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source: trunk/src/kash/eval.c@ 2653

Last change on this file since 2653 was 2653, checked in by bird, 13 years ago
kash: fixed shfile_opendir on windows, and thereby argument expansion.
Property svn:eol-style set to `LF` Property svn:keywords set to `Id`
File size: 29.4 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 varflag;
680	struct strlist *sp;
681	int mode;
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	/* Avoid longjmp clobbering */
696	(void) &argv;
697	(void) &argc;
698	(void) &lastarg;
699	(void) &flags;
700	#endif
701
702	psh->vforked = 0;
703	/* First expand the arguments. */
704	TRACE((psh, "evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
705	setstackmark(psh, &smark);
706	psh->back_exitstatus = 0;
707
708	/** @todo r=bird: Why is arguments and envvars expanded in this
709	* particular order? It would be both faster and simpler to do the
710	* envvars first and then continue with the arguments... */
711	arglist.lastp = &arglist.list;
712	varflag = 1;
713	/* Expand arguments, ignoring the initial 'name=value' ones */
714	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
715	char *p = argp->narg.text;
716	if (varflag && is_name(*p)) {
717	do {
718	p++;
719	} while (is_in_name(*p));
720	if (*p == '=')
721	continue;
722	}
723	expandarg(psh, argp, &arglist, EXP_FULL \| EXP_TILDE);
724	varflag = 0;
725	}
726	*arglist.lastp = NULL;
727
728	expredir(psh, cmd->ncmd.redirect);
729
730	/* Now do the initial 'name=value' ones we skipped above */
731	varlist.lastp = &varlist.list;
732	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
733	char *p = argp->narg.text;
734	if (!is_name(*p))
735	break;
736	do
737	p++;
738	while (is_in_name(*p));
739	if (*p != '=')
740	break;
741	expandarg(psh, argp, &varlist, EXP_VARTILDE);
742	}
743	*varlist.lastp = NULL;
744
745	argc = 0;
746	for (sp = arglist.list ; sp ; sp = sp->next)
747	argc++;
748	argv = stalloc(psh, sizeof (char ) (argc + 1));
749
750	for (sp = arglist.list ; sp ; sp = sp->next) {
751	TRACE((psh, "evalcommand arg: %s\n", sp->text));
752	*argv++ = sp->text;
753	}
754	*argv = NULL;
755	lastarg = NULL;
756	if (iflag(psh) && psh->funcnest == 0 && argc > 0)
757	lastarg = argv[-1];
758	argv -= argc;
759
760	/* Print the command if xflag is set. */
761	if (xflag(psh)) {
762	char sep = 0;
763	out2str(psh, ps4val(psh));
764	for (sp = varlist.list ; sp ; sp = sp->next) {
765	if (sep != 0)
766	outc(sep, &psh->errout);
767	out2str(psh, sp->text);
768	sep = ' ';
769	}
770	for (sp = arglist.list ; sp ; sp = sp->next) {
771	if (sep != 0)
772	outc(sep, &psh->errout);
773	out2str(psh, sp->text);
774	sep = ' ';
775	}
776	outc('\n', &psh->errout);
777	flushout(&psh->errout);
778	}
779
780	/* Now locate the command. */
781	if (argc == 0) {
782	cmdentry.cmdtype = CMDSPLBLTIN;
783	cmdentry.u.bltin = bltincmd;
784	} else {
785	static const char PATH[] = "PATH=";
786	int cmd_flags = DO_ERR;
787
788	/*
789	* Modify the command lookup path, if a PATH= assignment
790	* is present
791	*/
792	for (sp = varlist.list; sp; sp = sp->next)
793	if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
794	path = sp->text + sizeof(PATH) - 1;
795
796	do {
797	int argsused, use_syspath;
798	find_command(psh, argv[0], &cmdentry, cmd_flags, path);
799	if (cmdentry.cmdtype == CMDUNKNOWN) {
800	psh->exitstatus = 127;
801	flushout(&psh->errout);
802	goto out;
803	}
804
805	/* implement the 'command' builtin here */
806	if (cmdentry.cmdtype != CMDBUILTIN \|\|
807	cmdentry.u.bltin != bltincmd)
808	break;
809	cmd_flags \|= DO_NOFUNC;
810	argsused = parse_command_args(psh, argc, argv, &use_syspath);
811	if (argsused == 0) {
812	/* use 'type' builting to display info */
813	cmdentry.u.bltin = typecmd;
814	break;
815	}
816	argc -= argsused;
817	argv += argsused;
818	if (use_syspath)
819	path = syspath(psh) + 5;
820	} while (argc != 0);
821	if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
822	/* posix mandates that 'command <splbltin>' act as if
823	<splbltin> was a normal builtin */
824	cmdentry.cmdtype = CMDBUILTIN;
825	}
826
827	/* Fork off a child process if necessary. */
828	if (cmd->ncmd.backgnd
829	\|\| (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
830	\|\| ((flags & EV_BACKCMD) != 0
831	&& ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN)
832	\|\| cmdentry.u.bltin == dotcmd
833	\|\| cmdentry.u.bltin == evalcmd))) {
834	INTOFF;
835	jp = makejob(psh, cmd, 1);
836	mode = cmd->ncmd.backgnd;
837	if (flags & EV_BACKCMD) {
838	mode = FORK_NOJOB;
839	if (sh_pipe(psh, pip) < 0)
840	error(psh, "Pipe call failed");
841	}
842	#ifdef DO_SHAREDVFORK
843	/* It is essential that if DO_SHAREDVFORK is defined that the
844	* child's address space is actually shared with the parent as
845	* we rely on this.
846	*/
847	if (cmdentry.cmdtype == CMDNORMAL) {
848	pid_t pid;
849
850	savelocalvars = psh->localvars;
851	psh->localvars = NULL;
852	psh->vforked = 1;
853	switch (pid = vfork()) {
854	case -1:
855	TRACE((psh, "Vfork failed, errno=%d\n", errno));
856	INTON;
857	error(psh, "Cannot vfork");
858	break;
859	case 0:
860	/* Make sure that exceptions only unwind to
861	* after the vfork(2)
862	*/
863	if (setjmp(jmploc.loc)) {
864	if (psh->exception == EXSHELLPROC) {
865	/* We can't progress with the vfork,
866	* so, set vforked = 2 so the parent
867	* knows, and _exit();
868	*/
869	psh->vforked = 2;
870	sh__exit(psh, 0);
871	} else {
872	sh__exit(psh, psh->exerrno);
873	}
874	}
875	savehandler = psh->handler;
876	psh->handler = &jmploc;
877	listmklocal(psh, varlist.list, VEXPORT \| VNOFUNC);
878	forkchild(psh, jp, cmd, mode, psh->vforked);
879	break;
880	default:
881	psh->handler = savehandler; /* restore from vfork(2) */
882	poplocalvars(psh);
883	psh->localvars = savelocalvars;
884	if (psh->vforked == 2) {
885	psh->vforked = 0;
886
887	(void)sh_waitpid(psh, pid, NULL, 0);
888	/* We need to progress in a normal fork fashion */
889	goto normal_fork;
890	}
891	psh->vforked = 0;
892	forkparent(psh, jp, cmd, mode, pid);
893	goto parent;
894	}
895	} else {
896	normal_fork:
897	#endif
898	if (forkshell(psh, jp, cmd, mode) != 0)
899	goto parent; /* at end of routine */
900	FORCEINTON;
901	#ifdef DO_SHAREDVFORK
902	}
903	#endif
904	if (flags & EV_BACKCMD) {
905	if (!psh->vforked) {
906	FORCEINTON;
907	}
908	shfile_close(&psh->fdtab, pip[0]);
909	if (pip[1] != 1) {
910	movefd(psh, pip[1], 1);
911	}
912	}
913	flags \|= EV_EXIT;
914	}
915
916	/* This is the child process if a fork occurred. */
917	/* Execute the command. */
918	switch (cmdentry.cmdtype) {
919	case CMDFUNCTION:
920	#ifdef DEBUG
921	trputs(psh, "Shell function: "); trargs(psh, argv);
922	#endif
923	redirect(psh, cmd->ncmd.redirect, REDIR_PUSH);
924	saveparam = psh->shellparam;
925	psh->shellparam.malloc = 0;
926	psh->shellparam.reset = 1;
927	psh->shellparam.nparam = argc - 1;
928	psh->shellparam.p = argv + 1;
929	psh->shellparam.optnext = NULL;
930	INTOFF;
931	savelocalvars = psh->localvars;
932	psh->localvars = NULL;
933	INTON;
934	if (setjmp(jmploc.loc)) {
935	if (psh->exception == EXSHELLPROC) {
936	freeparam(psh, (volatile struct shparam *)
937	&saveparam);
938	} else {
939	freeparam(psh, &psh->shellparam);
940	psh->shellparam = saveparam;
941	}
942	poplocalvars(psh);
943	psh->localvars = savelocalvars;
944	psh->handler = savehandler;
945	longjmp(psh->handler->loc, 1);
946	}
947	savehandler = psh->handler;
948	psh->handler = &jmploc;
949	listmklocal(psh, varlist.list, 0);
950	/* stop shell blowing its stack */
951	if (++psh->funcnest > 1000)
952	error(psh, "too many nested function calls");
953	evaltree(psh, cmdentry.u.func, flags & EV_TESTED);
954	psh->funcnest--;
955	INTOFF;
956	poplocalvars(psh);
957	psh->localvars = savelocalvars;
958	freeparam(psh, &psh->shellparam);
959	psh->shellparam = saveparam;
960	psh->handler = savehandler;
961	popredir(psh);
962	INTON;
963	if (psh->evalskip == SKIPFUNC) {
964	psh->evalskip = 0;
965	psh->skipcount = 0;
966	}
967	if (flags & EV_EXIT)
968	exitshell(psh, psh->exitstatus);
969	break;
970
971	case CMDBUILTIN:
972	case CMDSPLBLTIN:
973	#ifdef DEBUG
974	trputs(psh, "builtin command: "); trargs(psh, argv);
975	#endif
976	mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
977	if (flags == EV_BACKCMD) {
978	psh->memout.nleft = 0;
979	psh->memout.nextc = psh->memout.buf;
980	psh->memout.bufsize = 64;
981	mode \|= REDIR_BACKQ;
982	}
983	e = -1;
984	savehandler = psh->handler;
985	savecmdname = psh->commandname;
986	psh->handler = &jmploc;
987	if (!setjmp(jmploc.loc)) {
988	/* We need to ensure the command hash table isn't
989	* corruped by temporary PATH assignments.
990	* However we must ensure the 'local' command works!
991	*/
992	if (path != pathval(psh) && (cmdentry.u.bltin == hashcmd \|\|
993	cmdentry.u.bltin == typecmd)) {
994	savelocalvars = psh->localvars;
995	psh->localvars = 0;
996	mklocal(psh, path - 5 /* PATH= */, 0);
997	temp_path = 1;
998	} else
999	temp_path = 0;
1000	redirect(psh, cmd->ncmd.redirect, mode);
1001
1002	/* exec is a special builtin, but needs this list... */
1003	psh->cmdenviron = varlist.list;
1004	/* we must check 'readonly' flag for all builtins */
1005	listsetvar(psh, varlist.list,
1006	cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
1007	psh->commandname = argv[0];
1008	/* initialize nextopt */
1009	psh->argptr = argv + 1;
1010	psh->optptr = NULL;
1011	/* and getopt */
1012	#if 0 /** @todo fix getop usage! */
1013	#if defined(__FreeBSD__) \|\| defined(__EMX__) \|\| defined(__APPLE__)
1014	optreset = 1;
1015	optind = 1;
1016	#else
1017	optind = 0; /* init */
1018	#endif
1019	#endif
1020
1021	psh->exitstatus = cmdentry.u.bltin(psh, argc, argv);
1022	} else {
1023	e = psh->exception;
1024	psh->exitstatus = e == EXINT ? SIGINT + 128 :
1025	e == EXEXEC ? psh->exerrno : 2;
1026	}
1027	psh->handler = savehandler;
1028	output_flushall(psh);
1029	psh->out1 = &psh->output;
1030	psh->out2 = &psh->errout;
1031	freestdout(psh);
1032	if (temp_path) {
1033	poplocalvars(psh);
1034	psh->localvars = savelocalvars;
1035	}
1036	psh->cmdenviron = NULL;
1037	if (e != EXSHELLPROC) {
1038	psh->commandname = savecmdname;
1039	if (flags & EV_EXIT)
1040	exitshell(psh, psh->exitstatus);
1041	}
1042	if (e != -1) {
1043	if ((e != EXERROR && e != EXEXEC)
1044	\|\| cmdentry.cmdtype == CMDSPLBLTIN)
1045	exraise(psh, e);
1046	FORCEINTON;
1047	}
1048	if (cmdentry.u.bltin != execcmd)
1049	popredir(psh);
1050	if (flags == EV_BACKCMD) {
1051	backcmd->buf = psh->memout.buf;
1052	backcmd->nleft = (int)(psh->memout.nextc - psh->memout.buf);
1053	psh->memout.buf = NULL;
1054	}
1055	break;
1056
1057	default:
1058	#ifdef DEBUG
1059	trputs(psh, "normal command: "); trargs(psh, argv);
1060	#endif
1061	clearredir(psh, psh->vforked);
1062	redirect(psh, cmd->ncmd.redirect, psh->vforked ? REDIR_VFORK : 0);
1063	if (!psh->vforked)
1064	for (sp = varlist.list ; sp ; sp = sp->next)
1065	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1066	envp = environment(psh);
1067	shellexec(psh, argv, envp, path, cmdentry.u.index, psh->vforked);
1068	break;
1069	}
1070	goto out;
1071
1072	parent: /* parent process gets here (if we forked) */
1073	if (mode == FORK_FG) { /* argument to fork */
1074	psh->exitstatus = waitforjob(psh, jp);
1075	} else if (mode == FORK_NOJOB) {
1076	backcmd->fd = pip[0];
1077	shfile_close(&psh->fdtab, pip[1]);
1078	backcmd->jp = jp;
1079	}
1080	FORCEINTON;
1081
1082	out:
1083	if (lastarg)
1084	/* dsl: I think this is intended to be used to support
1085	* '_' in 'vi' command mode during line editing...
1086	* However I implemented that within libedit itself.
1087	*/
1088	setvar(psh, "_", lastarg, 0);
1089	popstackmark(psh, &smark);
1090
1091	if (eflag(psh) && psh->exitstatus && !(flags & EV_TESTED))
1092	exitshell(psh, psh->exitstatus);
1093	}
1094
1095
1096	/*
1097	* Search for a command. This is called before we fork so that the
1098	* location of the command will be available in the parent as well as
1099	* the child. The check for "goodname" is an overly conservative
1100	* check that the name will not be subject to expansion.
1101	*/
1102
1103	STATIC void
1104	prehash(shinstance psh, union node n)
1105	{
1106	struct cmdentry entry;
1107
1108	if (n->type == NCMD && n->ncmd.args)
1109	if (goodname(n->ncmd.args->narg.text))
1110	find_command(psh, n->ncmd.args->narg.text, &entry, 0,
1111	pathval(psh));
1112	}
1113
1114
1115
1116	/*
1117	* Builtin commands. Builtin commands whose functions are closely
1118	* tied to evaluation are implemented here.
1119	*/
1120
1121	/*
1122	* No command given.
1123	*/
1124
1125	int
1126	bltincmd(shinstance psh, int argc, char *argv)
1127	{
1128	/*
1129	* Preserve psh->exitstatus of a previous possible redirection
1130	* as POSIX mandates
1131	*/
1132	return psh->back_exitstatus;
1133	}
1134
1135
1136	/*
1137	* Handle break and continue commands. Break, continue, and return are
1138	* all handled by setting the psh->evalskip flag. The evaluation routines
1139	* above all check this flag, and if it is set they start skipping
1140	* commands rather than executing them. The variable skipcount is
1141	* the number of loops to break/continue, or the number of function
1142	* levels to return. (The latter is always 1.) It should probably
1143	* be an error to break out of more loops than exist, but it isn't
1144	* in the standard shell so we don't make it one here.
1145	*/
1146
1147	int
1148	breakcmd(shinstance psh, int argc, char *argv)
1149	{
1150	int n = argc > 1 ? number(psh, argv[1]) : 1;
1151
1152	if (n > psh->loopnest)
1153	n = psh->loopnest;
1154	if (n > 0) {
1155	psh->evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1156	psh->skipcount = n;
1157	}
1158	return 0;
1159	}
1160
1161
1162	/*
1163	* The return command.
1164	*/
1165
1166	int
1167	returncmd(shinstance psh, int argc, char *argv)
1168	{
1169	#if 0
1170	int ret = argc > 1 ? number(psh, argv[1]) : psh->exitstatus;
1171	#else
1172	int ret;
1173	if (argc > 1) {
1174	/* make return -1 and VSC lite work ... */
1175	if (argv[1][0] != '-' \|\| !is_number(&argv[1][1]))
1176	ret = number(psh, argv[1]);
1177	else
1178	ret = -number(psh, &argv[1][1]) & 255; /* take the bash approach */
1179	} else {
1180	ret = psh->exitstatus;
1181	}
1182	#endif
1183
1184	if (psh->funcnest) {
1185	psh->evalskip = SKIPFUNC;
1186	psh->skipcount = 1;
1187	return ret;
1188	}
1189	else {
1190	/* Do what ksh does; skip the rest of the file */
1191	psh->evalskip = SKIPFILE;
1192	psh->skipcount = 1;
1193	return ret;
1194	}
1195	}
1196
1197
1198	int
1199	falsecmd(shinstance psh, int argc, char *argv)
1200	{
1201	return 1;
1202	}
1203
1204
1205	int
1206	truecmd(shinstance psh, int argc, char *argv)
1207	{
1208	return 0;
1209	}
1210
1211
1212	int
1213	execcmd(shinstance psh, int argc, char *argv)
1214	{
1215	if (argc > 1) {
1216	struct strlist *sp;
1217
1218	iflag(psh) = 0; /* exit on error */
1219	mflag(psh) = 0;
1220	optschanged(psh);
1221	for (sp = psh->cmdenviron; sp; sp = sp->next)
1222	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1223	shellexec(psh, argv + 1, environment(psh), pathval(psh), 0, 0);
1224	}
1225	return 0;
1226	}
1227
1228	static int
1229	conv_time(clock_t ticks, char *seconds, size_t l)
1230	{
1231	static clock_t tpm = 0;
1232	clock_t mins;
1233	size_t i;
1234
1235	if (!tpm)
1236	tpm = /sysconf(_SC_CLK_TCK)/sh_sysconf_clk_tck() * 60;
1237
1238	mins = ticks / tpm;
1239	#ifdef _MSC_VER
1240	{
1241	char tmp[64];
1242	sprintf(tmp, "%.4f", (ticks - mins * tpm) * 60.0 / tpm);
1243	strlcpy(seconds, tmp, l);
1244	}
1245	#else
1246	snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
1247	#endif
1248
1249	if (seconds[0] == '6' && seconds[1] == '0') {
1250	/* 59.99995 got rounded up... */
1251	mins++;
1252	strlcpy(seconds, "0.0", l);
1253	return mins;
1254	}
1255
1256	/* suppress trailing zeros */
1257	i = strlen(seconds) - 1;
1258	for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
1259	seconds[i] = 0;
1260	return mins;
1261	}
1262
1263	int
1264	timescmd(shinstance psh, int argc, char *argv)
1265	{
1266	shtms tms;
1267	int u, s, cu, cs;
1268	char us[8], ss[8], cus[8], css[8];
1269
1270	nextopt(psh, "");
1271
1272	sh_times(psh, &tms);
1273
1274	u = conv_time(tms.tms_utime, us, sizeof(us));
1275	s = conv_time(tms.tms_stime, ss, sizeof(ss));
1276	cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
1277	cs = conv_time(tms.tms_cstime, css, sizeof(css));
1278
1279	outfmt(psh->out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
1280	u, us, s, ss, cu, cus, cs, css);
1281
1282	return 0;
1283	}

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