISTCONT)
526 ncp = cp->nclist.next;
527 else
528 ncp = NULL;
529 line_number = cp->nclist.lineno;
530 evaltree(cp->nclist.body, flags);
531 status = exitstatus;
532 cp = ncp;
533 }
534 goto out;
535 }
536 }
537 }
538 out:
539 exitstatus = status;
540 popstackmark(&smark);
541 }
542
543
544
545 /*
546 * Kick off a subshell to evaluate a tree.
547 */
548
549 STATIC void
550 evalsubshell(union node *n, int flags)
551 {
552 struct job *jp= NULL;
553 int backgnd = (n->type == NBACKGND);
554
555 expredir(n->nredir.redirect);
556 if (xflag && n->nredir.redirect) {
557 union node *rn;
558
559 outxstr(expandstr(ps4val(), line_number));
560 outxstr("using redirections:");
561 for (rn = n->nredir.redirect; rn; rn = rn->nfile.next)
562 (void) outredir(outx, rn, ' ');
563 outxstr(" do subshell ("/*)*/);
564 if (backgnd)
565 outxstr(/*(*/") &");
566 outxc('\n');
567 flushout(outx);
568 }
569 INTOFF;
570 if ((!backgnd && flags & EV_EXIT && !have_traps() && !anyjobs()) ||
571 forkshell(jp = makejob(n, 1), n, backgnd?FORK_BG:FORK_FG) == 0) {
572 if (backgnd)
573 flags &=~ EV_TESTED;
574 INTON;
575 redirect(n->nredir.redirect, REDIR_KEEP);
576 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */
577 } else if (backgnd)
578 exitstatus = 0;
579 else
580 exitstatus = waitforjob(jp);
581 INTON;
582
583 if (!backgnd && xflag && n->nredir.redirect) {
584 outxstr(expandstr(ps4val(), line_number));
585 outxstr(/*(*/") done subshell\n");
586 flushout(outx);
587 }
588 }
589
590
591
592 /*
593 * Compute the names of the files in a redirection list.
594 */
595
596 STATIC void
597 expredir(union node *n)
598 {
599 union node *redir;
600
601 for (redir = n ; redir ; redir = redir->nfile.next) {
602 struct arglist fn;
603
604 fn.lastp = &fn.list;
605 switch (redir->type) {
606 case NFROMTO:
607 case NFROM:
608 case NTO:
609 case NCLOBBER:
610 case NAPPEND:
611 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
612 redir->nfile.expfname = fn.list->text;
613 break;
614 case NFROMFD:
615 case NTOFD:
616 if (redir->ndup.vname) {
617 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
618 fixredir(redir, fn.list->text, 1);
619 }
620 break;
621 case NHERE:
622 redir->nhere.text = redir->nhere.doc->narg.text;
623 break;
624 case NXHERE:
625 redir->nhere.text = expandhere(redir->nhere.doc);
626 break;
627 }
628 }
629 }
630
631 /*
632 * Perform redirections for a compound command, and then do it (and restore)
633 */
634 STATIC void
635 evalredir(union node *n, int flags)
636 {
637 struct jmploc jmploc;
638 struct jmploc * const savehandler = handler;
639 volatile int in_redirect = 1;
640 const char * volatile PS4 = NULL;
641
642 expredir(n->nredir.redirect);
643
644 if (xflag && n->nredir.redirect) {
645 union node *rn;
646
647 outxstr(PS4 = expandstr(ps4val(), line_number));
648 outxstr("using redirections:");
649 for (rn = n->nredir.redirect; rn != NULL; rn = rn->nfile.next)
650 (void) outredir(outx, rn, ' ');
651 outxstr(" do {\n"); /* } */
652 flushout(outx);
653 }
654
655 if (setjmp(jmploc.loc)) {
656 int e;
657
658 handler = savehandler;
659 e = exception;
660 popredir();
661 if (PS4 != NULL) {
662 outxstr(PS4);
663 /* { */ outxstr("} failed\n");
664 flushout(outx);
665 }
666 if (e == EXERROR || e == EXEXEC) {
667 if (in_redirect) {
668 exitstatus = 2;
669 return;
670 }
671 }
672 longjmp(handler->loc, 1);
673 } else {
674 INTOFF;
675 handler = &jmploc;
676 redirect(n->nredir.redirect, REDIR_PUSH | REDIR_KEEP);
677 in_redirect = 0;
678 INTON;
679 evaltree(n->nredir.n, flags);
680 }
681 INTOFF;
682 handler = savehandler;
683 popredir();
684 INTON;
685
686 if (PS4 != NULL) {
687 outxstr(PS4);
688 /* { */ outxstr("} done\n");
689 flushout(outx);
690 }
691 }
692
693
694 /*
695 * Evaluate a pipeline. All the processes in the pipeline are children
696 * of the process creating the pipeline. (This differs from some versions
697 * of the shell, which make the last process in a pipeline the parent
698 * of all the rest.)
699 */
700
701 STATIC void
702 evalpipe(union node *n)
703 {
704 struct job *jp;
705 struct nodelist *lp;
706 int pipelen;
707 int prevfd;
708 int pip[2];
709
710 CTRACE(DBG_EVAL, ("evalpipe(%p) called\n", n));
711 pipelen = 0;
712 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
713 pipelen++;
714 INTOFF;
715 jp = makejob(n, pipelen);
716 prevfd = -1;
717 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
718 prehash(lp->n);
719 pip[1] = -1;
720 if (lp->next) {
721 if (sh_pipe(pip) < 0) {
722 if (prevfd >= 0)
723 close(prevfd);
724 error("Pipe call failed: %s", strerror(errno));
725 }
726 }
727 if (forkshell(jp, lp->n,
728 n->npipe.backgnd ? FORK_BG : FORK_FG) == 0) {
729 INTON;
730 if (prevfd > 0)
731 movefd(prevfd, 0);
732 if (pip[1] >= 0) {
733 close(pip[0]);
734 movefd(pip[1], 1);
735 }
736 evaltree(lp->n, EV_EXIT);
737 }
738 if (prevfd >= 0)
739 close(prevfd);
740 prevfd = pip[0];
741 close(pip[1]);
742 }
743 if (n->npipe.backgnd == 0) {
744 exitstatus = waitforjob(jp);
745 CTRACE(DBG_EVAL, ("evalpipe: job done exit status %d\n",
746 exitstatus));
747 } else
748 exitstatus = 0;
749 INTON;
750 }
751
752
753
754 /*
755 * Execute a command inside back quotes. If it's a builtin command, we
756 * want to save its output in a block obtained from malloc. Otherwise
757 * we fork off a subprocess and get the output of the command via a pipe.
758 * Should be called with interrupts off.
759 */
760
761 void
762 evalbackcmd(union node *n, struct backcmd *result)
763 {
764 int pip[2];
765 struct job *jp;
766 struct stackmark smark; /* unnecessary (because we fork) */
767
768 result->fd = -1;
769 result->buf = NULL;
770 result->nleft = 0;
771 result->jp = NULL;
772
773 if (nflag || n == NULL)
774 goto out;
775
776 setstackmark(&smark);
777
778 #ifdef notyet
779 /*
780 * For now we disable executing builtins in the same
781 * context as the shell, because we are not keeping
782 * enough state to recover from changes that are
783 * supposed only to affect subshells. eg. echo "`cd /`"
784 */
785 if (n->type == NCMD) {
786 exitstatus = oexitstatus; /* XXX o... no longer exists */
787 evalcommand(n, EV_BACKCMD, result);
788 } else
789 #endif
790 {
791 INTOFF;
792 if (sh_pipe(pip) < 0)
793 error("Pipe call failed");
794 jp = makejob(n, 1);
795 if (forkshell(jp, n, FORK_NOJOB) == 0) {
796 FORCEINTON;
797 close(pip[0]);
798 movefd(pip[1], 1);
799 evaltree(n, EV_EXIT);
800 /* NOTREACHED */
801 }
802 close(pip[1]);
803 result->fd = pip[0];
804 result->jp = jp;
805 INTON;
806 }
807 popstackmark(&smark);
808 out:
809 CTRACE(DBG_EVAL, ("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
810 result->fd, result->buf, result->nleft, result->jp));
811 }
812
813 const char *
814 syspath(void)
815 {
816 static char *sys_path = NULL;
817 static int mib[] = {CTL_USER, USER_CS_PATH};
818 static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin";
819 size_t len;
820
821 if (sys_path == NULL) {
822 if (sysctl(mib, 2, 0, &len, 0, 0) != -1 &&
823 (sys_path = ckmalloc(len + 5)) != NULL &&
824 sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) {
825 memcpy(sys_path, "PATH=", 5);
826 } else {
827 ckfree(sys_path);
828 /* something to keep things happy */
829 sys_path = def_path;
830 }
831 }
832 return sys_path;
833 }
834
835 static int
836 parse_command_args(int argc, char **argv, int *use_syspath)
837 {
838 int sv_argc = argc;
839 char *cp, c;
840
841 *use_syspath = 0;
842
843 for (;;) {
844 argv++;
845 if (--argc == 0)
846 break;
847 cp = *argv;
848 if (*cp++ != '-')
849 break;
850 if (*cp == '-' && cp[1] == 0) {
851 argv++;
852 argc--;
853 break;
854 }
855 while ((c = *cp++)) {
856 switch (c) {
857 case 'p':
858 *use_syspath = 1;
859 break;
860 default:
861 /* run 'typecmd' for other options */
862 return 0;
863 }
864 }
865 }
866 return sv_argc - argc;
867 }
868
869 int vforked = 0;
870
871 /*
872 * Execute a simple command.
873 */
874
875 STATIC void
876 evalcommand(union node *cmd, int flgs, struct backcmd *backcmd)
877 {
878 struct stackmark smark;
879 union node *argp;
880 struct arglist arglist;
881 struct arglist varlist;
882 volatile int flags = flgs;
883 char ** volatile argv;
884 volatile int argc;
885 char **envp;
886 int varflag;
887 struct strlist *sp;
888 volatile int mode;
889 int pip[2];
890 struct cmdentry cmdentry;
891 struct job * volatile jp;
892 struct jmploc jmploc;
893 struct jmploc *volatile savehandler = NULL;
894 const char *volatile savecmdname;
895 volatile struct shparam saveparam;
896 struct localvar *volatile savelocalvars;
897 struct parsefile *volatile savetopfile;
898 volatile int e;
899 char * volatile lastarg;
900 const char * volatile path = pathval();
901 volatile int temp_path;
902 const int savefuncline = funclinebase;
903 const int savefuncabs = funclineabs;
904 volatile int cmd_flags = 0;
905
906 vforked = 0;
907 /* First expand the arguments. */
908 CTRACE(DBG_EVAL, ("evalcommand(%p, %d) called [%s]\n", cmd, flags,
909 cmd->ncmd.args ? cmd->ncmd.args->narg.text : ""));
910 setstackmark(&smark);
911 back_exitstatus = 0;
912
913 line_number = cmd->ncmd.lineno;
914
915 arglist.lastp = &arglist.list;
916 varflag = 1;
917 /* Expand arguments, ignoring the initial 'name=value' ones */
918 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
919 if (varflag && isassignment(argp->narg.text))
920 continue;
921 varflag = 0;
922 line_number = argp->narg.lineno;
923 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
924 }
925 *arglist.lastp = NULL;
926
927 expredir(cmd->ncmd.redirect);
928
929 /* Now do the initial 'name=value' ones we skipped above */
930 varlist.lastp = &varlist.list;
931 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
932 line_number = argp->narg.lineno;
933 if (!isassignment(argp->narg.text))
934 break;
935 /* EXP_CASE handles CTL* chars in expansions properly */
936 expandarg(argp, &varlist, EXP_VARTILDE | EXP_CASE);
937 }
938 *varlist.lastp = NULL;
939
940 argc = 0;
941 for (sp = arglist.list ; sp ; sp = sp->next)
942 argc++;
943 argv = stalloc(sizeof (char *) * (argc + 1));
944
945 for (sp = arglist.list ; sp ; sp = sp->next) {
946 VTRACE(DBG_EVAL, ("evalcommand arg: %s\n", sp->text));
947 *argv++ = sp->text;
948 }
949 *argv = NULL;
950 lastarg = NULL;
951 if (iflag && funcnest == 0 && argc > 0)
952 lastarg = argv[-1];
953 argv -= argc;
954
955 /* Print the command if xflag is set. */
956 if (xflag) {
957 char sep = 0;
958 union node *rn;
959
960 outxstr(expandstr(ps4val(), line_number));
961 for (sp = varlist.list ; sp ; sp = sp->next) {
962 char *p;
963
964 if (sep != 0)
965 outxc(sep);
966
967 /*
968 * The "var=" part should not be quoted, regardless
969 * of the value, or it would not represent an
970 * assignment, but rather a command
971 */
972 p = strchr(sp->text, '=');
973 if (p != NULL) {
974 *p = '\0'; /*XXX*/
975 outxshstr(sp->text);
976 outxc('=');
977 *p++ = '='; /*XXX*/
978 } else
979 p = sp->text;
980 outxshstr(p);
981 sep = ' ';
982 }
983 for (sp = arglist.list ; sp ; sp = sp->next) {
984 if (sep != 0)
985 outxc(sep);
986 outxshstr(sp->text);
987 sep = ' ';
988 }
989 for (rn = cmd->ncmd.redirect; rn; rn = rn->nfile.next)
990 if (outredir(outx, rn, sep))
991 sep = ' ';
992 outxc('\n');
993 flushout(outx);
994 }
995
996 /* Now locate the command. */
997 if (argc == 0) {
998 /*
999 * the empty command begins as a normal builtin, and
1000 * remains that way while redirects are processed, then
1001 * will become special before we get to doing the
1002 * var assigns.
1003 */
1004 cmdentry.cmdtype = CMDBUILTIN;
1005 cmdentry.u.bltin = bltincmd;
1006 VTRACE(DBG_CMDS, ("No command name, assume \"command\"\n"));
1007 } else {
1008 static const char PATH[] = "PATH=";
1009
1010 /*
1011 * Modify the command lookup path, if a PATH= assignment
1012 * is present
1013 */
1014 for (sp = varlist.list; sp; sp = sp->next)
1015 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
1016 path = sp->text + sizeof(PATH) - 1;
1017
1018 do {
1019 int argsused, use_syspath;
1020
1021 find_command(argv[0], &cmdentry, cmd_flags, path);
1022 VTRACE(DBG_CMDS, ("Command %s type %d\n", argv[0],
1023 cmdentry.cmdtype));
1024 #if 0
1025 /*
1026 * This short circuits all of the processing that
1027 * should be done (including processing the
1028 * redirects), so just don't ...
1029 *
1030 * (eventually this whole #if'd block will vanish)
1031 */
1032 if (cmdentry.cmdtype == CMDUNKNOWN) {
1033 exitstatus = 127;
1034 flushout(&errout);
1035 goto out;
1036 }
1037 #endif
1038
1039 /* implement the 'command' builtin here */
1040 if (cmdentry.cmdtype != CMDBUILTIN ||
1041 cmdentry.u.bltin != bltincmd)
1042 break;
1043 VTRACE(DBG_CMDS, ("Command \"command\"\n"));
1044 cmd_flags |= DO_NOFUNC;
1045 argsused = parse_command_args(argc, argv, &use_syspath);
1046 if (argsused == 0) {
1047 /* use 'type' builtin to display info */
1048 VTRACE(DBG_CMDS,
1049 ("Command \"command\" -> \"type\"\n"));
1050 cmdentry.u.bltin = typecmd;
1051 break;
1052 }
1053 argc -= argsused;
1054 argv += argsused;
1055 if (use_syspath)
1056 path = syspath() + 5;
1057 } while (argc != 0);
1058 if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
1059 /* posix mandates that 'command <splbltin>' act as if
1060 <splbltin> was a normal builtin */
1061 cmdentry.cmdtype = CMDBUILTIN;
1062 }
1063
1064 /*
1065 * When traps are invalid, we permit the following:
1066 * trap
1067 * command trap
1068 * eval trap
1069 * command eval trap
1070 * eval command trap
1071 * without zapping the traps completely, in all other cases we do.
1072 * Function calls also do not zap the traps (but commands they execute
1073 * probably will) - this allows a function like
1074 * trapstate() { trap -p; }
1075 * called as save_traps=$(trapstate).
1076 *
1077 * The test here permits eval "anything" but when evalstring() comes
1078 * back here again, the "anything" will be validated.
1079 * This means we can actually do:
1080 * eval eval eval command eval eval command trap
1081 * as long as we end up with just "trap"
1082 *
1083 * We permit "command" by allowing CMDBUILTIN as well as CMDSPLBLTIN
1084 *
1085 * trapcmd() takes care of doing free_traps() if it is needed there.
1086 */
1087 if (traps_invalid &&
1088 cmdentry.cmdtype != CMDFUNCTION &&
1089 ((cmdentry.cmdtype!=CMDSPLBLTIN && cmdentry.cmdtype!=CMDBUILTIN) ||
1090 (cmdentry.u.bltin != trapcmd && cmdentry.u.bltin != evalcmd)))
1091 free_traps();
1092
1093 /* Fork off a child process if necessary. */
1094 if (cmd->ncmd.backgnd
1095 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
1096 && (have_traps() || (flags & EV_EXIT) == 0))
1097 #ifdef notyet /* EV_BACKCMD is never set currently */
1098 /* this will need more work if/when it gets used */
1099 || ((flags & EV_BACKCMD) != 0
1100 && (cmdentry.cmdtype != CMDBUILTIN
1101 && cmdentry.cmdtype != CMDSPLBLTIN)
1102 || cmdentry.u.bltin == dotcmd
1103 || cmdentry.u.bltin == evalcmd)
1104 #endif
1105 ) {
1106 INTOFF;
1107 jp = makejob(cmd, 1);
1108 mode = cmd->ncmd.backgnd;
1109 if (flags & EV_BACKCMD) {
1110 mode = FORK_NOJOB;
1111 if (sh_pipe(pip) < 0)
1112 error("Pipe call failed");
1113 }
1114 #ifdef DO_SHAREDVFORK
1115 /* It is essential that if DO_SHAREDVFORK is defined that the
1116 * child's address space is actually shared with the parent as
1117 * we rely on this.
1118 */
1119 if (usefork == 0 && cmdentry.cmdtype == CMDNORMAL &&
1120 (!cmd->ncmd.backgnd || cmd->ncmd.redirect == NULL)) {
1121 pid_t pid;
1122 int serrno;
1123
1124 savelocalvars = localvars;
1125 localvars = NULL;
1126 vforked = 1;
1127 VFORK_BLOCK
1128 switch (pid = vfork()) {
1129 case -1:
1130 serrno = errno;
1131 VTRACE(DBG_EVAL, ("vfork() failed, errno=%d\n",
1132 serrno));
1133 INTON;
1134 error("Cannot vfork (%s)", strerror(serrno));
1135 break;
1136 case 0:
1137 /* Make sure that exceptions only unwind to
1138 * after the vfork(2)
1139 */
1140 SHELL_FORKED();
1141 if (setjmp(jmploc.loc)) {
1142 VTRACE(DBG_EVAL|DBG_ERRS|
1143 DBG_PROCS|DBG_CMDS|DBG_TRAP,
1144 ("vfork child exit exception:%d "
1145 "exitstatus:%d exerrno:%d\n",
1146 exception, exitstatus, exerrno));
1147
1148 if (exception == EXSHELLPROC) {
1149 /*
1150 * We can't progress with the
1151 * vfork, so, set vforked = 2
1152 * so the parent knows,
1153 * and _exit();
1154 */
1155 vforked = 2;
1156 _exit(0);
1157 } else {
1158 _exit(exception == EXEXIT ?
1159 exitstatus : exerrno);
1160 }
1161 }
1162 savehandler = handler;
1163 handler = &jmploc;
1164 listmklocal(varlist.list,
1165 VDOEXPORT | VEXPORT | VNOFUNC);
1166 forkchild(jp, cmd, mode, vforked);
1167 break;
1168 default:
1169 VFORK_UNDO();
1170 /* restore from vfork(2) */
1171 CTRACE(DBG_PROCS|DBG_CMDS,
1172 ("parent after vfork - vforked=%d\n",
1173 vforked));
1174 handler = savehandler;
1175 poplocalvars();
1176 localvars = savelocalvars;
1177 if (vforked == 2) {
1178 vforked = 0;
1179
1180 (void)waitpid(pid, NULL, 0);
1181 /*
1182 * We need to progress in a
1183 * normal fork fashion
1184 */
1185 goto normal_fork;
1186 }
1187 /*
1188 * Here the child has left home,
1189 * getting on with its life, so
1190 * so must we...
1191 */
1192 vforked = 0;
1193 forkparent(jp, cmd, mode, pid);
1194 goto parent;
1195 }
1196 VFORK_END
1197 } else {
1198 normal_fork:
1199 #endif
1200 if (forkshell(jp, cmd, mode) != 0)
1201 goto parent; /* at end of routine */
1202 CTRACE(DBG_PROCS|DBG_CMDS, ("Child sets EV_EXIT\n"));
1203 flags |= EV_EXIT;
1204 FORCEINTON;
1205 #ifdef DO_SHAREDVFORK
1206 }
1207 #endif
1208 if (flags & EV_BACKCMD) {
1209 if (!vforked) {
1210 FORCEINTON;
1211 }
1212 close(pip[0]);
1213 movefd(pip[1], 1);
1214 }
1215 flags |= EV_EXIT;
1216 }
1217
1218 /* This is the child process if a fork occurred. */
1219 /* Execute the command. */
1220 switch (cmdentry.cmdtype) {
1221 volatile int saved;
1222 struct funcdef * volatile savefunc;
1223
1224 case CMDFUNCTION:
1225 VXTRACE(DBG_EVAL, ("Shell function%s: ",vforked?" VF":""),
1226 trargs(argv));
1227 redirect(cmd->ncmd.redirect, saved =
1228 !(flags & EV_EXIT) || have_traps() ? REDIR_PUSH : 0);
1229 saveparam = shellparam;
1230 shellparam.malloc = 0;
1231 shellparam.reset = 1;
1232 shellparam.nparam = argc - 1;
1233 shellparam.p = argv + 1;
1234 shellparam.optnext = NULL;
1235 INTOFF;
1236 savelocalvars = localvars;
1237 localvars = NULL;
1238 reffunc(savefunc = cmdentry.u.func);
1239 INTON;
1240 if (setjmp(jmploc.loc)) {
1241 if (exception == EXSHELLPROC) {
1242 freeparam((volatile struct shparam *)
1243 &saveparam);
1244 } else {
1245 freeparam(&shellparam);
1246 shellparam = saveparam;
1247 }
1248 if (saved)
1249 popredir();
1250 unreffunc(savefunc);
1251 poplocalvars();
1252 localvars = savelocalvars;
1253 funclinebase = savefuncline;
1254 funclineabs = savefuncabs;
1255 handler = savehandler;
1256 longjmp(handler->loc, 1);
1257 }
1258 savehandler = handler;
1259 handler = &jmploc;
1260 if (cmdentry.u.func) {
1261 if (cmdentry.lno_frel)
1262 funclinebase = cmdentry.lineno - 1;
1263 else
1264 funclinebase = 0;
1265 funclineabs = cmdentry.lineno;
1266
1267 VTRACE(DBG_EVAL,
1268 ("function: node: %d '%s' # %d%s; funclinebase=%d\n",
1269 getfuncnode(cmdentry.u.func)->type,
1270 NODETYPENAME(getfuncnode(cmdentry.u.func)->type),
1271 cmdentry.lineno, cmdentry.lno_frel?" (=1)":"",
1272 funclinebase));
1273 }
1274 listmklocal(varlist.list, VDOEXPORT | VEXPORT);
1275 /* stop shell blowing its stack */
1276 if (++funcnest > 1000)
1277 error("too many nested function calls");
1278 evaltree(getfuncnode(cmdentry.u.func),
1279 flags & (EV_TESTED|EV_EXIT));
1280 funcnest--;
1281 INTOFF;
1282 unreffunc(cmdentry.u.func);
1283 poplocalvars();
1284 localvars = savelocalvars;
1285 funclinebase = savefuncline;
1286 funclineabs = savefuncabs;
1287 freeparam(&shellparam);
1288 shellparam = saveparam;
1289 handler = savehandler;
1290 if (saved)
1291 popredir();
1292 INTON;
1293 if (evalskip == SKIPFUNC) {
1294 evalskip = SKIPNONE;
1295 skipcount = 0;
1296 }
1297 if (flags & EV_EXIT)
1298 exitshell(exitstatus);
1299 break;
1300
1301 case CMDSPLBLTIN:
1302 VTRACE(DBG_EVAL, ("special "));
1303 case CMDBUILTIN:
1304 VXTRACE(DBG_EVAL, ("builtin command [%d]%s: ", argc,
1305 vforked ? " VF" : ""), trargs(argv));
1306 mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
1307 if (flags == EV_BACKCMD) {
1308 memout.nleft = 0;
1309 memout.nextc = memout.buf;
1310 memout.bufsize = 64;
1311 mode |= REDIR_BACKQ;
1312 }
1313 e = -1;
1314 savecmdname = commandname;
1315 savetopfile = getcurrentfile();
1316 savehandler = handler;
1317 temp_path = 0;
1318 if (!setjmp(jmploc.loc)) {
1319 handler = &jmploc;
1320
1321 /*
1322 * We need to ensure the command hash table isn't
1323 * corrupted by temporary PATH assignments.
1324 * However we must ensure the 'local' command works!
1325 */
1326 if (path != pathval() && (cmdentry.u.bltin == hashcmd ||
1327 cmdentry.u.bltin == typecmd)) {
1328 savelocalvars = localvars;
1329 localvars = 0;
1330 temp_path = 1;
1331 mklocal(path - 5 /* PATH= */, 0);
1332 }
1333 redirect(cmd->ncmd.redirect, mode);
1334
1335 /*
1336 * the empty command is regarded as a normal
1337 * builtin for the purposes of redirects, but
1338 * is a special builtin for var assigns.
1339 * (unless we are the "command" command.)
1340 */
1341 if (argc == 0 && !(cmd_flags & DO_NOFUNC))
1342 cmdentry.cmdtype = CMDSPLBLTIN;
1343
1344 /* exec is a special builtin, but needs this list... */
1345 cmdenviron = varlist.list;
1346 /* we must check 'readonly' flag for all builtins */
1347 listsetvar(varlist.list,
1348 cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
1349 commandname = argv[0];
1350 /* initialize nextopt */
1351 argptr = argv + 1;
1352 optptr = NULL;
1353 /* and getopt */
1354 optreset = 1;
1355 optind = 1;
1356 builtin_flags = flags;
1357 clr_err(out1); /* discard previous I/O errors */
1358 exitstatus = cmdentry.u.bltin(argc, argv);
1359 } else {
1360 e = exception;
1361 if (e == EXINT)
1362 exitstatus = SIGINT + 128;
1363 else if (e == EXEXEC)
1364 exitstatus = exerrno;
1365 else if (e != EXEXIT)
1366 exitstatus = 2;
1367 }
1368 handler = savehandler;
1369 flushall();
1370 out1 = &output;
1371 out2 = &errout;
1372 freestdout();
1373 if (temp_path) {
1374 poplocalvars();
1375 localvars = savelocalvars;
1376 }
1377 cmdenviron = NULL;
1378 if (e != EXSHELLPROC) {
1379 commandname = savecmdname;
1380 if (flags & EV_EXIT)
1381 exitshell(exitstatus);
1382 }
1383 if (e != -1) {
1384 if ((e != EXERROR && e != EXEXEC)
1385 || cmdentry.cmdtype == CMDSPLBLTIN)
1386 exraise(e);
1387 popfilesupto(savetopfile);
1388 FORCEINTON;
1389 }
1390 if (cmdentry.u.bltin != execcmd)
1391 popredir();
1392 if (flags == EV_BACKCMD) {
1393 backcmd->buf = memout.buf;
1394 backcmd->nleft = memout.nextc - memout.buf;
1395 memout.buf = NULL;
1396 }
1397 break;
1398
1399 default:
1400 VXTRACE(DBG_EVAL, ("normal command%s: ", vforked?" VF":""),
1401 trargs(argv));
1402 redirect(cmd->ncmd.redirect,
1403 (vforked ? REDIR_VFORK : 0) | REDIR_KEEP);
1404 if (!vforked)
1405 for (sp = varlist.list ; sp ; sp = sp->next)
1406 setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK);
1407 envp = environment();
1408 shellexec(argv, envp, path, cmdentry.u.index, vforked);
1409 break;
1410 }
1411 goto out;
1412
1413 parent: /* parent process gets here (if we forked) */
1414
1415 exitstatus = 0; /* if not altered just below */
1416 if (mode == FORK_FG) { /* argument to fork */
1417 exitstatus = waitforjob(jp);
1418 } else if (mode == FORK_NOJOB) {
1419 backcmd->fd = pip[0];
1420 close(pip[1]);
1421 backcmd->jp = jp;
1422 }
1423 FORCEINTON;
1424
1425 out:
1426 if (lastarg)
1427 /* implement $_ for whatever use that really is */
1428 (void) setvarsafe("_", lastarg, VNOERROR);
1429 popstackmark(&smark);
1430 }
1431
1432
1433 /*
1434 * Search for a command. This is called before we fork so that the
1435 * location of the command will be available in the parent as well as
1436 * the child. The check for "goodname" is an overly conservative
1437 * check that the name will not be subject to expansion.
1438 */
1439
1440 STATIC void
1441 prehash(union node *n)
1442 {
1443 struct cmdentry entry;
1444
1445 if (n && n->type == NCMD && n->ncmd.args)
1446 if (goodname(n->ncmd.args->narg.text))
1447 find_command(n->ncmd.args->narg.text, &entry, 0,
1448 pathval());
1449 }
1450
1451 int
1452 in_function(void)
1453 {
1454 return funcnest;
1455 }
1456
1457 enum skipstate
1458 current_skipstate(void)
1459 {
1460 return evalskip;
1461 }
1462
1463 void
1464 save_skipstate(struct skipsave *p)
1465 {
1466 *p = s_k_i_p;
1467 }
1468
1469 void
1470 restore_skipstate(const struct skipsave *p)
1471 {
1472 s_k_i_p = *p;
1473 }
1474
1475 void
1476 stop_skipping(void)
1477 {
1478 evalskip = SKIPNONE;
1479 skipcount = 0;
1480 }
1481
1482 /*
1483 * Builtin commands. Builtin commands whose functions are closely
1484 * tied to evaluation are implemented here.
1485 */
1486
1487 /*
1488 * No command given.
1489 */
1490
1491 int
1492 bltincmd(int argc, char **argv)
1493 {
1494 /*
1495 * Preserve exitstatus of a previous possible redirection
1496 * as POSIX mandates
1497 */
1498 return back_exitstatus;
1499 }
1500
1501
1502 /*
1503 * Handle break and continue commands. Break, continue, and return are
1504 * all handled by setting the evalskip flag. The evaluation routines
1505 * above all check this flag, and if it is set they start skipping
1506 * commands rather than executing them. The variable skipcount is
1507 * the number of loops to break/continue, or the number of function
1508 * levels to return. (The latter is always 1.) It should probably
1509 * be an error to break out of more loops than exist, but it isn't
1510 * in the standard shell so we don't make it one here.
1511 */
1512
1513 int
1514 breakcmd(int argc, char **argv)
1515 {
1516 int n = argc > 1 ? number(argv[1]) : 1;
1517
1518 if (n <= 0)
1519 error("invalid count: %d", n);
1520 if (n > loopnest)
1521 n = loopnest;
1522 if (n > 0) {
1523 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1524 skipcount = n;
1525 }
1526 return 0;
1527 }
1528
1529 int
1530 dotcmd(int argc, char **argv)
1531 {
1532 exitstatus = 0;
1533
1534 (void) nextopt(NULL); /* ignore a leading "--" */
1535
1536 if (*argptr != NULL) { /* That's what SVR2 does */
1537 char *fullname;
1538 /*
1539 * dot_funcnest needs to be 0 when not in a dotcmd, so it
1540 * cannot be restored with (funcnest + 1).
1541 */
1542 int dot_funcnest_old;
1543 struct stackmark smark;
1544
1545 setstackmark(&smark);
1546 fullname = find_dot_file(*argptr);
1547 setinputfile(fullname, 1);
1548 commandname = fullname;
1549 dot_funcnest_old = dot_funcnest;
1550 dot_funcnest = funcnest + 1;
1551 cmdloop(0);
1552 dot_funcnest = dot_funcnest_old;
1553 popfile();
1554 popstackmark(&smark);
1555 }
1556 return exitstatus;
1557 }
1558
1559 /*
1560 * allow dotfile function nesting to be manipulated
1561 * (for read_profile). This allows profile files to
1562 * be treated as if they were used as '.' commands,
1563 * (approximately) and in particular, for "return" to work.
1564 */
1565 int
1566 set_dot_funcnest(int new)
1567 {
1568 int rv = dot_funcnest;
1569
1570 if (new >= 0)
1571 dot_funcnest = new;
1572
1573 return rv;
1574 }
1575
1576 /*
1577 * Take commands from a file. To be compatible we should do a path
1578 * search for the file, which is necessary to find sub-commands.
1579 */
1580
1581 STATIC char *
1582 find_dot_file(char *basename)
1583 {
1584 char *fullname;
1585 const char *path = pathval();
1586 struct stat statb;
1587
1588 /* don't try this for absolute or relative paths */
1589 if (strchr(basename, '/')) {
1590 if (stat(basename, &statb) == 0) {
1591 if (S_ISDIR(statb.st_mode))
1592 error("%s: is a directory", basename);
1593 if (S_ISBLK(statb.st_mode))
1594 error("%s: is a block device", basename);
1595 return basename;
1596 }
1597 } else while ((fullname = padvance(&path, basename, 1)) != NULL) {
1598 if ((stat(fullname, &statb) == 0)) {
1599 /* weird format is to ease future code... */
1600 if (S_ISDIR(statb.st_mode) || S_ISBLK(statb.st_mode))
1601 ;
1602 #if notyet
1603 else if (unreadable()) {
1604 /*
1605 * testing this via st_mode is ugly to get
1606 * correct (and would ignore ACLs).
1607 * better way is just to open the file.
1608 * But doing that here would (currently)
1609 * mean opening the file twice, which
1610 * might not be safe. So, defer this
1611 * test until code is restructures so
1612 * we can return a fd. Then we also
1613 * get to fix the mem leak just below...
1614 */
1615 }
1616 #endif
1617 else {
1618 /*
1619 * Don't bother freeing here, since
1620 * it will be freed by the caller.
1621 * XXX no it won't - a bug for later.
1622 */
1623 return fullname;
1624 }
1625 }
1626 stunalloc(fullname);
1627 }
1628
1629 /* not found in the PATH */
1630 error("%s: not found", basename);
1631 /* NOTREACHED */
1632 }
1633
1634
1635
1636 /*
1637 * The return command.
1638 *
1639 * Quoth the POSIX standard:
1640 * The return utility shall cause the shell to stop executing the current
1641 * function or dot script. If the shell is not currently executing
1642 * a function or dot script, the results are unspecified.
1643 *
1644 * As for the unspecified part, there seems to be no de-facto standard: bash
1645 * ignores the return with a warning, zsh ignores the return in interactive
1646 * mode but seems to liken it to exit in a script. (checked May 2014)
1647 *
1648 * We choose to silently ignore the return. Older versions of this shell
1649 * set evalskip to SKIPFILE causing the shell to (indirectly) exit. This
1650 * had at least the problem of circumventing the check for stopped jobs,
1651 * which would occur for exit or ^D.
1652 */
1653
1654 int
1655 returncmd(int argc, char **argv)
1656 {
1657 int ret = argc > 1 ? number(argv[1]) : exitstatus;
1658
1659 if ((dot_funcnest == 0 && funcnest)
1660 || (dot_funcnest > 0 && funcnest - (dot_funcnest - 1) > 0)) {
1661 evalskip = SKIPFUNC;
1662 skipcount = 1;
1663 } else if (dot_funcnest > 0) {
1664 evalskip = SKIPFILE;
1665 skipcount = 1;
1666 } else {
1667 /* XXX: should a warning be issued? */
1668 ret = 0;
1669 }
1670
1671 return ret;
1672 }
1673
1674
1675 int
1676 falsecmd(int argc, char **argv)
1677 {
1678 return 1;
1679 }
1680
1681
1682 int
1683 truecmd(int argc, char **argv)
1684 {
1685 return 0;
1686 }
1687
1688
1689 int
1690 execcmd(int argc, char **argv)
1691 {
1692 (void) nextopt(NULL); /* ignore a leading "--" */
1693
1694 if (*argptr) {
1695 struct strlist *sp;
1696
1697 iflag = 0; /* exit on error */
1698 mflag = 0;
1699 optschanged();
1700 for (sp = cmdenviron; sp; sp = sp->next)
1701 setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK);
1702 shellexec(argptr, environment(), pathval(), 0, 0);
1703 }
1704 return 0;
1705 }
1706
1707 static int
1708 conv_time(clock_t ticks, char *seconds, size_t l)
1709 {
1710 static clock_t tpm = 0;
1711 clock_t mins;
1712 int i;
1713
1714 if (!tpm)
1715 tpm = sysconf(_SC_CLK_TCK) * 60;
1716
1717 mins = ticks / tpm;
1718 snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
1719
1720 if (seconds[0] == '6' && seconds[1] == '0') {
1721 /* 59.99995 got rounded up... */
1722 mins++;
1723 strlcpy(seconds, "0.0", l);
1724 return mins;
1725 }
1726
1727 /* suppress trailing zeros */
1728 i = strlen(seconds) - 1;
1729 for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
1730 seconds[i] = 0;
1731 return mins;
1732 }
1733
1734 int
1735 timescmd(int argc, char **argv)
1736 {
1737 struct tms tms;
1738 int u, s, cu, cs;
1739 char us[8], ss[8], cus[8], css[8];
1740
1741 nextopt("");
1742
1743 times(&tms);
1744
1745 u = conv_time(tms.tms_utime, us, sizeof(us));
1746 s = conv_time(tms.tms_stime, ss, sizeof(ss));
1747 cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
1748 cs = conv_time(tms.tms_cstime, css, sizeof(css));
1749
1750 outfmt(out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
1751 u, us, s, ss, cu, cus, cs, css);
1752
1753 return 0;
1754 }
1755