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source: trunk/src/kash/eval.c@ 3136

Last change on this file since 3136 was 3065, checked in by bird, 8 years ago
misc gcc warning fixes
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File size: 29.2 KB

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1	/* $NetBSD: eval.c,v 1.84 2005/06/23 23:05:29 christos 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	#if 0
36	#ifndef lint
37	static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
38	#else
39	__RCSID("$NetBSD: eval.c,v 1.84 2005/06/23 23:05:29 christos Exp $");
40	#endif /* not lint */
41	#endif
42
43	#include <stdlib.h>
44	#include <stdio.h>
45	#include <sys/types.h>
46	#ifdef HAVE_SYSCTL_H
47	# ifdef __OpenBSD__ /* joyful crap */
48	# include <sys/param.h>
49	# undef psh
50	# endif
51	# include <sys/sysctl.h>
52	#endif
53
54	/*
55	* Evaluate a command.
56	*/
57
58	#include "shell.h"
59	#include "nodes.h"
60	#include "syntax.h"
61	#include "expand.h"
62	#include "parser.h"
63	#include "jobs.h"
64	#include "eval.h"
65	#include "builtins.h"
66	#include "options.h"
67	#include "exec.h"
68	#include "redir.h"
69	#include "input.h"
70	#include "output.h"
71	#include "trap.h"
72	#include "var.h"
73	#include "memalloc.h"
74	#include "error.h"
75	#include "show.h"
76	#include "mystring.h"
77	#include "main.h"
78	#ifndef SMALL
79	# include "myhistedit.h"
80	#endif
81	#include "shinstance.h"
82
83
84	/* flags in argument to evaltree */
85	#define EV_EXIT 01 /* exit after evaluating tree */
86	#define EV_TESTED 02 /* exit status is checked; ignore -e flag */
87	#define EV_BACKCMD 04 /* command executing within back quotes */
88
89	/int evalskip;/ /* set if we are skipping commands */
90	/STATIC int skipcount;/ /* number of levels to skip */
91	/MKINIT int loopnest;/ /* current loop nesting level */
92	/int funcnest;/ /* depth of function calls */
93
94
95	/char commandname;*/
96	/struct strlist cmdenviron;*/
97	/int exitstatus;/ /* exit status of last command */
98	/int back_exitstatus;/ /* exit status of backquoted command */
99
100
101	STATIC void evalloop(shinstance , union node , int);
102	STATIC void evalfor(shinstance , union node , int);
103	STATIC void evalcase(shinstance , union node , int);
104	STATIC void evalsubshell(shinstance , union node , int);
105	STATIC void expredir(shinstance , union node );
106	STATIC void evalpipe(shinstance , union node );
107	STATIC void evalcommand(shinstance , union node , int, struct backcmd *);
108	STATIC void prehash(shinstance , union node );
109
110
111	/*
112	* Called to reset things after an exception.
113	*/
114
115	#ifdef mkinit
116	INCLUDE "eval.h"
117
118	RESET {
119	psh->evalskip = 0;
120	psh->loopnest = 0;
121	psh->funcnest = 0;
122	}
123
124	SHELLPROC {
125	psh->exitstatus = 0;
126	}
127	#endif
128
129	static int
130	sh_pipe(shinstance *psh, int fds[2])
131	{
132	int nfd;
133
134	if (shfile_pipe(&psh->fdtab, fds))
135	return -1;
136
137	if (fds[0] < 3) {
138	nfd = shfile_fcntl(&psh->fdtab, fds[0], F_DUPFD, 3);
139	if (nfd != -1) {
140	shfile_close(&psh->fdtab, fds[0]);
141	fds[0] = nfd;
142	}
143	}
144
145	if (fds[1] < 3) {
146	nfd = shfile_fcntl(&psh->fdtab, fds[1], F_DUPFD, 3);
147	if (nfd != -1) {
148	shfile_close(&psh->fdtab, fds[1]);
149	fds[1] = nfd;
150	}
151	}
152	return 0;
153	}
154
155
156	/*
157	* The eval commmand.
158	*/
159
160	int
161	evalcmd(shinstance psh, int argc, char *argv)
162	{
163	char *p;
164	char *concat;
165	char **ap;
166
167	if (argc > 1) {
168	p = argv[1];
169	if (argc > 2) {
170	STARTSTACKSTR(psh, concat);
171	ap = argv + 2;
172	for (;;) {
173	while (*p)
174	STPUTC(psh, *p++, concat);
175	if ((p = *ap++) == NULL)
176	break;
177	STPUTC(psh, ' ', concat);
178	}
179	STPUTC(psh, '\0', concat);
180	p = grabstackstr(psh, concat);
181	}
182	evalstring(psh, p, EV_TESTED);
183	}
184	return psh->exitstatus;
185	}
186
187
188	/*
189	* Execute a command or commands contained in a string.
190	*/
191
192	void
193	evalstring(shinstance psh, char s, int flag)
194	{
195	union node *n;
196	struct stackmark smark;
197
198	setstackmark(psh, &smark);
199	setinputstring(psh, s, 1);
200
201	while ((n = parsecmd(psh, 0)) != NEOF) {
202	evaltree(psh, n, flag);
203	popstackmark(psh, &smark);
204	}
205	popfile(psh);
206	popstackmark(psh, &smark);
207	}
208
209
210
211	/*
212	* Evaluate a parse tree. The value is left in the global variable
213	* exitstatus.
214	*/
215
216	void
217	evaltree(shinstance psh, union node n, int flags)
218	{
219	if (n == NULL) {
220	TRACE((psh, "evaltree(NULL) called\n"));
221	psh->exitstatus = 0;
222	goto out;
223	}
224	#ifndef SMALL
225	psh->displayhist = 1; /* show history substitutions done with fc */
226	#endif
227	TRACE((psh, "pid %d, evaltree(%p: %d, %d) called\n",
228	sh_getpid(psh), n, n->type, flags));
229	switch (n->type) {
230	case NSEMI:
231	evaltree(psh, n->nbinary.ch1, flags & EV_TESTED);
232	if (psh->evalskip)
233	goto out;
234	evaltree(psh, n->nbinary.ch2, flags);
235	break;
236	case NAND:
237	evaltree(psh, n->nbinary.ch1, EV_TESTED);
238	if (psh->evalskip \|\| psh->exitstatus != 0)
239	goto out;
240	evaltree(psh, n->nbinary.ch2, flags);
241	break;
242	case NOR:
243	evaltree(psh, n->nbinary.ch1, EV_TESTED);
244	if (psh->evalskip \|\| psh->exitstatus == 0)
245	goto out;
246	evaltree(psh, n->nbinary.ch2, flags);
247	break;
248	case NREDIR:
249	expredir(psh, n->nredir.redirect);
250	redirect(psh, n->nredir.redirect, REDIR_PUSH);
251	evaltree(psh, n->nredir.n, flags);
252	popredir(psh);
253	break;
254	case NSUBSHELL:
255	evalsubshell(psh, n, flags);
256	break;
257	case NBACKGND:
258	evalsubshell(psh, n, flags);
259	break;
260	case NIF: {
261	evaltree(psh, n->nif.test, EV_TESTED);
262	if (psh->evalskip)
263	goto out;
264	if (psh->exitstatus == 0)
265	evaltree(psh, n->nif.ifpart, flags);
266	else if (n->nif.elsepart)
267	evaltree(psh, n->nif.elsepart, flags);
268	else
269	psh->exitstatus = 0;
270	break;
271	}
272	case NWHILE:
273	case NUNTIL:
274	evalloop(psh, n, flags);
275	break;
276	case NFOR:
277	evalfor(psh, n, flags);
278	break;
279	case NCASE:
280	evalcase(psh, n, flags);
281	break;
282	case NDEFUN:
283	defun(psh, n->narg.text, n->narg.next);
284	psh->exitstatus = 0;
285	break;
286	case NNOT:
287	evaltree(psh, n->nnot.com, EV_TESTED);
288	psh->exitstatus = !psh->exitstatus;
289	break;
290	case NPIPE:
291	evalpipe(psh, n);
292	break;
293	case NCMD:
294	evalcommand(psh, n, flags, (struct backcmd *)NULL);
295	break;
296	default:
297	out1fmt(psh, "Node type = %d\n", n->type);
298	flushout(&psh->output);
299	break;
300	}
301	out:
302	if (psh->pendingsigs)
303	dotrap(psh);
304	if ((flags & EV_EXIT) != 0)
305	exitshell(psh, psh->exitstatus);
306	}
307
308
309	STATIC void
310	evalloop(shinstance psh, union node n, int flags)
311	{
312	int status;
313
314	psh->loopnest++;
315	status = 0;
316	for (;;) {
317	evaltree(psh, n->nbinary.ch1, EV_TESTED);
318	if (psh->evalskip) {
319	skipping: if (psh->evalskip == SKIPCONT && --psh->skipcount <= 0) {
320	psh->evalskip = 0;
321	continue;
322	}
323	if (psh->evalskip == SKIPBREAK && --psh->skipcount <= 0)
324	psh->evalskip = 0;
325	break;
326	}
327	if (n->type == NWHILE) {
328	if (psh->exitstatus != 0)
329	break;
330	} else {
331	if (psh->exitstatus == 0)
332	break;
333	}
334	evaltree(psh, n->nbinary.ch2, flags & EV_TESTED);
335	status = psh->exitstatus;
336	if (psh->evalskip)
337	goto skipping;
338	}
339	psh->loopnest--;
340	psh->exitstatus = status;
341	}
342
343
344
345	STATIC void
346	evalfor(shinstance psh, union node n, int flags)
347	{
348	struct arglist arglist;
349	union node *argp;
350	struct strlist *sp;
351	struct stackmark smark;
352	int status = 0;
353
354	setstackmark(psh, &smark);
355	arglist.lastp = &arglist.list;
356	for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
357	expandarg(psh, argp, &arglist, EXP_FULL \| EXP_TILDE);
358	if (psh->evalskip)
359	goto out;
360	}
361	*arglist.lastp = NULL;
362
363	psh->loopnest++;
364	for (sp = arglist.list ; sp ; sp = sp->next) {
365	setvar(psh, n->nfor.var, sp->text, 0);
366	evaltree(psh, n->nfor.body, flags & EV_TESTED);
367	status = psh->exitstatus;
368	if (psh->evalskip) {
369	if (psh->evalskip == SKIPCONT && --psh->skipcount <= 0) {
370	psh->evalskip = 0;
371	continue;
372	}
373	if (psh->evalskip == SKIPBREAK && --psh->skipcount <= 0)
374	psh->evalskip = 0;
375	break;
376	}
377	}
378	psh->loopnest--;
379	psh->exitstatus = status;
380	out:
381	popstackmark(psh, &smark);
382	}
383
384
385
386	STATIC void
387	evalcase(shinstance psh, union node n, int flags)
388	{
389	union node *cp;
390	union node *patp;
391	struct arglist arglist;
392	struct stackmark smark;
393	int status = 0;
394
395	setstackmark(psh, &smark);
396	arglist.lastp = &arglist.list;
397	expandarg(psh, n->ncase.expr, &arglist, EXP_TILDE);
398	for (cp = n->ncase.cases ; cp && psh->evalskip == 0 ; cp = cp->nclist.next) {
399	for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
400	if (casematch(psh, patp, arglist.list->text)) {
401	if (psh->evalskip == 0) {
402	evaltree(psh, cp->nclist.body, flags);
403	status = psh->exitstatus;
404	}
405	goto out;
406	}
407	}
408	}
409	out:
410	psh->exitstatus = status;
411	popstackmark(psh, &smark);
412	}
413
414
415
416	/*
417	* Kick off a subshell to evaluate a tree.
418	*/
419
420	STATIC void
421	evalsubshell(shinstance psh, union node n, int flags)
422	{
423	struct job *jp;
424	int backgnd = (n->type == NBACKGND);
425
426	expredir(psh, n->nredir.redirect);
427	INTOFF;
428	jp = makejob(psh, n, 1);
429	if (forkshell(psh, jp, n, backgnd ? FORK_BG : FORK_FG) == 0) {
430	INTON;
431	if (backgnd)
432	flags &=~ EV_TESTED;
433	redirect(psh, n->nredir.redirect, 0);
434	/* never returns */
435	evaltree(psh, n->nredir.n, flags \| EV_EXIT);
436	}
437	if (! backgnd)
438	psh->exitstatus = waitforjob(psh, jp);
439	INTON;
440	}
441
442
443
444	/*
445	* Compute the names of the files in a redirection list.
446	*/
447
448	STATIC void
449	expredir(shinstance psh, union node n)
450	{
451	union node *redir;
452
453	for (redir = n ; redir ; redir = redir->nfile.next) {
454	struct arglist fn;
455	fn.lastp = &fn.list;
456	switch (redir->type) {
457	case NFROMTO:
458	case NFROM:
459	case NTO:
460	case NCLOBBER:
461	case NAPPEND:
462	expandarg(psh, redir->nfile.fname, &fn, EXP_TILDE \| EXP_REDIR);
463	redir->nfile.expfname = fn.list->text;
464	break;
465	case NFROMFD:
466	case NTOFD:
467	if (redir->ndup.vname) {
468	expandarg(psh, redir->ndup.vname, &fn, EXP_FULL \| EXP_TILDE);
469	fixredir(psh, redir, fn.list->text, 1);
470	}
471	break;
472	}
473	}
474	}
475
476
477
478	/*
479	* Evaluate a pipeline. All the processes in the pipeline are children
480	* of the process creating the pipeline. (This differs from some versions
481	* of the shell, which make the last process in a pipeline the parent
482	* of all the rest.)
483	*/
484
485	STATIC void
486	evalpipe(shinstance psh, union node n)
487	{
488	struct job *jp;
489	struct nodelist *lp;
490	int pipelen;
491	int prevfd;
492	int pip[2];
493
494	TRACE((psh, "evalpipe(0x%lx) called\n", (long)n));
495	pipelen = 0;
496	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
497	pipelen++;
498	INTOFF;
499	jp = makejob(psh, n, pipelen);
500	prevfd = -1;
501	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
502	prehash(psh, lp->n);
503	pip[1] = -1;
504	if (lp->next) {
505	if (sh_pipe(psh, pip) < 0) {
506	shfile_close(&psh->fdtab, prevfd);
507	error(psh, "Pipe call failed");
508	}
509	}
510	if (forkshell(psh, jp, lp->n, n->npipe.backgnd ? FORK_BG : FORK_FG) == 0) {
511	INTON;
512	if (prevfd > 0) {
513	movefd(psh, prevfd, 0);
514	}
515	if (pip[1] >= 0) {
516	shfile_close(&psh->fdtab, pip[0]);
517	if (pip[1] != 1) {
518	movefd(psh, pip[1], 1);
519	}
520	}
521	evaltree(psh, lp->n, EV_EXIT);
522	}
523	if (prevfd >= 0)
524	shfile_close(&psh->fdtab, prevfd);
525	prevfd = pip[0];
526	shfile_close(&psh->fdtab, pip[1]);
527	}
528	if (n->npipe.backgnd == 0) {
529	psh->exitstatus = waitforjob(psh, jp);
530	TRACE((psh, "evalpipe: job done exit status %d\n", psh->exitstatus));
531	}
532	INTON;
533	}
534
535
536
537	/*
538	* Execute a command inside back quotes. If it's a builtin command, we
539	* want to save its output in a block obtained from malloc. Otherwise
540	* we fork off a subprocess and get the output of the command via a pipe.
541	* Should be called with interrupts off.
542	*/
543
544	void
545	evalbackcmd(shinstance psh, union node n, struct backcmd *result)
546	{
547	int pip[2];
548	struct job *jp;
549	struct stackmark smark; /* unnecessary */
550
551	setstackmark(psh, &smark);
552	result->fd = -1;
553	result->buf = NULL;
554	result->nleft = 0;
555	result->jp = NULL;
556	if (n == NULL) {
557	goto out;
558	}
559	#ifdef notyet
560	/*
561	* For now we disable executing builtins in the same
562	* context as the shell, because we are not keeping
563	* enough state to recover from changes that are
564	* supposed only to affect subshells. eg. echo "`cd /`"
565	*/
566	if (n->type == NCMD) {
567	psh->exitstatus = opsh->exitstatus;
568	evalcommand(psh, n, EV_BACKCMD, result);
569	} else
570	#endif
571	{
572	INTOFF;
573	if (sh_pipe(psh, pip) < 0)
574	error(psh, "Pipe call failed");
575	jp = makejob(psh, n, 1);
576	if (forkshell(psh, jp, n, FORK_NOJOB) == 0) {
577	FORCEINTON;
578	shfile_close(&psh->fdtab, pip[0]);
579	if (pip[1] != 1) {
580	movefd(psh, pip[1], 1);
581	}
582	eflag(psh) = 0;
583	evaltree(psh, n, EV_EXIT);
584	/* NOTREACHED */
585	}
586	shfile_close(&psh->fdtab, pip[1]);
587	result->fd = pip[0];
588	result->jp = jp;
589	INTON;
590	}
591	out:
592	popstackmark(psh, &smark);
593	TRACE((psh, "evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
594	result->fd, result->buf, result->nleft, result->jp));
595	}
596
597	static const char *
598	syspath(shinstance *psh)
599	{
600	#ifdef CTL_USER
601	static char *sys_path = NULL;
602	static int mib[] = {CTL_USER, USER_CS_PATH};
603	#endif
604	#ifdef PC_PATH_SEP
605	static char def_path[] = "PATH=/usr/bin;/bin;/usr/sbin;/sbin";
606	#else
607	static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin";
608	#endif
609	#ifdef CTL_USER
610	size_t len;
611
612	if (sys_path == NULL) {
613	if (sysctl(mib, 2, 0, &len, 0, 0) != -1 &&
614	(sys_path = ckmalloc(psh, len + 5)) != NULL &&
615	sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) {
616	memcpy(sys_path, "PATH=", 5);
617	} else {
618	ckfree(psh, sys_path);
619	/* something to keep things happy */
620	sys_path = def_path;
621	}
622	}
623	return sys_path;
624	#else
625	return def_path;
626	#endif
627	}
628
629	static int
630	parse_command_args(shinstance psh, int argc, char argv, int use_syspath)
631	{
632	int sv_argc = argc;
633	char *cp, c;
634
635	*use_syspath = 0;
636
637	for (;;) {
638	argv++;
639	if (--argc == 0)
640	break;
641	cp = *argv;
642	if (*cp++ != '-')
643	break;
644	if (*cp == '-' && cp[1] == 0) {
645	argv++;
646	argc--;
647	break;
648	}
649	while ((c = *cp++)) {
650	switch (c) {
651	case 'p':
652	*use_syspath = 1;
653	break;
654	default:
655	/* run 'typecmd' for other options */
656	return 0;
657	}
658	}
659	}
660	return sv_argc - argc;
661	}
662
663	/int vforked = 0;/
664
665	/*
666	* Execute a simple command.
667	*/
668
669	STATIC void
670	evalcommand(shinstance psh, union node cmd, int flags, struct backcmd *backcmd)
671	{
672	struct stackmark smark;
673	union node *argp;
674	struct arglist arglist;
675	struct arglist varlist;
676	char **argv;
677	int argc;
678	char **envp;
679	int numvars;
680	struct strlist *sp;
681	int mode = 0;
682	int pip[2];
683	struct cmdentry cmdentry;
684	struct job *jp;
685	struct jmploc jmploc;
686	struct jmploc *volatile savehandler;
687	char *volatile savecmdname;
688	volatile struct shparam saveparam;
689	struct localvar *volatile savelocalvars;
690	volatile int e;
691	char *lastarg;
692	const char *path = pathval(psh);
693	volatile int temp_path;
694	#if __GNUC__
695	/* Try avoid longjmp clobbering */
696	(void) &argv;
697	(void) &argc;
698	(void) &lastarg;
699	(void) &flags;
700	(void) &path;
701	(void) &mode;
702	#endif
703
704	psh->vforked = 0;
705	/* First expand the arguments. */
706	TRACE((psh, "evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
707	setstackmark(psh, &smark);
708	psh->back_exitstatus = 0;
709
710	arglist.lastp = &arglist.list;
711	/* Expand arguments, ignoring the initial 'name=value' ones */
712	for (argp = cmd->ncmd.args, numvars = 0 ; argp ; argp = argp->narg.next, numvars++) {
713	char *p = argp->narg.text;
714	char ch = *p;
715	if (is_name(ch)) {
716	do ch = *++p;
717	while (is_in_name(ch));
718	if (ch == '=')
719	continue;
720	}
721	break;
722	}
723	for (/continue on argp from above. / ; argp ; argp = argp->narg.next)
724	expandarg(psh, argp, &arglist, EXP_FULL \| EXP_TILDE);
725	*arglist.lastp = NULL;
726
727	expredir(psh, cmd->ncmd.redirect);
728
729	/* Now do the initial 'name=value' ones we skipped above */
730	varlist.lastp = &varlist.list;
731	for (argp = cmd->ncmd.args ; numvars > 0 && argp ; argp = argp->narg.next, numvars--)
732	expandarg(psh, argp, &varlist, EXP_VARTILDE);
733	*varlist.lastp = NULL;
734
735	argc = 0;
736	for (sp = arglist.list ; sp ; sp = sp->next)
737	argc++;
738	argv = stalloc(psh, sizeof (char ) (argc + 1));
739
740	for (sp = arglist.list ; sp ; sp = sp->next) {
741	TRACE((psh, "evalcommand arg: %s\n", sp->text));
742	*argv++ = sp->text;
743	}
744	*argv = NULL;
745	lastarg = NULL;
746	if (iflag(psh) && psh->funcnest == 0 && argc > 0)
747	lastarg = argv[-1];
748	argv -= argc;
749
750	/* Print the command if xflag is set. */
751	if (xflag(psh)) {
752	char sep = 0;
753	out2str(psh, ps4val(psh));
754	for (sp = varlist.list ; sp ; sp = sp->next) {
755	if (sep != 0)
756	outc(sep, &psh->errout);
757	out2str(psh, sp->text);
758	sep = ' ';
759	}
760	for (sp = arglist.list ; sp ; sp = sp->next) {
761	if (sep != 0)
762	outc(sep, &psh->errout);
763	out2str(psh, sp->text);
764	sep = ' ';
765	}
766	outc('\n', &psh->errout);
767	flushout(&psh->errout);
768	}
769
770	/* Now locate the command. */
771	if (argc == 0) {
772	cmdentry.cmdtype = CMDSPLBLTIN;
773	cmdentry.u.bltin = bltincmd;
774	} else {
775	static const char PATH[] = "PATH=";
776	int cmd_flags = DO_ERR;
777
778	/*
779	* Modify the command lookup path, if a PATH= assignment
780	* is present
781	*/
782	for (sp = varlist.list; sp; sp = sp->next)
783	if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
784	path = sp->text + sizeof(PATH) - 1;
785
786	do {
787	int argsused, use_syspath;
788	find_command(psh, argv[0], &cmdentry, cmd_flags, path);
789	if (cmdentry.cmdtype == CMDUNKNOWN) {
790	psh->exitstatus = 127;
791	flushout(&psh->errout);
792	goto out;
793	}
794
795	/* implement the 'command' builtin here */
796	if (cmdentry.cmdtype != CMDBUILTIN \|\|
797	cmdentry.u.bltin != bltincmd)
798	break;
799	cmd_flags \|= DO_NOFUNC;
800	argsused = parse_command_args(psh, argc, argv, &use_syspath);
801	if (argsused == 0) {
802	/* use 'type' builting to display info */
803	cmdentry.u.bltin = typecmd;
804	break;
805	}
806	argc -= argsused;
807	argv += argsused;
808	if (use_syspath)
809	path = syspath(psh) + 5;
810	} while (argc != 0);
811	if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
812	/* posix mandates that 'command <splbltin>' act as if
813	<splbltin> was a normal builtin */
814	cmdentry.cmdtype = CMDBUILTIN;
815	}
816
817	/* Fork off a child process if necessary. */
818	if (cmd->ncmd.backgnd
819	\|\| (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
820	\|\| ((flags & EV_BACKCMD) != 0
821	&& ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN)
822	\|\| cmdentry.u.bltin == dotcmd
823	\|\| cmdentry.u.bltin == evalcmd))) {
824	INTOFF;
825	jp = makejob(psh, cmd, 1);
826	mode = cmd->ncmd.backgnd;
827	if (flags & EV_BACKCMD) {
828	mode = FORK_NOJOB;
829	if (sh_pipe(psh, pip) < 0)
830	error(psh, "Pipe call failed");
831	}
832	#ifdef DO_SHAREDVFORK
833	/* It is essential that if DO_SHAREDVFORK is defined that the
834	* child's address space is actually shared with the parent as
835	* we rely on this.
836	*/
837	if (cmdentry.cmdtype == CMDNORMAL) {
838	pid_t pid;
839
840	savelocalvars = psh->localvars;
841	psh->localvars = NULL;
842	psh->vforked = 1;
843	switch (pid = vfork()) {
844	case -1:
845	TRACE((psh, "Vfork failed, errno=%d\n", errno));
846	INTON;
847	error(psh, "Cannot vfork");
848	break;
849	case 0:
850	/* Make sure that exceptions only unwind to
851	* after the vfork(2)
852	*/
853	if (setjmp(jmploc.loc)) {
854	if (psh->exception == EXSHELLPROC) {
855	/* We can't progress with the vfork,
856	* so, set vforked = 2 so the parent
857	* knows, and _exit();
858	*/
859	psh->vforked = 2;
860	sh__exit(psh, 0);
861	} else {
862	sh__exit(psh, psh->exerrno);
863	}
864	}
865	savehandler = psh->handler;
866	psh->handler = &jmploc;
867	listmklocal(psh, varlist.list, VEXPORT \| VNOFUNC);
868	forkchild(psh, jp, cmd, mode, psh->vforked);
869	break;
870	default:
871	psh->handler = savehandler; /* restore from vfork(2) */
872	poplocalvars(psh);
873	psh->localvars = savelocalvars;
874	if (psh->vforked == 2) {
875	psh->vforked = 0;
876
877	(void)sh_waitpid(psh, pid, NULL, 0);
878	/* We need to progress in a normal fork fashion */
879	goto normal_fork;
880	}
881	psh->vforked = 0;
882	forkparent(psh, jp, cmd, mode, pid);
883	goto parent;
884	}
885	} else {
886	normal_fork:
887	#endif
888	if (forkshell(psh, jp, cmd, mode) != 0)
889	goto parent; /* at end of routine */
890	FORCEINTON;
891	#ifdef DO_SHAREDVFORK
892	}
893	#endif
894	if (flags & EV_BACKCMD) {
895	if (!psh->vforked) {
896	FORCEINTON;
897	}
898	shfile_close(&psh->fdtab, pip[0]);
899	if (pip[1] != 1) {
900	movefd(psh, pip[1], 1);
901	}
902	}
903	flags \|= EV_EXIT;
904	}
905
906	/* This is the child process if a fork occurred. */
907	/* Execute the command. */
908	switch (cmdentry.cmdtype) {
909	case CMDFUNCTION:
910	#ifdef DEBUG
911	trputs(psh, "Shell function: "); trargs(psh, argv);
912	#endif
913	redirect(psh, cmd->ncmd.redirect, REDIR_PUSH);
914	saveparam = psh->shellparam;
915	psh->shellparam.malloc = 0;
916	psh->shellparam.reset = 1;
917	psh->shellparam.nparam = argc - 1;
918	psh->shellparam.p = argv + 1;
919	psh->shellparam.optnext = NULL;
920	INTOFF;
921	savelocalvars = psh->localvars;
922	psh->localvars = NULL;
923	INTON;
924	if (setjmp(jmploc.loc)) {
925	if (psh->exception == EXSHELLPROC) {
926	freeparam(psh, (volatile struct shparam *)
927	&saveparam);
928	} else {
929	freeparam(psh, &psh->shellparam);
930	psh->shellparam = saveparam;
931	}
932	poplocalvars(psh);
933	psh->localvars = savelocalvars;
934	psh->handler = savehandler;
935	longjmp(psh->handler->loc, 1);
936	}
937	savehandler = psh->handler;
938	psh->handler = &jmploc;
939	listmklocal(psh, varlist.list, 0);
940	/* stop shell blowing its stack */
941	if (++psh->funcnest > 1000)
942	error(psh, "too many nested function calls");
943	evaltree(psh, cmdentry.u.func, flags & EV_TESTED);
944	psh->funcnest--;
945	INTOFF;
946	poplocalvars(psh);
947	psh->localvars = savelocalvars;
948	freeparam(psh, &psh->shellparam);
949	psh->shellparam = saveparam;
950	psh->handler = savehandler;
951	popredir(psh);
952	INTON;
953	if (psh->evalskip == SKIPFUNC) {
954	psh->evalskip = 0;
955	psh->skipcount = 0;
956	}
957	if (flags & EV_EXIT)
958	exitshell(psh, psh->exitstatus);
959	break;
960
961	case CMDBUILTIN:
962	case CMDSPLBLTIN:
963	#ifdef DEBUG
964	trputs(psh, "builtin command: "); trargs(psh, argv);
965	#endif
966	mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
967	if (flags == EV_BACKCMD) {
968	psh->memout.nleft = 0;
969	psh->memout.nextc = psh->memout.buf;
970	psh->memout.bufsize = 64;
971	mode \|= REDIR_BACKQ;
972	}
973	e = -1;
974	savehandler = psh->handler;
975	savecmdname = psh->commandname;
976	psh->handler = &jmploc;
977	if (!setjmp(jmploc.loc)) {
978	/* We need to ensure the command hash table isn't
979	* corruped by temporary PATH assignments.
980	* However we must ensure the 'local' command works!
981	*/
982	if (path != pathval(psh) && (cmdentry.u.bltin == hashcmd \|\|
983	cmdentry.u.bltin == typecmd)) {
984	savelocalvars = psh->localvars;
985	psh->localvars = 0;
986	mklocal(psh, path - 5 /* PATH= */, 0);
987	temp_path = 1;
988	} else
989	temp_path = 0;
990	redirect(psh, cmd->ncmd.redirect, mode);
991
992	/* exec is a special builtin, but needs this list... */
993	psh->cmdenviron = varlist.list;
994	/* we must check 'readonly' flag for all builtins */
995	listsetvar(psh, varlist.list,
996	cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
997	psh->commandname = argv[0];
998	/* initialize nextopt */
999	psh->argptr = argv + 1;
1000	psh->optptr = NULL;
1001	/* and getopt */
1002	#if 0 /** @todo fix getop usage! */
1003	#if defined(__FreeBSD__) \|\| defined(__EMX__) \|\| defined(__APPLE__)
1004	optreset = 1;
1005	optind = 1;
1006	#else
1007	optind = 0; /* init */
1008	#endif
1009	#endif
1010
1011	psh->exitstatus = cmdentry.u.bltin(psh, argc, argv);
1012	} else {
1013	e = psh->exception;
1014	psh->exitstatus = e == EXINT ? SIGINT + 128 :
1015	e == EXEXEC ? psh->exerrno : 2;
1016	}
1017	psh->handler = savehandler;
1018	output_flushall(psh);
1019	psh->out1 = &psh->output;
1020	psh->out2 = &psh->errout;
1021	freestdout(psh);
1022	if (temp_path) {
1023	poplocalvars(psh);
1024	psh->localvars = savelocalvars;
1025	}
1026	psh->cmdenviron = NULL;
1027	if (e != EXSHELLPROC) {
1028	psh->commandname = savecmdname;
1029	if (flags & EV_EXIT)
1030	exitshell(psh, psh->exitstatus);
1031	}
1032	if (e != -1) {
1033	if ((e != EXERROR && e != EXEXEC)
1034	\|\| cmdentry.cmdtype == CMDSPLBLTIN)
1035	exraise(psh, e);
1036	FORCEINTON;
1037	}
1038	if (cmdentry.u.bltin != execcmd)
1039	popredir(psh);
1040	if (flags == EV_BACKCMD) {
1041	backcmd->buf = psh->memout.buf;
1042	backcmd->nleft = (int)(psh->memout.nextc - psh->memout.buf);
1043	psh->memout.buf = NULL;
1044	}
1045	break;
1046
1047	default:
1048	#ifdef DEBUG
1049	trputs(psh, "normal command: "); trargs(psh, argv);
1050	#endif
1051	clearredir(psh, psh->vforked);
1052	redirect(psh, cmd->ncmd.redirect, psh->vforked ? REDIR_VFORK : 0);
1053	if (!psh->vforked)
1054	for (sp = varlist.list ; sp ; sp = sp->next)
1055	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1056	envp = environment(psh);
1057	shellexec(psh, argv, envp, path, cmdentry.u.index, psh->vforked);
1058	break;
1059	}
1060	goto out;
1061
1062	parent: /* parent process gets here (if we forked) */
1063	if (mode == FORK_FG) { /* argument to fork */
1064	psh->exitstatus = waitforjob(psh, jp);
1065	} else if (mode == FORK_NOJOB) {
1066	backcmd->fd = pip[0];
1067	shfile_close(&psh->fdtab, pip[1]);
1068	backcmd->jp = jp;
1069	}
1070	FORCEINTON;
1071
1072	out:
1073	if (lastarg)
1074	/* dsl: I think this is intended to be used to support
1075	* '_' in 'vi' command mode during line editing...
1076	* However I implemented that within libedit itself.
1077	*/
1078	setvar(psh, "_", lastarg, 0);
1079	popstackmark(psh, &smark);
1080
1081	if (eflag(psh) && psh->exitstatus && !(flags & EV_TESTED))
1082	exitshell(psh, psh->exitstatus);
1083	}
1084
1085
1086	/*
1087	* Search for a command. This is called before we fork so that the
1088	* location of the command will be available in the parent as well as
1089	* the child. The check for "goodname" is an overly conservative
1090	* check that the name will not be subject to expansion.
1091	*/
1092
1093	STATIC void
1094	prehash(shinstance psh, union node n)
1095	{
1096	struct cmdentry entry;
1097
1098	if (n->type == NCMD && n->ncmd.args)
1099	if (goodname(n->ncmd.args->narg.text))
1100	find_command(psh, n->ncmd.args->narg.text, &entry, 0,
1101	pathval(psh));
1102	}
1103
1104
1105
1106	/*
1107	* Builtin commands. Builtin commands whose functions are closely
1108	* tied to evaluation are implemented here.
1109	*/
1110
1111	/*
1112	* No command given.
1113	*/
1114
1115	int
1116	bltincmd(shinstance psh, int argc, char *argv)
1117	{
1118	/*
1119	* Preserve psh->exitstatus of a previous possible redirection
1120	* as POSIX mandates
1121	*/
1122	return psh->back_exitstatus;
1123	}
1124
1125
1126	/*
1127	* Handle break and continue commands. Break, continue, and return are
1128	* all handled by setting the psh->evalskip flag. The evaluation routines
1129	* above all check this flag, and if it is set they start skipping
1130	* commands rather than executing them. The variable skipcount is
1131	* the number of loops to break/continue, or the number of function
1132	* levels to return. (The latter is always 1.) It should probably
1133	* be an error to break out of more loops than exist, but it isn't
1134	* in the standard shell so we don't make it one here.
1135	*/
1136
1137	int
1138	breakcmd(shinstance psh, int argc, char *argv)
1139	{
1140	int n = argc > 1 ? number(psh, argv[1]) : 1;
1141
1142	if (n > psh->loopnest)
1143	n = psh->loopnest;
1144	if (n > 0) {
1145	psh->evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1146	psh->skipcount = n;
1147	}
1148	return 0;
1149	}
1150
1151
1152	/*
1153	* The return command.
1154	*/
1155
1156	int
1157	returncmd(shinstance psh, int argc, char *argv)
1158	{
1159	#if 0
1160	int ret = argc > 1 ? number(psh, argv[1]) : psh->exitstatus;
1161	#else
1162	int ret;
1163	if (argc > 1) {
1164	/* make return -1 and VSC lite work ... */
1165	if (argv[1][0] != '-' \|\| !is_number(&argv[1][1]))
1166	ret = number(psh, argv[1]);
1167	else
1168	ret = -number(psh, &argv[1][1]) & 255; /* take the bash approach */
1169	} else {
1170	ret = psh->exitstatus;
1171	}
1172	#endif
1173
1174	if (psh->funcnest) {
1175	psh->evalskip = SKIPFUNC;
1176	psh->skipcount = 1;
1177	return ret;
1178	}
1179	else {
1180	/* Do what ksh does; skip the rest of the file */
1181	psh->evalskip = SKIPFILE;
1182	psh->skipcount = 1;
1183	return ret;
1184	}
1185	}
1186
1187
1188	int
1189	falsecmd(shinstance psh, int argc, char *argv)
1190	{
1191	return 1;
1192	}
1193
1194
1195	int
1196	truecmd(shinstance psh, int argc, char *argv)
1197	{
1198	return 0;
1199	}
1200
1201
1202	int
1203	execcmd(shinstance psh, int argc, char *argv)
1204	{
1205	if (argc > 1) {
1206	struct strlist *sp;
1207
1208	iflag(psh) = 0; /* exit on error */
1209	mflag(psh) = 0;
1210	optschanged(psh);
1211	for (sp = psh->cmdenviron; sp; sp = sp->next)
1212	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1213	shellexec(psh, argv + 1, environment(psh), pathval(psh), 0, 0);
1214	}
1215	return 0;
1216	}
1217
1218	static int
1219	conv_time(clock_t ticks, char *seconds, size_t l)
1220	{
1221	static clock_t tpm = 0;
1222	clock_t mins;
1223	size_t i;
1224
1225	if (!tpm)
1226	tpm = /sysconf(_SC_CLK_TCK)/sh_sysconf_clk_tck() * 60;
1227
1228	mins = ticks / tpm;
1229	#ifdef _MSC_VER
1230	{
1231	char tmp[64];
1232	sprintf(tmp, "%.4f", (ticks - mins * tpm) * 60.0 / tpm);
1233	strlcpy(seconds, tmp, l);
1234	}
1235	#else
1236	snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
1237	#endif
1238
1239	if (seconds[0] == '6' && seconds[1] == '0') {
1240	/* 59.99995 got rounded up... */
1241	mins++;
1242	strlcpy(seconds, "0.0", l);
1243	return mins;
1244	}
1245
1246	/* suppress trailing zeros */
1247	i = strlen(seconds) - 1;
1248	for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
1249	seconds[i] = 0;
1250	return mins;
1251	}
1252
1253	int
1254	timescmd(shinstance psh, int argc, char *argv)
1255	{
1256	shtms tms;
1257	int u, s, cu, cs;
1258	char us[8], ss[8], cus[8], css[8];
1259
1260	nextopt(psh, "");
1261
1262	sh_times(psh, &tms);
1263
1264	u = conv_time(tms.tms_utime, us, sizeof(us));
1265	s = conv_time(tms.tms_stime, ss, sizeof(ss));
1266	cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
1267	cs = conv_time(tms.tms_cstime, css, sizeof(css));
1268
1269	outfmt(psh->out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
1270	u, us, s, ss, cu, cus, cs, css);
1271
1272	return 0;
1273	}

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