eval.c@ 2438

Last change on this file since 2438 was 2424, checked in by bird, 14 years ago
kash: Some S-bahn optimizations.
Property svn:eol-style set to `LF` Property svn:keywords set to `Id`
File size: 29.2 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	#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	arglist.lastp = &arglist.list;
709	varflag = 1;
710	/* Expand arguments, ignoring the initial 'name=value' ones */
711	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
712	char *p = argp->narg.text;
713	if (varflag && is_name(*p)) {
714	do {
715	p++;
716	} while (is_in_name(*p));
717	if (*p == '=')
718	continue;
719	}
720	expandarg(psh, argp, &arglist, EXP_FULL \| EXP_TILDE);
721	varflag = 0;
722	}
723	*arglist.lastp = NULL;
724
725	expredir(psh, cmd->ncmd.redirect);
726
727	/* Now do the initial 'name=value' ones we skipped above */
728	varlist.lastp = &varlist.list;
729	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
730	char *p = argp->narg.text;
731	if (!is_name(*p))
732	break;
733	do
734	p++;
735	while (is_in_name(*p));
736	if (*p != '=')
737	break;
738	expandarg(psh, argp, &varlist, EXP_VARTILDE);
739	}
740	*varlist.lastp = NULL;
741
742	argc = 0;
743	for (sp = arglist.list ; sp ; sp = sp->next)
744	argc++;
745	argv = stalloc(psh, sizeof (char ) (argc + 1));
746
747	for (sp = arglist.list ; sp ; sp = sp->next) {
748	TRACE((psh, "evalcommand arg: %s\n", sp->text));
749	*argv++ = sp->text;
750	}
751	*argv = NULL;
752	lastarg = NULL;
753	if (iflag(psh) && psh->funcnest == 0 && argc > 0)
754	lastarg = argv[-1];
755	argv -= argc;
756
757	/* Print the command if xflag is set. */
758	if (xflag(psh)) {
759	char sep = 0;
760	out2str(psh, ps4val(psh));
761	for (sp = varlist.list ; sp ; sp = sp->next) {
762	if (sep != 0)
763	outc(sep, &psh->errout);
764	out2str(psh, sp->text);
765	sep = ' ';
766	}
767	for (sp = arglist.list ; sp ; sp = sp->next) {
768	if (sep != 0)
769	outc(sep, &psh->errout);
770	out2str(psh, sp->text);
771	sep = ' ';
772	}
773	outc('\n', &psh->errout);
774	flushout(&psh->errout);
775	}
776
777	/* Now locate the command. */
778	if (argc == 0) {
779	cmdentry.cmdtype = CMDSPLBLTIN;
780	cmdentry.u.bltin = bltincmd;
781	} else {
782	static const char PATH[] = "PATH=";
783	int cmd_flags = DO_ERR;
784
785	/*
786	* Modify the command lookup path, if a PATH= assignment
787	* is present
788	*/
789	for (sp = varlist.list; sp; sp = sp->next)
790	if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
791	path = sp->text + sizeof(PATH) - 1;
792
793	do {
794	int argsused, use_syspath;
795	find_command(psh, argv[0], &cmdentry, cmd_flags, path);
796	if (cmdentry.cmdtype == CMDUNKNOWN) {
797	psh->exitstatus = 127;
798	flushout(&psh->errout);
799	goto out;
800	}
801
802	/* implement the 'command' builtin here */
803	if (cmdentry.cmdtype != CMDBUILTIN \|\|
804	cmdentry.u.bltin != bltincmd)
805	break;
806	cmd_flags \|= DO_NOFUNC;
807	argsused = parse_command_args(psh, argc, argv, &use_syspath);
808	if (argsused == 0) {
809	/* use 'type' builting to display info */
810	cmdentry.u.bltin = typecmd;
811	break;
812	}
813	argc -= argsused;
814	argv += argsused;
815	if (use_syspath)
816	path = syspath(psh) + 5;
817	} while (argc != 0);
818	if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
819	/* posix mandates that 'command <splbltin>' act as if
820	<splbltin> was a normal builtin */
821	cmdentry.cmdtype = CMDBUILTIN;
822	}
823
824	/* Fork off a child process if necessary. */
825	if (cmd->ncmd.backgnd
826	\|\| (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
827	\|\| ((flags & EV_BACKCMD) != 0
828	&& ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN)
829	\|\| cmdentry.u.bltin == dotcmd
830	\|\| cmdentry.u.bltin == evalcmd))) {
831	INTOFF;
832	jp = makejob(psh, cmd, 1);
833	mode = cmd->ncmd.backgnd;
834	if (flags & EV_BACKCMD) {
835	mode = FORK_NOJOB;
836	if (sh_pipe(psh, pip) < 0)
837	error(psh, "Pipe call failed");
838	}
839	#ifdef DO_SHAREDVFORK
840	/* It is essential that if DO_SHAREDVFORK is defined that the
841	* child's address space is actually shared with the parent as
842	* we rely on this.
843	*/
844	if (cmdentry.cmdtype == CMDNORMAL) {
845	pid_t pid;
846
847	savelocalvars = psh->localvars;
848	psh->localvars = NULL;
849	psh->vforked = 1;
850	switch (pid = vfork()) {
851	case -1:
852	TRACE((psh, "Vfork failed, errno=%d\n", errno));
853	INTON;
854	error(psh, "Cannot vfork");
855	break;
856	case 0:
857	/* Make sure that exceptions only unwind to
858	* after the vfork(2)
859	*/
860	if (setjmp(jmploc.loc)) {
861	if (psh->exception == EXSHELLPROC) {
862	/* We can't progress with the vfork,
863	* so, set vforked = 2 so the parent
864	* knows, and _exit();
865	*/
866	psh->vforked = 2;
867	sh__exit(psh, 0);
868	} else {
869	sh__exit(psh, psh->exerrno);
870	}
871	}
872	savehandler = psh->handler;
873	psh->handler = &jmploc;
874	listmklocal(psh, varlist.list, VEXPORT \| VNOFUNC);
875	forkchild(psh, jp, cmd, mode, psh->vforked);
876	break;
877	default:
878	psh->handler = savehandler; /* restore from vfork(2) */
879	poplocalvars(psh);
880	psh->localvars = savelocalvars;
881	if (psh->vforked == 2) {
882	psh->vforked = 0;
883
884	(void)sh_waitpid(psh, pid, NULL, 0);
885	/* We need to progress in a normal fork fashion */
886	goto normal_fork;
887	}
888	psh->vforked = 0;
889	forkparent(psh, jp, cmd, mode, pid);
890	goto parent;
891	}
892	} else {
893	normal_fork:
894	#endif
895	if (forkshell(psh, jp, cmd, mode) != 0)
896	goto parent; /* at end of routine */
897	FORCEINTON;
898	#ifdef DO_SHAREDVFORK
899	}
900	#endif
901	if (flags & EV_BACKCMD) {
902	if (!psh->vforked) {
903	FORCEINTON;
904	}
905	shfile_close(&psh->fdtab, pip[0]);
906	if (pip[1] != 1) {
907	movefd(psh, pip[1], 1);
908	}
909	}
910	flags \|= EV_EXIT;
911	}
912
913	/* This is the child process if a fork occurred. */
914	/* Execute the command. */
915	switch (cmdentry.cmdtype) {
916	case CMDFUNCTION:
917	#ifdef DEBUG
918	trputs(psh, "Shell function: "); trargs(psh, argv);
919	#endif
920	redirect(psh, cmd->ncmd.redirect, REDIR_PUSH);
921	saveparam = psh->shellparam;
922	psh->shellparam.malloc = 0;
923	psh->shellparam.reset = 1;
924	psh->shellparam.nparam = argc - 1;
925	psh->shellparam.p = argv + 1;
926	psh->shellparam.optnext = NULL;
927	INTOFF;
928	savelocalvars = psh->localvars;
929	psh->localvars = NULL;
930	INTON;
931	if (setjmp(jmploc.loc)) {
932	if (psh->exception == EXSHELLPROC) {
933	freeparam(psh, (volatile struct shparam *)
934	&saveparam);
935	} else {
936	freeparam(psh, &psh->shellparam);
937	psh->shellparam = saveparam;
938	}
939	poplocalvars(psh);
940	psh->localvars = savelocalvars;
941	psh->handler = savehandler;
942	longjmp(psh->handler->loc, 1);
943	}
944	savehandler = psh->handler;
945	psh->handler = &jmploc;
946	listmklocal(psh, varlist.list, 0);
947	/* stop shell blowing its stack */
948	if (++psh->funcnest > 1000)
949	error(psh, "too many nested function calls");
950	evaltree(psh, cmdentry.u.func, flags & EV_TESTED);
951	psh->funcnest--;
952	INTOFF;
953	poplocalvars(psh);
954	psh->localvars = savelocalvars;
955	freeparam(psh, &psh->shellparam);
956	psh->shellparam = saveparam;
957	psh->handler = savehandler;
958	popredir(psh);
959	INTON;
960	if (psh->evalskip == SKIPFUNC) {
961	psh->evalskip = 0;
962	psh->skipcount = 0;
963	}
964	if (flags & EV_EXIT)
965	exitshell(psh, psh->exitstatus);
966	break;
967
968	case CMDBUILTIN:
969	case CMDSPLBLTIN:
970	#ifdef DEBUG
971	trputs(psh, "builtin command: "); trargs(psh, argv);
972	#endif
973	mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
974	if (flags == EV_BACKCMD) {
975	psh->memout.nleft = 0;
976	psh->memout.nextc = psh->memout.buf;
977	psh->memout.bufsize = 64;
978	mode \|= REDIR_BACKQ;
979	}
980	e = -1;
981	savehandler = psh->handler;
982	savecmdname = psh->commandname;
983	psh->handler = &jmploc;
984	if (!setjmp(jmploc.loc)) {
985	/* We need to ensure the command hash table isn't
986	* corruped by temporary PATH assignments.
987	* However we must ensure the 'local' command works!
988	*/
989	if (path != pathval(psh) && (cmdentry.u.bltin == hashcmd \|\|
990	cmdentry.u.bltin == typecmd)) {
991	savelocalvars = psh->localvars;
992	psh->localvars = 0;
993	mklocal(psh, path - 5 /* PATH= */, 0);
994	temp_path = 1;
995	} else
996	temp_path = 0;
997	redirect(psh, cmd->ncmd.redirect, mode);
998
999	/* exec is a special builtin, but needs this list... */
1000	psh->cmdenviron = varlist.list;
1001	/* we must check 'readonly' flag for all builtins */
1002	listsetvar(psh, varlist.list,
1003	cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
1004	psh->commandname = argv[0];
1005	/* initialize nextopt */
1006	psh->argptr = argv + 1;
1007	psh->optptr = NULL;
1008	/* and getopt */
1009	#if 0 /** @todo fix getop usage! */
1010	#if defined(__FreeBSD__) \|\| defined(__EMX__) \|\| defined(__APPLE__)
1011	optreset = 1;
1012	optind = 1;
1013	#else
1014	optind = 0; /* init */
1015	#endif
1016	#endif
1017
1018	psh->exitstatus = cmdentry.u.bltin(psh, argc, argv);
1019	} else {
1020	e = psh->exception;
1021	psh->exitstatus = e == EXINT ? SIGINT + 128 :
1022	e == EXEXEC ? psh->exerrno : 2;
1023	}
1024	psh->handler = savehandler;
1025	output_flushall(psh);
1026	psh->out1 = &psh->output;
1027	psh->out2 = &psh->errout;
1028	freestdout(psh);
1029	if (temp_path) {
1030	poplocalvars(psh);
1031	psh->localvars = savelocalvars;
1032	}
1033	psh->cmdenviron = NULL;
1034	if (e != EXSHELLPROC) {
1035	psh->commandname = savecmdname;
1036	if (flags & EV_EXIT)
1037	exitshell(psh, psh->exitstatus);
1038	}
1039	if (e != -1) {
1040	if ((e != EXERROR && e != EXEXEC)
1041	\|\| cmdentry.cmdtype == CMDSPLBLTIN)
1042	exraise(psh, e);
1043	FORCEINTON;
1044	}
1045	if (cmdentry.u.bltin != execcmd)
1046	popredir(psh);
1047	if (flags == EV_BACKCMD) {
1048	backcmd->buf = psh->memout.buf;
1049	backcmd->nleft = (int)(psh->memout.nextc - psh->memout.buf);
1050	psh->memout.buf = NULL;
1051	}
1052	break;
1053
1054	default:
1055	#ifdef DEBUG
1056	trputs(psh, "normal command: "); trargs(psh, argv);
1057	#endif
1058	clearredir(psh, psh->vforked);
1059	redirect(psh, cmd->ncmd.redirect, psh->vforked ? REDIR_VFORK : 0);
1060	if (!psh->vforked)
1061	for (sp = varlist.list ; sp ; sp = sp->next)
1062	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1063	envp = environment(psh);
1064	shellexec(psh, argv, envp, path, cmdentry.u.index, psh->vforked);
1065	break;
1066	}
1067	goto out;
1068
1069	parent: /* parent process gets here (if we forked) */
1070	if (mode == FORK_FG) { /* argument to fork */
1071	psh->exitstatus = waitforjob(psh, jp);
1072	} else if (mode == FORK_NOJOB) {
1073	backcmd->fd = pip[0];
1074	shfile_close(&psh->fdtab, pip[1]);
1075	backcmd->jp = jp;
1076	}
1077	FORCEINTON;
1078
1079	out:
1080	if (lastarg)
1081	/* dsl: I think this is intended to be used to support
1082	* '_' in 'vi' command mode during line editing...
1083	* However I implemented that within libedit itself.
1084	*/
1085	setvar(psh, "_", lastarg, 0);
1086	popstackmark(psh, &smark);
1087
1088	if (eflag(psh) && psh->exitstatus && !(flags & EV_TESTED))
1089	exitshell(psh, psh->exitstatus);
1090	}
1091
1092
1093	/*
1094	* Search for a command. This is called before we fork so that the
1095	* location of the command will be available in the parent as well as
1096	* the child. The check for "goodname" is an overly conservative
1097	* check that the name will not be subject to expansion.
1098	*/
1099
1100	STATIC void
1101	prehash(shinstance psh, union node n)
1102	{
1103	struct cmdentry entry;
1104
1105	if (n->type == NCMD && n->ncmd.args)
1106	if (goodname(n->ncmd.args->narg.text))
1107	find_command(psh, n->ncmd.args->narg.text, &entry, 0,
1108	pathval(psh));
1109	}
1110
1111
1112
1113	/*
1114	* Builtin commands. Builtin commands whose functions are closely
1115	* tied to evaluation are implemented here.
1116	*/
1117
1118	/*
1119	* No command given.
1120	*/
1121
1122	int
1123	bltincmd(shinstance psh, int argc, char *argv)
1124	{
1125	/*
1126	* Preserve psh->exitstatus of a previous possible redirection
1127	* as POSIX mandates
1128	*/
1129	return psh->back_exitstatus;
1130	}
1131
1132
1133	/*
1134	* Handle break and continue commands. Break, continue, and return are
1135	* all handled by setting the psh->evalskip flag. The evaluation routines
1136	* above all check this flag, and if it is set they start skipping
1137	* commands rather than executing them. The variable skipcount is
1138	* the number of loops to break/continue, or the number of function
1139	* levels to return. (The latter is always 1.) It should probably
1140	* be an error to break out of more loops than exist, but it isn't
1141	* in the standard shell so we don't make it one here.
1142	*/
1143
1144	int
1145	breakcmd(shinstance psh, int argc, char *argv)
1146	{
1147	int n = argc > 1 ? number(psh, argv[1]) : 1;
1148
1149	if (n > psh->loopnest)
1150	n = psh->loopnest;
1151	if (n > 0) {
1152	psh->evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1153	psh->skipcount = n;
1154	}
1155	return 0;
1156	}
1157
1158
1159	/*
1160	* The return command.
1161	*/
1162
1163	int
1164	returncmd(shinstance psh, int argc, char *argv)
1165	{
1166	#if 0
1167	int ret = argc > 1 ? number(psh, argv[1]) : psh->exitstatus;
1168	#else
1169	int ret;
1170	if (argc > 1) {
1171	/* make return -1 and VSC lite work ... */
1172	if (argv[1][0] != '-' \|\| !is_number(&argv[1][1]))
1173	ret = number(psh, argv[1]);
1174	else
1175	ret = -number(psh, &argv[1][1]) & 255; /* take the bash approach */
1176	} else {
1177	ret = psh->exitstatus;
1178	}
1179	#endif
1180
1181	if (psh->funcnest) {
1182	psh->evalskip = SKIPFUNC;
1183	psh->skipcount = 1;
1184	return ret;
1185	}
1186	else {
1187	/* Do what ksh does; skip the rest of the file */
1188	psh->evalskip = SKIPFILE;
1189	psh->skipcount = 1;
1190	return ret;
1191	}
1192	}
1193
1194
1195	int
1196	falsecmd(shinstance psh, int argc, char *argv)
1197	{
1198	return 1;
1199	}
1200
1201
1202	int
1203	truecmd(shinstance psh, int argc, char *argv)
1204	{
1205	return 0;
1206	}
1207
1208
1209	int
1210	execcmd(shinstance psh, int argc, char *argv)
1211	{
1212	if (argc > 1) {
1213	struct strlist *sp;
1214
1215	iflag(psh) = 0; /* exit on error */
1216	mflag(psh) = 0;
1217	optschanged(psh);
1218	for (sp = psh->cmdenviron; sp; sp = sp->next)
1219	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1220	shellexec(psh, argv + 1, environment(psh), pathval(psh), 0, 0);
1221	}
1222	return 0;
1223	}
1224
1225	static int
1226	conv_time(clock_t ticks, char *seconds, size_t l)
1227	{
1228	static clock_t tpm = 0;
1229	clock_t mins;
1230	size_t i;
1231
1232	if (!tpm)
1233	tpm = /sysconf(_SC_CLK_TCK)/sh_sysconf_clk_tck() * 60;
1234
1235	mins = ticks / tpm;
1236	#ifdef _MSC_VER
1237	{
1238	char tmp[64];
1239	sprintf(tmp, "%.4f", (ticks - mins * tpm) * 60.0 / tpm);
1240	strlcpy(seconds, tmp, l);
1241	}
1242	#else
1243	snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
1244	#endif
1245
1246	if (seconds[0] == '6' && seconds[1] == '0') {
1247	/* 59.99995 got rounded up... */
1248	mins++;
1249	strlcpy(seconds, "0.0", l);
1250	return mins;
1251	}
1252
1253	/* suppress trailing zeros */
1254	i = strlen(seconds) - 1;
1255	for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
1256	seconds[i] = 0;
1257	return mins;
1258	}
1259
1260	int
1261	timescmd(shinstance psh, int argc, char *argv)
1262	{
1263	shtms tms;
1264	int u, s, cu, cs;
1265	char us[8], ss[8], cus[8], css[8];
1266
1267	nextopt(psh, "");
1268
1269	sh_times(psh, &tms);
1270
1271	u = conv_time(tms.tms_utime, us, sizeof(us));
1272	s = conv_time(tms.tms_stime, ss, sizeof(ss));
1273	cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
1274	cs = conv_time(tms.tms_cstime, css, sizeof(css));
1275
1276	outfmt(psh->out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
1277	u, us, s, ss, cu, cus, cs, css);
1278
1279	return 0;
1280	}

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

source: kBuild/trunk/src/kash/eval.c@ 2438

Download in other formats: