Context Navigation

eval.c@ 1115

Last change on this file since 1115 was 884, checked in by bird, 19 years ago
hacking...
Property svn:eol-style set to `native`
File size: 29.4 KB

Line
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	#ifdef HAVE_SYS_CDEFS_H
36	#include <sys/cdefs.h>
37	#endif
38	#ifndef lint
39	#if 0
40	static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
41	#else
42	__RCSID("$NetBSD: eval.c,v 1.84 2005/06/23 23:05:29 christos Exp $");
43	#endif
44	#endif /* not lint */
45
46	#include <stdlib.h>
47	#include <signal.h>
48	#include <stdio.h>
49	#include <unistd.h>
50	#include <sys/fcntl.h>
51	#include <sys/times.h>
52	#include <sys/param.h>
53	#include <sys/types.h>
54	#include <sys/wait.h>
55	#ifdef HAVE_SYSCTL_H
56	#include <sys/sysctl.h>
57	#endif
58	#ifdef __sun__
59	#include <iso/limits_iso.h>
60	#endif
61
62	/*
63	* Evaluate a command.
64	*/
65
66	#include "shell.h"
67	#include "nodes.h"
68	#include "syntax.h"
69	#include "expand.h"
70	#include "parser.h"
71	#include "jobs.h"
72	#include "eval.h"
73	#include "builtins.h"
74	#include "options.h"
75	#include "exec.h"
76	#include "redir.h"
77	#include "input.h"
78	#include "output.h"
79	#include "trap.h"
80	#include "var.h"
81	#include "memalloc.h"
82	#include "error.h"
83	#include "show.h"
84	#include "mystring.h"
85	#include "main.h"
86	#ifndef SMALL
87	#include "myhistedit.h"
88	#endif
89	#include "shinstance.h"
90
91
92	/* flags in argument to evaltree */
93	#define EV_EXIT 01 /* exit after evaluating tree */
94	#define EV_TESTED 02 /* exit status is checked; ignore -e flag */
95	#define EV_BACKCMD 04 /* command executing within back quotes */
96
97	/int evalskip;/ /* set if we are skipping commands */
98	/STATIC int skipcount;/ /* number of levels to skip */
99	/MKINIT int loopnest;/ /* current loop nesting level */
100	/int funcnest;/ /* depth of function calls */
101
102
103	/char commandname;*/
104	/struct strlist cmdenviron;*/
105	/int exitstatus;/ /* exit status of last command */
106	/int back_exitstatus;/ /* exit status of backquoted command */
107
108
109	STATIC void evalloop(shinstance , union node , int);
110	STATIC void evalfor(shinstance , union node , int);
111	STATIC void evalcase(shinstance , union node , int);
112	STATIC void evalsubshell(shinstance , union node , int);
113	STATIC void expredir(shinstance , union node );
114	STATIC void evalpipe(shinstance , union node );
115	STATIC void evalcommand(shinstance , union node , int, struct backcmd *);
116	STATIC void prehash(shinstance , union node );
117
118
119	/*
120	* Called to reset things after an exception.
121	*/
122
123	#ifdef mkinit
124	INCLUDE "eval.h"
125
126	RESET {
127	evalskip = 0;
128	loopnest = 0;
129	funcnest = 0;
130	}
131
132	SHELLPROC {
133	exitstatus = 0;
134	}
135	#endif
136
137	static int
138	sh_pipe(shinstance *psh, int fds[2])
139	{
140	int nfd;
141
142	if (shfile_pipe(&psh->fdtab, fds))
143	return -1;
144
145	if (fds[0] < 3) {
146	nfd = shfile_fcntl(&psh->fdtab, fds[0], F_DUPFD, 3);
147	if (nfd != -1) {
148	shfile_close(&psh->fdtab, fds[0]);
149	fds[0] = nfd;
150	}
151	}
152
153	if (fds[1] < 3) {
154	nfd = shfile_fcntl(&psh->fdtab, fds[1], F_DUPFD, 3);
155	if (nfd != -1) {
156	shfile_close(&psh->fdtab, fds[1]);
157	fds[1] = nfd;
158	}
159	}
160	return 0;
161	}
162
163
164	/*
165	* The eval commmand.
166	*/
167
168	int
169	evalcmd(shinstance psh, int argc, char *argv)
170	{
171	char *p;
172	char *concat;
173	char **ap;
174
175	if (argc > 1) {
176	p = argv[1];
177	if (argc > 2) {
178	STARTSTACKSTR(concat);
179	ap = argv + 2;
180	for (;;) {
181	while (*p)
182	STPUTC(*p++, concat);
183	if ((p = *ap++) == NULL)
184	break;
185	STPUTC(' ', concat);
186	}
187	STPUTC('\0', concat);
188	p = grabstackstr(concat);
189	}
190	evalstring(psh, p, EV_TESTED);
191	}
192	return psh->exitstatus;
193	}
194
195
196	/*
197	* Execute a command or commands contained in a string.
198	*/
199
200	void
201	evalstring(shinstance psh, char s, int flag)
202	{
203	union node *n;
204	struct stackmark smark;
205
206	setstackmark(psh, &smark);
207	setinputstring(psh, s, 1);
208
209	while ((n = parsecmd(psh, 0)) != NEOF) {
210	evaltree(psh, n, flag);
211	popstackmark(psh, &smark);
212	}
213	popfile(psh);
214	popstackmark(psh, &smark);
215	}
216
217
218
219	/*
220	* Evaluate a parse tree. The value is left in the global variable
221	* exitstatus.
222	*/
223
224	void
225	evaltree(shinstance psh, union node n, int flags)
226	{
227	if (n == NULL) {
228	TRACE(("evaltree(NULL) called\n"));
229	psh->exitstatus = 0;
230	goto out;
231	}
232	#ifndef SMALL
233	psh->displayhist = 1; /* show history substitutions done with fc */
234	#endif
235	TRACE(("pid %d, evaltree(%p: %d, %d) called\n",
236	getpid(), n, n->type, flags));
237	switch (n->type) {
238	case NSEMI:
239	evaltree(psh, n->nbinary.ch1, flags & EV_TESTED);
240	if (psh->evalskip)
241	goto out;
242	evaltree(psh, n->nbinary.ch2, flags);
243	break;
244	case NAND:
245	evaltree(psh, n->nbinary.ch1, EV_TESTED);
246	if (psh->evalskip \|\| psh->exitstatus != 0)
247	goto out;
248	evaltree(psh, n->nbinary.ch2, flags);
249	break;
250	case NOR:
251	evaltree(psh, n->nbinary.ch1, EV_TESTED);
252	if (psh->evalskip \|\| psh->exitstatus == 0)
253	goto out;
254	evaltree(psh, n->nbinary.ch2, flags);
255	break;
256	case NREDIR:
257	expredir(psh, n->nredir.redirect);
258	redirect(psh, n->nredir.redirect, REDIR_PUSH);
259	evaltree(psh, n->nredir.n, flags);
260	popredir(psh);
261	break;
262	case NSUBSHELL:
263	evalsubshell(psh, n, flags);
264	break;
265	case NBACKGND:
266	evalsubshell(psh, n, flags);
267	break;
268	case NIF: {
269	evaltree(psh, n->nif.test, EV_TESTED);
270	if (psh->evalskip)
271	goto out;
272	if (psh->exitstatus == 0)
273	evaltree(psh, n->nif.ifpart, flags);
274	else if (n->nif.elsepart)
275	evaltree(psh, n->nif.elsepart, flags);
276	else
277	psh->exitstatus = 0;
278	break;
279	}
280	case NWHILE:
281	case NUNTIL:
282	evalloop(psh, n, flags);
283	break;
284	case NFOR:
285	evalfor(psh, n, flags);
286	break;
287	case NCASE:
288	evalcase(psh, n, flags);
289	break;
290	case NDEFUN:
291	defun(psh, n->narg.text, n->narg.next);
292	psh->exitstatus = 0;
293	break;
294	case NNOT:
295	evaltree(psh, n->nnot.com, EV_TESTED);
296	psh->exitstatus = !psh->exitstatus;
297	break;
298	case NPIPE:
299	evalpipe(psh, n);
300	break;
301	case NCMD:
302	evalcommand(psh, n, flags, (struct backcmd *)NULL);
303	break;
304	default:
305	out1fmt(psh, "Node type = %d\n", n->type);
306	flushout(&psh->output);
307	break;
308	}
309	out:
310	if (psh->pendingsigs)
311	dotrap(psh);
312	if ((flags & EV_EXIT) != 0)
313	exitshell(psh, psh->exitstatus);
314	}
315
316
317	STATIC void
318	evalloop(shinstance psh, union node n, int flags)
319	{
320	int status;
321
322	psh->loopnest++;
323	status = 0;
324	for (;;) {
325	evaltree(psh, n->nbinary.ch1, EV_TESTED);
326	if (psh->evalskip) {
327	skipping: if (psh->evalskip == SKIPCONT && --psh->skipcount <= 0) {
328	psh->evalskip = 0;
329	continue;
330	}
331	if (psh->evalskip == SKIPBREAK && --psh->skipcount <= 0)
332	psh->evalskip = 0;
333	break;
334	}
335	if (n->type == NWHILE) {
336	if (psh->exitstatus != 0)
337	break;
338	} else {
339	if (psh->exitstatus == 0)
340	break;
341	}
342	evaltree(psh, n->nbinary.ch2, flags & EV_TESTED);
343	status = psh->exitstatus;
344	if (psh->evalskip)
345	goto skipping;
346	}
347	psh->loopnest--;
348	psh->exitstatus = status;
349	}
350
351
352
353	STATIC void
354	evalfor(shinstance psh, union node n, int flags)
355	{
356	struct arglist arglist;
357	union node *argp;
358	struct strlist *sp;
359	struct stackmark smark;
360	int status = 0;
361
362	setstackmark(psh, &smark);
363	arglist.lastp = &arglist.list;
364	for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
365	expandarg(psh, argp, &arglist, EXP_FULL \| EXP_TILDE);
366	if (psh->evalskip)
367	goto out;
368	}
369	*arglist.lastp = NULL;
370
371	psh->loopnest++;
372	for (sp = arglist.list ; sp ; sp = sp->next) {
373	setvar(psh, n->nfor.var, sp->text, 0);
374	evaltree(psh, n->nfor.body, flags & EV_TESTED);
375	status = psh->exitstatus;
376	if (psh->evalskip) {
377	if (psh->evalskip == SKIPCONT && --psh->skipcount <= 0) {
378	psh->evalskip = 0;
379	continue;
380	}
381	if (psh->evalskip == SKIPBREAK && --psh->skipcount <= 0)
382	psh->evalskip = 0;
383	break;
384	}
385	}
386	psh->loopnest--;
387	psh->exitstatus = status;
388	out:
389	popstackmark(psh, &smark);
390	}
391
392
393
394	STATIC void
395	evalcase(shinstance psh, union node n, int flags)
396	{
397	union node *cp;
398	union node *patp;
399	struct arglist arglist;
400	struct stackmark smark;
401	int status = 0;
402
403	setstackmark(psh, &smark);
404	arglist.lastp = &arglist.list;
405	expandarg(psh, n->ncase.expr, &arglist, EXP_TILDE);
406	for (cp = n->ncase.cases ; cp && psh->evalskip == 0 ; cp = cp->nclist.next) {
407	for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
408	if (casematch(psh, patp, arglist.list->text)) {
409	if (psh->evalskip == 0) {
410	evaltree(psh, cp->nclist.body, flags);
411	status = psh->exitstatus;
412	}
413	goto out;
414	}
415	}
416	}
417	out:
418	psh->exitstatus = status;
419	popstackmark(psh, &smark);
420	}
421
422
423
424	/*
425	* Kick off a subshell to evaluate a tree.
426	*/
427
428	STATIC void
429	evalsubshell(shinstance psh, union node n, int flags)
430	{
431	struct job *jp;
432	int backgnd = (n->type == NBACKGND);
433
434	expredir(psh, n->nredir.redirect);
435	INTOFF;
436	jp = makejob(psh, n, 1);
437	if (forkshell(psh, jp, n, backgnd ? FORK_BG : FORK_FG) == 0) {
438	INTON;
439	if (backgnd)
440	flags &=~ EV_TESTED;
441	redirect(psh, n->nredir.redirect, 0);
442	/* never returns */
443	evaltree(psh, n->nredir.n, flags \| EV_EXIT);
444	}
445	if (! backgnd)
446	psh->exitstatus = waitforjob(psh, jp);
447	INTON;
448	}
449
450
451
452	/*
453	* Compute the names of the files in a redirection list.
454	*/
455
456	STATIC void
457	expredir(shinstance psh, union node n)
458	{
459	union node *redir;
460
461	for (redir = n ; redir ; redir = redir->nfile.next) {
462	struct arglist fn;
463	fn.lastp = &fn.list;
464	switch (redir->type) {
465	case NFROMTO:
466	case NFROM:
467	case NTO:
468	case NCLOBBER:
469	case NAPPEND:
470	expandarg(psh, redir->nfile.fname, &fn, EXP_TILDE \| EXP_REDIR);
471	redir->nfile.expfname = fn.list->text;
472	break;
473	case NFROMFD:
474	case NTOFD:
475	if (redir->ndup.vname) {
476	expandarg(psh, redir->ndup.vname, &fn, EXP_FULL \| EXP_TILDE);
477	fixredir(psh, redir, fn.list->text, 1);
478	}
479	break;
480	}
481	}
482	}
483
484
485
486	/*
487	* Evaluate a pipeline. All the processes in the pipeline are children
488	* of the process creating the pipeline. (This differs from some versions
489	* of the shell, which make the last process in a pipeline the parent
490	* of all the rest.)
491	*/
492
493	STATIC void
494	evalpipe(shinstance psh, union node n)
495	{
496	struct job *jp;
497	struct nodelist *lp;
498	int pipelen;
499	int prevfd;
500	int pip[2];
501
502	TRACE(("evalpipe(0x%lx) called\n", (long)n));
503	pipelen = 0;
504	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
505	pipelen++;
506	INTOFF;
507	jp = makejob(psh, n, pipelen);
508	prevfd = -1;
509	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
510	prehash(psh, lp->n);
511	pip[1] = -1;
512	if (lp->next) {
513	if (sh_pipe(psh, pip) < 0) {
514	shfile_close(&psh->fdtab, prevfd);
515	error(psh, "Pipe call failed");
516	}
517	}
518	if (forkshell(psh, jp, lp->n, n->npipe.backgnd ? FORK_BG : FORK_FG) == 0) {
519	INTON;
520	if (prevfd > 0) {
521	shfile_close(&psh->fdtab, 0);
522	copyfd(psh, prevfd, 0);
523	shfile_close(&psh->fdtab, prevfd);
524	}
525	if (pip[1] >= 0) {
526	shfile_close(&psh->fdtab, pip[0]);
527	if (pip[1] != 1) {
528	shfile_close(&psh->fdtab, 1);
529	copyfd(psh, pip[1], 1);
530	shfile_close(&psh->fdtab, pip[1]);
531	}
532	}
533	evaltree(psh, lp->n, EV_EXIT);
534	}
535	if (prevfd >= 0)
536	shfile_close(&psh->fdtab, prevfd);
537	prevfd = pip[0];
538	shfile_close(&psh->fdtab, pip[1]);
539	}
540	if (n->npipe.backgnd == 0) {
541	psh->exitstatus = waitforjob(psh, jp);
542	TRACE(("evalpipe: job done exit status %d\n", psh->exitstatus));
543	}
544	INTON;
545	}
546
547
548
549	/*
550	* Execute a command inside back quotes. If it's a builtin command, we
551	* want to save its output in a block obtained from malloc. Otherwise
552	* we fork off a subprocess and get the output of the command via a pipe.
553	* Should be called with interrupts off.
554	*/
555
556	void
557	evalbackcmd(shinstance psh, union node n, struct backcmd *result)
558	{
559	int pip[2];
560	struct job *jp;
561	struct stackmark smark; /* unnecessary */
562
563	setstackmark(psh, &smark);
564	result->fd = -1;
565	result->buf = NULL;
566	result->nleft = 0;
567	result->jp = NULL;
568	if (n == NULL) {
569	goto out;
570	}
571	#ifdef notyet
572	/*
573	* For now we disable executing builtins in the same
574	* context as the shell, because we are not keeping
575	* enough state to recover from changes that are
576	* supposed only to affect subshells. eg. echo "`cd /`"
577	*/
578	if (n->type == NCMD) {
579	psh->exitstatus = opsh->exitstatus;
580	evalcommand(psh, n, EV_BACKCMD, result);
581	} else
582	#endif
583	{
584	INTOFF;
585	if (sh_pipe(psh, pip) < 0)
586	error(psh, "Pipe call failed");
587	jp = makejob(psh, n, 1);
588	if (forkshell(psh, jp, n, FORK_NOJOB) == 0) {
589	FORCEINTON;
590	shfile_close(&psh->fdtab, pip[0]);
591	if (pip[1] != 1) {
592	shfile_close(&psh->fdtab, 1);
593	copyfd(psh, pip[1], 1);
594	shfile_close(&psh->fdtab, pip[1]);
595	}
596	psh->eflag = 0;
597	evaltree(psh, n, EV_EXIT);
598	/* NOTREACHED */
599	}
600	shfile_close(&psh->fdtab, pip[1]);
601	result->fd = pip[0];
602	result->jp = jp;
603	INTON;
604	}
605	out:
606	popstackmark(psh, &smark);
607	TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
608	result->fd, result->buf, result->nleft, result->jp));
609	}
610
611	static const char *
612	syspath(shinstance *psh)
613	{
614	#ifdef CTL_USER
615	static char *sys_path = NULL;
616	static int mib[] = {CTL_USER, USER_CS_PATH};
617	#endif
618	#ifdef PC_PATH_SEP
619	static char def_path[] = "PATH=/usr/bin;/bin;/usr/sbin;/sbin";
620	#else
621	static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin";
622	#endif
623	#ifdef CTL_USER
624	size_t len;
625
626	if (sys_path == NULL) {
627	if (sysctl(mib, 2, 0, &len, 0, 0) != -1 &&
628	(sys_path = ckmalloc(len + 5)) != NULL &&
629	sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) {
630	memcpy(sys_path, "PATH=", 5);
631	} else {
632	ckfree(sys_path);
633	/* something to keep things happy */
634	sys_path = def_path;
635	}
636	}
637	return sys_path;
638	#else
639	return def_path;
640	#endif
641	}
642
643	static int
644	parse_command_args(shinstance psh, int argc, char argv, int use_syspath)
645	{
646	int sv_argc = argc;
647	char *cp, c;
648
649	*use_syspath = 0;
650
651	for (;;) {
652	argv++;
653	if (--argc == 0)
654	break;
655	cp = *argv;
656	if (*cp++ != '-')
657	break;
658	if (*cp == '-' && cp[1] == 0) {
659	argv++;
660	argc--;
661	break;
662	}
663	while ((c = *cp++)) {
664	switch (c) {
665	case 'p':
666	*use_syspath = 1;
667	break;
668	default:
669	/* run 'typecmd' for other options */
670	return 0;
671	}
672	}
673	}
674	return sv_argc - argc;
675	}
676
677	/int vforked = 0;/
678
679	/*
680	* Execute a simple command.
681	*/
682
683	STATIC void
684	evalcommand(shinstance psh, union node cmd, int flags, struct backcmd *backcmd)
685	{
686	struct stackmark smark;
687	union node *argp;
688	struct arglist arglist;
689	struct arglist varlist;
690	char **argv;
691	int argc;
692	char **envp;
693	int varflag;
694	struct strlist *sp;
695	int mode;
696	int pip[2];
697	struct cmdentry cmdentry;
698	struct job *jp;
699	struct jmploc jmploc;
700	struct jmploc *volatile savehandler;
701	char *volatile savecmdname;
702	volatile struct shparam saveparam;
703	struct localvar *volatile savelocalvars;
704	volatile int e;
705	char *lastarg;
706	const char *path = pathval(psh);
707	volatile int temp_path;
708	#if __GNUC__
709	/* Avoid longjmp clobbering */
710	(void) &argv;
711	(void) &argc;
712	(void) &lastarg;
713	(void) &flags;
714	#endif
715
716	psh->vforked = 0;
717	/* First expand the arguments. */
718	TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
719	setstackmark(psh, &smark);
720	psh->exitstatus = 0;
721
722	arglist.lastp = &arglist.list;
723	varflag = 1;
724	/* Expand arguments, ignoring the initial 'name=value' ones */
725	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
726	char *p = argp->narg.text;
727	if (varflag && is_name(*p)) {
728	do {
729	p++;
730	} while (is_in_name(*p));
731	if (*p == '=')
732	continue;
733	}
734	expandarg(psh, argp, &arglist, EXP_FULL \| EXP_TILDE);
735	varflag = 0;
736	}
737	*arglist.lastp = NULL;
738
739	expredir(psh, cmd->ncmd.redirect);
740
741	/* Now do the initial 'name=value' ones we skipped above */
742	varlist.lastp = &varlist.list;
743	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
744	char *p = argp->narg.text;
745	if (!is_name(*p))
746	break;
747	do
748	p++;
749	while (is_in_name(*p));
750	if (*p != '=')
751	break;
752	expandarg(psh, argp, &varlist, EXP_VARTILDE);
753	}
754	*varlist.lastp = NULL;
755
756	argc = 0;
757	for (sp = arglist.list ; sp ; sp = sp->next)
758	argc++;
759	argv = stalloc(psh, sizeof (char ) (argc + 1));
760
761	for (sp = arglist.list ; sp ; sp = sp->next) {
762	TRACE(("evalcommand arg: %s\n", sp->text));
763	*argv++ = sp->text;
764	}
765	*argv = NULL;
766	lastarg = NULL;
767	if (psh->iflag && psh->funcnest == 0 && argc > 0)
768	lastarg = argv[-1];
769	argv -= argc;
770
771	/* Print the command if xflag is set. */
772	if (psh->xflag) {
773	char sep = 0;
774	out2str(psh, ps4val(psh));
775	for (sp = varlist.list ; sp ; sp = sp->next) {
776	if (sep != 0)
777	outc(sep, &psh->errout);
778	out2str(psh, sp->text);
779	sep = ' ';
780	}
781	for (sp = arglist.list ; sp ; sp = sp->next) {
782	if (sep != 0)
783	outc(sep, &psh->errout);
784	out2str(psh, sp->text);
785	sep = ' ';
786	}
787	outc('\n', &psh->errout);
788	flushout(&psh->errout);
789	}
790
791	/* Now locate the command. */
792	if (argc == 0) {
793	cmdentry.cmdtype = CMDSPLBLTIN;
794	cmdentry.u.bltin = bltincmd;
795	} else {
796	static const char PATH[] = "PATH=";
797	int cmd_flags = DO_ERR;
798
799	/*
800	* Modify the command lookup path, if a PATH= assignment
801	* is present
802	*/
803	for (sp = varlist.list; sp; sp = sp->next)
804	if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
805	path = sp->text + sizeof(PATH) - 1;
806
807	do {
808	int argsused, use_syspath;
809	find_command(psh, argv[0], &cmdentry, cmd_flags, path);
810	if (cmdentry.cmdtype == CMDUNKNOWN) {
811	psh->exitstatus = 127;
812	flushout(&psh->errout);
813	goto out;
814	}
815
816	/* implement the 'command' builtin here */
817	if (cmdentry.cmdtype != CMDBUILTIN \|\|
818	cmdentry.u.bltin != bltincmd)
819	break;
820	cmd_flags \|= DO_NOFUNC;
821	argsused = parse_command_args(psh, argc, argv, &use_syspath);
822	if (argsused == 0) {
823	/* use 'type' builting to display info */
824	cmdentry.u.bltin = typecmd;
825	break;
826	}
827	argc -= argsused;
828	argv += argsused;
829	if (use_syspath)
830	path = syspath(psh) + 5;
831	} while (argc != 0);
832	if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
833	/* posix mandates that 'command <splbltin>' act as if
834	<splbltin> was a normal builtin */
835	cmdentry.cmdtype = CMDBUILTIN;
836	}
837
838	/* Fork off a child process if necessary. */
839	if (cmd->ncmd.backgnd
840	\|\| (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
841	\|\| ((flags & EV_BACKCMD) != 0
842	&& ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN)
843	\|\| cmdentry.u.bltin == dotcmd
844	\|\| cmdentry.u.bltin == evalcmd))) {
845	INTOFF;
846	jp = makejob(psh, cmd, 1);
847	mode = cmd->ncmd.backgnd;
848	if (flags & EV_BACKCMD) {
849	mode = FORK_NOJOB;
850	if (sh_pipe(psh, pip) < 0)
851	error(psh, "Pipe call failed");
852	}
853	#ifdef DO_SHAREDVFORK
854	/* It is essential that if DO_SHAREDVFORK is defined that the
855	* child's address space is actually shared with the parent as
856	* we rely on this.
857	*/
858	if (cmdentry.cmdtype == CMDNORMAL) {
859	pid_t pid;
860
861	savelocalvars = psh->localvars;
862	psh->localvars = NULL;
863	psh->vforked = 1;
864	switch (pid = vfork()) {
865	case -1:
866	TRACE(("Vfork failed, errno=%d\n", errno));
867	INTON;
868	error(psh, "Cannot vfork");
869	break;
870	case 0:
871	/* Make sure that exceptions only unwind to
872	* after the vfork(2)
873	*/
874	if (setjmp(jmploc.loc)) {
875	if (psh->exception == EXSHELLPROC) {
876	/* We can't progress with the vfork,
877	* so, set vforked = 2 so the parent
878	* knows, and _exit();
879	*/
880	psh->vforked = 2;
881	sh__exit(psh, 0);
882	} else {
883	sh__exit(psh, exerrno);
884	}
885	}
886	savehandler = psh->handler;
887	psh->handler = &jmploc;
888	listmklocal(psh, varlist.list, VEXPORT \| VNOFUNC);
889	forkchild(psh, jp, cmd, mode, psh->vforked);
890	break;
891	default:
892	psh->handler = savehandler; /* restore from vfork(2) */
893	poplocalvars(psh);
894	psh->localvars = savelocalvars;
895	if (psh->vforked == 2) {
896	psh->vforked = 0;
897
898	(void)sh_waitpid(psh, pid, NULL, 0);
899	/* We need to progress in a normal fork fashion */
900	goto normal_fork;
901	}
902	psh->vforked = 0;
903	forkparent(psh, jp, cmd, mode, pid);
904	goto parent;
905	}
906	} else {
907	normal_fork:
908	#endif
909	if (forkshell(psh, jp, cmd, mode) != 0)
910	goto parent; /* at end of routine */
911	FORCEINTON;
912	#ifdef DO_SHAREDVFORK
913	}
914	#endif
915	if (flags & EV_BACKCMD) {
916	if (!psh->vforked) {
917	FORCEINTON;
918	}
919	shfile_close(&psh->fdtab, pip[0]);
920	if (pip[1] != 1) {
921	shfile_close(&psh->fdtab, 1);
922	copyfd(psh, pip[1], 1);
923	shfile_close(&psh->fdtab, pip[1]);
924	}
925	}
926	flags \|= EV_EXIT;
927	}
928
929	/* This is the child process if a fork occurred. */
930	/* Execute the command. */
931	switch (cmdentry.cmdtype) {
932	case CMDFUNCTION:
933	#ifdef DEBUG
934	trputs("Shell function: "); trargs(argv);
935	#endif
936	redirect(psh, cmd->ncmd.redirect, REDIR_PUSH);
937	saveparam = psh->shellparam;
938	psh->shellparam.malloc = 0;
939	psh->shellparam.reset = 1;
940	psh->shellparam.nparam = argc - 1;
941	psh->shellparam.p = argv + 1;
942	psh->shellparam.optnext = NULL;
943	INTOFF;
944	savelocalvars = psh->localvars;
945	psh->localvars = NULL;
946	INTON;
947	if (setjmp(jmploc.loc)) {
948	if (psh->exception == EXSHELLPROC) {
949	freeparam((volatile struct shparam *)
950	&saveparam);
951	} else {
952	freeparam(&psh->shellparam);
953	psh->shellparam = saveparam;
954	}
955	poplocalvars(psh);
956	psh->localvars = savelocalvars;
957	psh->handler = savehandler;
958	longjmp(psh->handler->loc, 1);
959	}
960	savehandler = psh->handler;
961	psh->handler = &jmploc;
962	listmklocal(psh, varlist.list, 0);
963	/* stop shell blowing its stack */
964	if (++psh->funcnest > 1000)
965	error(psh, "too many nested function calls");
966	evaltree(psh, cmdentry.u.func, flags & EV_TESTED);
967	psh->funcnest--;
968	INTOFF;
969	poplocalvars(psh);
970	psh->localvars = savelocalvars;
971	freeparam(&psh->shellparam);
972	psh->shellparam = saveparam;
973	psh->handler = savehandler;
974	popredir(psh);
975	INTON;
976	if (psh->evalskip == SKIPFUNC) {
977	psh->evalskip = 0;
978	psh->skipcount = 0;
979	}
980	if (flags & EV_EXIT)
981	exitshell(psh, psh->exitstatus);
982	break;
983
984	case CMDBUILTIN:
985	case CMDSPLBLTIN:
986	#ifdef DEBUG
987	trputs("builtin command: "); trargs(argv);
988	#endif
989	mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
990	if (flags == EV_BACKCMD) {
991	psh->memout.nleft = 0;
992	psh->memout.nextc = psh->memout.buf;
993	psh->memout.bufsize = 64;
994	mode \|= REDIR_BACKQ;
995	}
996	e = -1;
997	savehandler = psh->handler;
998	savecmdname = psh->commandname;
999	psh->handler = &jmploc;
1000	if (!setjmp(jmploc.loc)) {
1001	/* We need to ensure the command hash table isn't
1002	* corruped by temporary PATH assignments.
1003	* However we must ensure the 'local' command works!
1004	*/
1005	if (path != pathval(psh) && (cmdentry.u.bltin == hashcmd \|\|
1006	cmdentry.u.bltin == typecmd)) {
1007	savelocalvars = psh->localvars;
1008	psh->localvars = 0;
1009	mklocal(psh, path - 5 /* PATH= */, 0);
1010	temp_path = 1;
1011	} else
1012	temp_path = 0;
1013	redirect(psh, cmd->ncmd.redirect, mode);
1014
1015	/* exec is a special builtin, but needs this list... */
1016	psh->cmdenviron = varlist.list;
1017	/* we must check 'readonly' flag for all builtins */
1018	listsetvar(psh, varlist.list,
1019	cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
1020	psh->commandname = argv[0];
1021	/* initialize nextopt */
1022	psh->argptr = argv + 1;
1023	psh->optptr = NULL;
1024	/* and getopt */
1025	/** @todo fix getop usage! */
1026	#if defined(__FreeBSD__) \|\| defined(__EMX__) \|\| defined(__APPLE__)
1027	optreset = 1;
1028	optind = 1;
1029	#else
1030	optind = 0; /* init */
1031	#endif
1032
1033	psh->exitstatus = cmdentry.u.bltin(psh, argc, argv);
1034	} else {
1035	e = psh->exception;
1036	psh->exitstatus = e == EXINT ? SIGINT + 128 :
1037	e == EXEXEC ? psh->exerrno : 2;
1038	}
1039	psh->handler = savehandler;
1040	output_flushall(psh);
1041	psh->out1 = &psh->output;
1042	psh->out2 = &psh->errout;
1043	freestdout(psh);
1044	if (temp_path) {
1045	poplocalvars(psh);
1046	psh->localvars = savelocalvars;
1047	}
1048	psh->cmdenviron = NULL;
1049	if (e != EXSHELLPROC) {
1050	psh->commandname = savecmdname;
1051	if (flags & EV_EXIT)
1052	exitshell(psh, psh->exitstatus);
1053	}
1054	if (e != -1) {
1055	if ((e != EXERROR && e != EXEXEC)
1056	\|\| cmdentry.cmdtype == CMDSPLBLTIN)
1057	exraise(psh, e);
1058	FORCEINTON;
1059	}
1060	if (cmdentry.u.bltin != execcmd)
1061	popredir(psh);
1062	if (flags == EV_BACKCMD) {
1063	backcmd->buf = psh->memout.buf;
1064	backcmd->nleft = psh->memout.nextc - psh->memout.buf;
1065	psh->memout.buf = NULL;
1066	}
1067	break;
1068
1069	default:
1070	#ifdef DEBUG
1071	trputs("normal command: "); trargs(argv);
1072	#endif
1073	clearredir(psh, psh->vforked);
1074	redirect(psh, cmd->ncmd.redirect, psh->vforked ? REDIR_VFORK : 0);
1075	if (!psh->vforked)
1076	for (sp = varlist.list ; sp ; sp = sp->next)
1077	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1078	envp = environment(psh);
1079	shellexec(psh, argv, envp, path, cmdentry.u.index, psh->vforked);
1080	break;
1081	}
1082	goto out;
1083
1084	parent: /* parent process gets here (if we forked) */
1085	if (mode == FORK_FG) { /* argument to fork */
1086	psh->exitstatus = waitforjob(psh, jp);
1087	} else if (mode == FORK_NOJOB) {
1088	backcmd->fd = pip[0];
1089	shfile_close(&psh->fdtab, pip[1]);
1090	backcmd->jp = jp;
1091	}
1092	FORCEINTON;
1093
1094	out:
1095	if (lastarg)
1096	/* dsl: I think this is intended to be used to support
1097	* '_' in 'vi' command mode during line editing...
1098	* However I implemented that within libedit itself.
1099	*/
1100	setvar(psh, "_", lastarg, 0);
1101	popstackmark(psh, &smark);
1102
1103	if (psh->eflag && psh->exitstatus && !(flags & EV_TESTED))
1104	exitshell(psh, psh->exitstatus);
1105	}
1106
1107
1108	/*
1109	* Search for a command. This is called before we fork so that the
1110	* location of the command will be available in the parent as well as
1111	* the child. The check for "goodname" is an overly conservative
1112	* check that the name will not be subject to expansion.
1113	*/
1114
1115	STATIC void
1116	prehash(shinstance psh, union node n)
1117	{
1118	struct cmdentry entry;
1119
1120	if (n->type == NCMD && n->ncmd.args)
1121	if (goodname(n->ncmd.args->narg.text))
1122	find_command(psh, n->ncmd.args->narg.text, &entry, 0,
1123	pathval(psh));
1124	}
1125
1126
1127
1128	/*
1129	* Builtin commands. Builtin commands whose functions are closely
1130	* tied to evaluation are implemented here.
1131	*/
1132
1133	/*
1134	* No command given.
1135	*/
1136
1137	int
1138	bltincmd(shinstance psh, int argc, char *argv)
1139	{
1140	/*
1141	* Preserve psh->exitstatus of a previous possible redirection
1142	* as POSIX mandates
1143	*/
1144	return psh->exitstatus;
1145	}
1146
1147
1148	/*
1149	* Handle break and continue commands. Break, continue, and return are
1150	* all handled by setting the psh->evalskip flag. The evaluation routines
1151	* above all check this flag, and if it is set they start skipping
1152	* commands rather than executing them. The variable skipcount is
1153	* the number of loops to break/continue, or the number of function
1154	* levels to return. (The latter is always 1.) It should probably
1155	* be an error to break out of more loops than exist, but it isn't
1156	* in the standard shell so we don't make it one here.
1157	*/
1158
1159	int
1160	breakcmd(shinstance psh, int argc, char *argv)
1161	{
1162	int n = argc > 1 ? number(argv[1]) : 1;
1163
1164	if (n > psh->loopnest)
1165	n = psh->loopnest;
1166	if (n > 0) {
1167	psh->evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1168	psh->skipcount = n;
1169	}
1170	return 0;
1171	}
1172
1173
1174	/*
1175	* The return command.
1176	*/
1177
1178	int
1179	returncmd(shinstance psh, int argc, char *argv)
1180	{
1181	int ret = argc > 1 ? number(argv[1]) : psh->exitstatus;
1182
1183	if (psh->funcnest) {
1184	psh->evalskip = SKIPFUNC;
1185	psh->skipcount = 1;
1186	return ret;
1187	}
1188	else {
1189	/* Do what ksh does; skip the rest of the file */
1190	psh->evalskip = SKIPFILE;
1191	psh->skipcount = 1;
1192	return ret;
1193	}
1194	}
1195
1196
1197	int
1198	falsecmd(shinstance psh, int argc, char *argv)
1199	{
1200	return 1;
1201	}
1202
1203
1204	int
1205	truecmd(shinstance psh, int argc, char *argv)
1206	{
1207	return 0;
1208	}
1209
1210
1211	int
1212	execcmd(shinstance psh, int argc, char *argv)
1213	{
1214	if (argc > 1) {
1215	struct strlist *sp;
1216
1217	psh->iflag = 0; /* exit on error */
1218	psh->mflag = 0;
1219	optschanged(psh);
1220	for (sp = psh->cmdenviron; sp; sp = sp->next)
1221	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1222	shellexec(psh, argv + 1, environment(psh), pathval(psh), 0, 0);
1223	}
1224	return 0;
1225	}
1226
1227	static int
1228	conv_time(clock_t ticks, char *seconds, size_t l)
1229	{
1230	static clock_t tpm = 0;
1231	clock_t mins;
1232	int i;
1233
1234	if (!tpm)
1235	tpm = /sysconf(_SC_CLK_TCK)/sh_sysconf_clk_tck() * 60;
1236
1237	mins = ticks / tpm;
1238	snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
1239
1240	if (seconds[0] == '6' && seconds[1] == '0') {
1241	/* 59.99995 got rounded up... */
1242	mins++;
1243	strlcpy(seconds, "0.0", l);
1244	return mins;
1245	}
1246
1247	/* suppress trailing zeros */
1248	i = strlen(seconds) - 1;
1249	for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
1250	seconds[i] = 0;
1251	return mins;
1252	}
1253
1254	int
1255	timescmd(shinstance psh, int argc, char *argv)
1256	{
1257	struct sh_tms tms;
1258	int u, s, cu, cs;
1259	char us[8], ss[8], cus[8], css[8];
1260
1261	nextopt(psh, "");
1262
1263	sh_times(&tms);
1264
1265	u = conv_time(tms.tms_utime, us, sizeof(us));
1266	s = conv_time(tms.tms_stime, ss, sizeof(ss));
1267	cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
1268	cs = conv_time(tms.tms_cstime, css, sizeof(css));
1269
1270	outfmt(psh->out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
1271	u, us, s, ss, cu, cus, cs, css);
1272
1273	return 0;
1274	}

Note: See TracBrowser for help on using the repository browser.

Context Navigation

source: trunk/src/ash-messup/eval.c@ 1115

Download in other formats: