Context Navigation

source: trunk/src/kash/eval.c@ 3433

Last change on this file since 3433 was 3433, checked in by bird, 5 years ago
kash: refactoring forkshell(); simple stuff.
Property svn:eol-style set to `LF` Property svn:keywords set to `Id`
File size: 31.5 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	#ifdef KASH_USE_FORKSHELL2
416	/*
417	* Child of evalsubshell.
418	*/
419	struct evalsubshellchild
420	{
421	int flags;
422	int backgnd;
423	};
424
425	static int evalsubshell_child(shinstance psh, union node n, void *argp)
426	{
427	struct evalsubshellchild args = (struct evalsubshellchild )argp;
428
429	INTON;
430	if (args.backgnd)
431	args.flags &=~ EV_TESTED;
432	redirect(psh, n->nredir.redirect, 0);
433	/* never returns */
434	evaltree(psh, n->nredir.n, args.flags \| EV_EXIT);
435	/** @todo make us return here. */
436	return 0;
437	}
438	#endif /* KASH_USE_FORKSHELL2 */
439
440
441	/*
442	* Kick off a subshell to evaluate a tree.
443	*/
444
445	STATIC void
446	evalsubshell(shinstance psh, union node n, int flags)
447	{
448	struct job *jp;
449	int backgnd = (n->type == NBACKGND);
450
451	expredir(psh, n->nredir.redirect);
452	INTOFF;
453	jp = makejob(psh, n, 1);
454	#ifdef KASH_USE_FORKSHELL2
455	{
456	struct evalsubshellchild args;
457	args.flags = flags;
458	args.backgnd = backgnd;
459	forkshell2(psh, jp, n, backgnd ? FORK_BG : FORK_FG,
460	evalsubshell_child, n, &args, sizeof(args));
461	}
462	#else
463	if (forkshell(psh, jp, n, backgnd ? FORK_BG : FORK_FG) == 0) {
464	INTON;
465	if (backgnd)
466	flags &=~ EV_TESTED;
467	redirect(psh, n->nredir.redirect, 0);
468	/* never returns */
469	evaltree(psh, n->nredir.n, flags \| EV_EXIT);
470	}
471	#endif
472	if (! backgnd)
473	psh->exitstatus = waitforjob(psh, jp);
474	INTON;
475	}
476
477
478
479	/*
480	* Compute the names of the files in a redirection list.
481	*/
482
483	STATIC void
484	expredir(shinstance psh, union node n)
485	{
486	union node *redir;
487
488	for (redir = n ; redir ; redir = redir->nfile.next) {
489	struct arglist fn;
490	fn.lastp = &fn.list;
491	switch (redir->type) {
492	case NFROMTO:
493	case NFROM:
494	case NTO:
495	case NCLOBBER:
496	case NAPPEND:
497	expandarg(psh, redir->nfile.fname, &fn, EXP_TILDE \| EXP_REDIR);
498	redir->nfile.expfname = fn.list->text;
499	break;
500	case NFROMFD:
501	case NTOFD:
502	if (redir->ndup.vname) {
503	expandarg(psh, redir->ndup.vname, &fn, EXP_FULL \| EXP_TILDE);
504	fixredir(psh, redir, fn.list->text, 1);
505	}
506	break;
507	}
508	}
509	}
510
511
512	#ifdef KASH_USE_FORKSHELL2
513	/*
514	* Child of evalpipe.
515	*/
516	struct evalpipechild
517	{
518	int prevfd;
519	int pip[2];
520	};
521
522	static int evalpipe_child(shinstance psh, union node n, void *argp)
523	{
524	struct evalpipechild args = (struct evalpipechild )argp;
525
526	if (args.prevfd > 0) {
527	movefd(psh, args.prevfd, 0);
528	}
529	if (args.pip[1] >= 0) {
530	shfile_close(&psh->fdtab, args.pip[0]);
531	if (args.pip[1] != 1) {
532	movefd(psh, args.pip[1], 1);
533	}
534	}
535	evaltree(psh, n, EV_EXIT);
536	/** @todo make it return thru here. */
537	return 0;
538	}
539	#endif /* KASH_USE_FORKSHELL2 */
540
541	/*
542	* Evaluate a pipeline. All the processes in the pipeline are children
543	* of the process creating the pipeline. (This differs from some versions
544	* of the shell, which make the last process in a pipeline the parent
545	* of all the rest.)
546	*/
547
548	STATIC void
549	evalpipe(shinstance psh, union node n)
550	{
551	struct job *jp;
552	struct nodelist *lp;
553	int pipelen;
554	int prevfd;
555	int pip[2];
556
557	TRACE((psh, "evalpipe(0x%lx) called\n", (long)n));
558	pipelen = 0;
559	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
560	pipelen++;
561	INTOFF;
562	jp = makejob(psh, n, pipelen);
563	prevfd = -1;
564	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
565	prehash(psh, lp->n);
566	pip[1] = -1;
567	if (lp->next) {
568	if (sh_pipe(psh, pip) < 0) {
569	shfile_close(&psh->fdtab, prevfd);
570	error(psh, "Pipe call failed");
571	}
572	}
573	#ifdef KASH_USE_FORKSHELL2
574	{
575	struct evalpipechild args;
576	args.prevfd = prevfd;
577	args.pip[0] = pip[0];
578	args.pip[1] = pip[1];
579	forkshell2(psh, jp, lp->n, n->npipe.backgnd ? FORK_BG : FORK_FG,
580	evalpipe_child, lp->n, &args, sizeof(args));
581	}
582	#else
583	if (forkshell(psh, jp, lp->n, n->npipe.backgnd ? FORK_BG : FORK_FG) == 0) {
584	INTON;
585	if (prevfd > 0) {
586	movefd(psh, prevfd, 0);
587	}
588	if (pip[1] >= 0) {
589	shfile_close(&psh->fdtab, pip[0]);
590	if (pip[1] != 1) {
591	movefd(psh, pip[1], 1);
592	}
593	}
594	evaltree(psh, lp->n, EV_EXIT);
595	}
596	#endif
597	if (prevfd >= 0)
598	shfile_close(&psh->fdtab, prevfd);
599	prevfd = pip[0];
600	shfile_close(&psh->fdtab, pip[1]);
601	}
602	if (n->npipe.backgnd == 0) {
603	psh->exitstatus = waitforjob(psh, jp);
604	TRACE((psh, "evalpipe: job done exit status %d\n", psh->exitstatus));
605	}
606	INTON;
607	}
608
609	#ifdef KASH_USE_FORKSHELL2
610	/*
611	* evalbackcmd child.
612	*/
613	struct evalbackcmdchild
614	{
615	int pip[2];
616	};
617
618	static int evalbackcmd_child(shinstance psh, union node n, void *argp)
619	{
620	struct evalbackcmdchild args = (struct evalbackcmdchild )argp;
621
622	FORCEINTON;
623	shfile_close(&psh->fdtab, args.pip[0]);
624	if (args.pip[1] != 1) {
625	movefd(psh, args.pip[1], 1);
626	}
627	eflag(psh) = 0;
628	evaltree(psh, n, EV_EXIT);
629	/* NOTREACHED / /* @todo make it return here to simplify thread handling (no need for setjmp). */
630	return 0;
631	}
632	#endif /* KASH_USE_FORKSHELL2 */
633
634	/*
635	* Execute a command inside back quotes. If it's a builtin command, we
636	* want to save its output in a block obtained from malloc. Otherwise
637	* we fork off a subprocess and get the output of the command via a pipe.
638	* Should be called with interrupts off.
639	*/
640
641	void
642	evalbackcmd(shinstance psh, union node n, struct backcmd *result)
643	{
644	int pip[2];
645	struct job *jp;
646	struct stackmark smark; /* unnecessary */
647
648	setstackmark(psh, &smark);
649	result->fd = -1;
650	result->buf = NULL;
651	result->nleft = 0;
652	result->jp = NULL;
653	if (n == NULL) {
654	goto out;
655	}
656	#ifdef notyet
657	/*
658	* For now we disable executing builtins in the same
659	* context as the shell, because we are not keeping
660	* enough state to recover from changes that are
661	* supposed only to affect subshells. eg. echo "`cd /`"
662	*/
663	if (n->type == NCMD) {
664	psh->exitstatus = opsh->exitstatus;
665	evalcommand(psh, n, EV_BACKCMD, result);
666	} else
667	#endif
668	{
669	INTOFF;
670	if (sh_pipe(psh, pip) < 0)
671	error(psh, "Pipe call failed");
672	jp = makejob(psh, n, 1);
673	#ifdef KASH_USE_FORKSHELL2
674	{
675	struct evalbackcmdchild args;
676	args.pip[0] = pip[0];
677	args.pip[1] = pip[1];
678	forkshell2(psh, jp, n, FORK_NOJOB,
679	evalbackcmd_child, n, &args, sizeof(args));
680	}
681	#else
682	if (forkshell(psh, jp, n, FORK_NOJOB) == 0) {
683	FORCEINTON;
684	shfile_close(&psh->fdtab, pip[0]);
685	if (pip[1] != 1) {
686	movefd(psh, pip[1], 1);
687	}
688	eflag(psh) = 0;
689	evaltree(psh, n, EV_EXIT);
690	/* NOTREACHED */
691	}
692	#endif
693	shfile_close(&psh->fdtab, pip[1]);
694	result->fd = pip[0];
695	result->jp = jp;
696	INTON;
697	}
698	out:
699	popstackmark(psh, &smark);
700	TRACE((psh, "evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
701	result->fd, result->buf, result->nleft, result->jp));
702	}
703
704	static const char *
705	syspath(shinstance *psh)
706	{
707	#ifdef CTL_USER
708	static char *sys_path = NULL;
709	static int mib[] = {CTL_USER, USER_CS_PATH};
710	#endif
711	#ifdef PC_PATH_SEP
712	static char def_path[] = "PATH=/usr/bin;/bin;/usr/sbin;/sbin";
713	#else
714	static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin";
715	#endif
716	#ifdef CTL_USER
717	size_t len;
718
719	if (sys_path == NULL) {
720	if (sysctl(mib, 2, 0, &len, 0, 0) != -1 &&
721	(sys_path = ckmalloc(psh, len + 5)) != NULL &&
722	sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) {
723	memcpy(sys_path, "PATH=", 5);
724	} else {
725	ckfree(psh, sys_path);
726	/* something to keep things happy */
727	sys_path = def_path;
728	}
729	}
730	return sys_path;
731	#else
732	return def_path;
733	#endif
734	}
735
736	static int
737	parse_command_args(shinstance psh, int argc, char argv, int use_syspath)
738	{
739	int sv_argc = argc;
740	char *cp, c;
741
742	*use_syspath = 0;
743
744	for (;;) {
745	argv++;
746	if (--argc == 0)
747	break;
748	cp = *argv;
749	if (*cp++ != '-')
750	break;
751	if (*cp == '-' && cp[1] == 0) {
752	argv++;
753	argc--;
754	break;
755	}
756	while ((c = *cp++)) {
757	switch (c) {
758	case 'p':
759	*use_syspath = 1;
760	break;
761	default:
762	/* run 'typecmd' for other options */
763	return 0;
764	}
765	}
766	}
767	return sv_argc - argc;
768	}
769
770	/int vforked = 0;/
771
772	/*
773	* Execute a simple command.
774	*/
775
776	STATIC void
777	evalcommand(shinstance psh, union node cmd, int flags, struct backcmd *backcmd)
778	{
779	struct stackmark smark;
780	union node *argp;
781	struct arglist arglist;
782	struct arglist varlist;
783	char **argv;
784	int argc;
785	char **envp;
786	int numvars;
787	struct strlist *sp;
788	int mode = 0;
789	int pip[2];
790	struct cmdentry cmdentry;
791	struct job *jp;
792	struct jmploc jmploc;
793	struct jmploc *volatile savehandler;
794	char *volatile savecmdname;
795	volatile struct shparam saveparam;
796	struct localvar *volatile savelocalvars;
797	volatile int e;
798	char *lastarg;
799	const char *path = pathval(psh);
800	volatile int temp_path;
801	#if __GNUC__
802	/* Try avoid longjmp clobbering */
803	(void) &argv;
804	(void) &argc;
805	(void) &lastarg;
806	(void) &flags;
807	(void) &path;
808	(void) &mode;
809	#endif
810
811	psh->vforked = 0;
812	/* First expand the arguments. */
813	TRACE((psh, "evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
814	setstackmark(psh, &smark);
815	psh->back_exitstatus = 0;
816
817	arglist.lastp = &arglist.list;
818	/* Expand arguments, ignoring the initial 'name=value' ones */
819	for (argp = cmd->ncmd.args, numvars = 0 ; argp ; argp = argp->narg.next, numvars++) {
820	char *p = argp->narg.text;
821	char ch = *p;
822	if (is_name(ch)) {
823	do ch = *++p;
824	while (is_in_name(ch));
825	if (ch == '=')
826	continue;
827	}
828	break;
829	}
830	for (/continue on argp from above. / ; argp ; argp = argp->narg.next)
831	expandarg(psh, argp, &arglist, EXP_FULL \| EXP_TILDE);
832	*arglist.lastp = NULL;
833
834	expredir(psh, cmd->ncmd.redirect);
835
836	/* Now do the initial 'name=value' ones we skipped above */
837	varlist.lastp = &varlist.list;
838	for (argp = cmd->ncmd.args ; numvars > 0 && argp ; argp = argp->narg.next, numvars--)
839	expandarg(psh, argp, &varlist, EXP_VARTILDE);
840	*varlist.lastp = NULL;
841
842	argc = 0;
843	for (sp = arglist.list ; sp ; sp = sp->next)
844	argc++;
845	argv = stalloc(psh, sizeof (char ) (argc + 1));
846
847	for (sp = arglist.list ; sp ; sp = sp->next) {
848	TRACE((psh, "evalcommand arg: %s\n", sp->text));
849	*argv++ = sp->text;
850	}
851	*argv = NULL;
852	lastarg = NULL;
853	if (iflag(psh) && psh->funcnest == 0 && argc > 0)
854	lastarg = argv[-1];
855	argv -= argc;
856
857	/* Print the command if xflag is set. */
858	if (xflag(psh)) {
859	char sep = 0;
860	out2str(psh, ps4val(psh));
861	for (sp = varlist.list ; sp ; sp = sp->next) {
862	if (sep != 0)
863	outc(sep, &psh->errout);
864	out2str(psh, sp->text);
865	sep = ' ';
866	}
867	for (sp = arglist.list ; sp ; sp = sp->next) {
868	if (sep != 0)
869	outc(sep, &psh->errout);
870	out2str(psh, sp->text);
871	sep = ' ';
872	}
873	outc('\n', &psh->errout);
874	flushout(&psh->errout);
875	}
876
877	/* Now locate the command. */
878	if (argc == 0) {
879	cmdentry.cmdtype = CMDSPLBLTIN;
880	cmdentry.u.bltin = bltincmd;
881	} else {
882	static const char PATH[] = "PATH=";
883	int cmd_flags = DO_ERR;
884
885	/*
886	* Modify the command lookup path, if a PATH= assignment
887	* is present
888	*/
889	for (sp = varlist.list; sp; sp = sp->next)
890	if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
891	path = sp->text + sizeof(PATH) - 1;
892
893	do {
894	int argsused, use_syspath;
895	find_command(psh, argv[0], &cmdentry, cmd_flags, path);
896	if (cmdentry.cmdtype == CMDUNKNOWN) {
897	psh->exitstatus = 127;
898	flushout(&psh->errout);
899	goto out;
900	}
901
902	/* implement the 'command' builtin here */
903	if (cmdentry.cmdtype != CMDBUILTIN \|\|
904	cmdentry.u.bltin != bltincmd)
905	break;
906	cmd_flags \|= DO_NOFUNC;
907	argsused = parse_command_args(psh, argc, argv, &use_syspath);
908	if (argsused == 0) {
909	/* use 'type' builting to display info */
910	cmdentry.u.bltin = typecmd;
911	break;
912	}
913	argc -= argsused;
914	argv += argsused;
915	if (use_syspath)
916	path = syspath(psh) + 5;
917	} while (argc != 0);
918	if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
919	/* posix mandates that 'command <splbltin>' act as if
920	<splbltin> was a normal builtin */
921	cmdentry.cmdtype = CMDBUILTIN;
922	}
923
924	/* Fork off a child process if necessary. */
925	if (cmd->ncmd.backgnd
926	\|\| (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
927	\|\| ((flags & EV_BACKCMD) != 0
928	&& ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN)
929	\|\| cmdentry.u.bltin == dotcmd
930	\|\| cmdentry.u.bltin == evalcmd))) {
931	INTOFF;
932	jp = makejob(psh, cmd, 1);
933	mode = cmd->ncmd.backgnd;
934	if (flags & EV_BACKCMD) {
935	mode = FORK_NOJOB;
936	if (sh_pipe(psh, pip) < 0)
937	error(psh, "Pipe call failed");
938	}
939	#ifdef DO_SHAREDVFORK
940	/* It is essential that if DO_SHAREDVFORK is defined that the
941	* child's address space is actually shared with the parent as
942	* we rely on this.
943	*/
944	if (cmdentry.cmdtype == CMDNORMAL) {
945	pid_t pid;
946
947	savelocalvars = psh->localvars;
948	psh->localvars = NULL;
949	psh->vforked = 1;
950	switch (pid = vfork()) {
951	case -1:
952	TRACE((psh, "Vfork failed, errno=%d\n", errno));
953	INTON;
954	error(psh, "Cannot vfork");
955	break;
956	case 0:
957	/* Make sure that exceptions only unwind to
958	* after the vfork(2)
959	*/
960	if (setjmp(jmploc.loc)) {
961	if (psh->exception == EXSHELLPROC) {
962	/* We can't progress with the vfork,
963	* so, set vforked = 2 so the parent
964	* knows, and _exit();
965	*/
966	psh->vforked = 2;
967	sh__exit(psh, 0);
968	} else {
969	sh__exit(psh, psh->exerrno);
970	}
971	}
972	savehandler = psh->handler;
973	psh->handler = &jmploc;
974	listmklocal(psh, varlist.list, VEXPORT \| VNOFUNC);
975	forkchild(psh, jp, cmd, mode, psh->vforked);
976	break;
977	default:
978	psh->handler = savehandler; /* restore from vfork(2) */
979	poplocalvars(psh);
980	psh->localvars = savelocalvars;
981	if (psh->vforked == 2) {
982	psh->vforked = 0;
983
984	(void)sh_waitpid(psh, pid, NULL, 0);
985	/* We need to progress in a normal fork fashion */
986	goto normal_fork;
987	}
988	psh->vforked = 0;
989	forkparent(psh, jp, cmd, mode, pid);
990	goto parent;
991	}
992	} else {
993	normal_fork:
994	#endif
995	if (forkshell(psh, jp, cmd, mode) != 0)
996	goto parent; /* at end of routine */
997	FORCEINTON;
998	#ifdef DO_SHAREDVFORK
999	}
1000	#endif
1001	if (flags & EV_BACKCMD) {
1002	if (!psh->vforked) {
1003	FORCEINTON;
1004	}
1005	shfile_close(&psh->fdtab, pip[0]);
1006	if (pip[1] != 1) {
1007	movefd(psh, pip[1], 1);
1008	}
1009	}
1010	flags \|= EV_EXIT;
1011	}
1012
1013	/* This is the child process if a fork occurred. */
1014	/* Execute the command. */
1015	switch (cmdentry.cmdtype) {
1016	case CMDFUNCTION:
1017	#ifdef DEBUG
1018	trputs(psh, "Shell function: "); trargs(psh, argv);
1019	#endif
1020	redirect(psh, cmd->ncmd.redirect, REDIR_PUSH);
1021	saveparam = psh->shellparam;
1022	psh->shellparam.malloc = 0;
1023	psh->shellparam.reset = 1;
1024	psh->shellparam.nparam = argc - 1;
1025	psh->shellparam.p = argv + 1;
1026	psh->shellparam.optnext = NULL;
1027	INTOFF;
1028	savelocalvars = psh->localvars;
1029	psh->localvars = NULL;
1030	INTON;
1031	if (setjmp(jmploc.loc)) {
1032	if (psh->exception == EXSHELLPROC) {
1033	freeparam(psh, (volatile struct shparam *)
1034	&saveparam);
1035	} else {
1036	freeparam(psh, &psh->shellparam);
1037	psh->shellparam = saveparam;
1038	}
1039	poplocalvars(psh);
1040	psh->localvars = savelocalvars;
1041	psh->handler = savehandler;
1042	longjmp(psh->handler->loc, 1);
1043	}
1044	savehandler = psh->handler;
1045	psh->handler = &jmploc;
1046	listmklocal(psh, varlist.list, 0);
1047	/* stop shell blowing its stack */
1048	if (++psh->funcnest > 1000)
1049	error(psh, "too many nested function calls");
1050	evaltree(psh, cmdentry.u.func, flags & EV_TESTED);
1051	psh->funcnest--;
1052	INTOFF;
1053	poplocalvars(psh);
1054	psh->localvars = savelocalvars;
1055	freeparam(psh, &psh->shellparam);
1056	psh->shellparam = saveparam;
1057	psh->handler = savehandler;
1058	popredir(psh);
1059	INTON;
1060	if (psh->evalskip == SKIPFUNC) {
1061	psh->evalskip = 0;
1062	psh->skipcount = 0;
1063	}
1064	if (flags & EV_EXIT)
1065	exitshell(psh, psh->exitstatus);
1066	break;
1067
1068	case CMDBUILTIN:
1069	case CMDSPLBLTIN:
1070	#ifdef DEBUG
1071	trputs(psh, "builtin command: "); trargs(psh, argv);
1072	#endif
1073	mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
1074	if (flags == EV_BACKCMD) {
1075	psh->memout.nleft = 0;
1076	psh->memout.nextc = psh->memout.buf;
1077	psh->memout.bufsize = 64;
1078	mode \|= REDIR_BACKQ;
1079	}
1080	e = -1;
1081	savehandler = psh->handler;
1082	savecmdname = psh->commandname;
1083	psh->handler = &jmploc;
1084	if (!setjmp(jmploc.loc)) {
1085	/* We need to ensure the command hash table isn't
1086	* corruped by temporary PATH assignments.
1087	* However we must ensure the 'local' command works!
1088	*/
1089	if (path != pathval(psh) && (cmdentry.u.bltin == hashcmd \|\|
1090	cmdentry.u.bltin == typecmd)) {
1091	savelocalvars = psh->localvars;
1092	psh->localvars = 0;
1093	mklocal(psh, path - 5 /* PATH= */, 0);
1094	temp_path = 1;
1095	} else
1096	temp_path = 0;
1097	redirect(psh, cmd->ncmd.redirect, mode);
1098
1099	/* exec is a special builtin, but needs this list... */
1100	psh->cmdenviron = varlist.list;
1101	/* we must check 'readonly' flag for all builtins */
1102	listsetvar(psh, varlist.list,
1103	cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
1104	psh->commandname = argv[0];
1105	/* initialize nextopt */
1106	psh->argptr = argv + 1;
1107	psh->optptr = NULL;
1108	/* and getopt */
1109	#if 0 /** @todo fix getop usage! */
1110	#if defined(__FreeBSD__) \|\| defined(__EMX__) \|\| defined(__APPLE__)
1111	optreset = 1;
1112	optind = 1;
1113	#else
1114	optind = 0; /* init */
1115	#endif
1116	#endif
1117
1118	psh->exitstatus = cmdentry.u.bltin(psh, argc, argv);
1119	} else {
1120	e = psh->exception;
1121	psh->exitstatus = e == EXINT ? SIGINT + 128 :
1122	e == EXEXEC ? psh->exerrno : 2;
1123	}
1124	psh->handler = savehandler;
1125	output_flushall(psh);
1126	psh->out1 = &psh->output;
1127	psh->out2 = &psh->errout;
1128	freestdout(psh);
1129	if (temp_path) {
1130	poplocalvars(psh);
1131	psh->localvars = savelocalvars;
1132	}
1133	psh->cmdenviron = NULL;
1134	if (e != EXSHELLPROC) {
1135	psh->commandname = savecmdname;
1136	if (flags & EV_EXIT)
1137	exitshell(psh, psh->exitstatus);
1138	}
1139	if (e != -1) {
1140	if ((e != EXERROR && e != EXEXEC)
1141	\|\| cmdentry.cmdtype == CMDSPLBLTIN)
1142	exraise(psh, e);
1143	FORCEINTON;
1144	}
1145	if (cmdentry.u.bltin != execcmd)
1146	popredir(psh);
1147	if (flags == EV_BACKCMD) {
1148	backcmd->buf = psh->memout.buf;
1149	backcmd->nleft = (int)(psh->memout.nextc - psh->memout.buf);
1150	psh->memout.buf = NULL;
1151	}
1152	break;
1153
1154	default:
1155	#ifdef DEBUG
1156	trputs(psh, "normal command: "); trargs(psh, argv);
1157	#endif
1158	clearredir(psh, psh->vforked);
1159	redirect(psh, cmd->ncmd.redirect, psh->vforked ? REDIR_VFORK : 0);
1160	if (!psh->vforked)
1161	for (sp = varlist.list ; sp ; sp = sp->next)
1162	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1163	envp = environment(psh);
1164	shellexec(psh, argv, envp, path, cmdentry.u.index, psh->vforked);
1165	break;
1166	}
1167	goto out;
1168
1169	parent: /* parent process gets here (if we forked) */
1170	if (mode == FORK_FG) { /* argument to fork */
1171	psh->exitstatus = waitforjob(psh, jp);
1172	} else if (mode == FORK_NOJOB) {
1173	backcmd->fd = pip[0];
1174	shfile_close(&psh->fdtab, pip[1]);
1175	backcmd->jp = jp;
1176	}
1177	FORCEINTON;
1178
1179	out:
1180	if (lastarg)
1181	/* dsl: I think this is intended to be used to support
1182	* '_' in 'vi' command mode during line editing...
1183	* However I implemented that within libedit itself.
1184	*/
1185	setvar(psh, "_", lastarg, 0);
1186	popstackmark(psh, &smark);
1187
1188	if (eflag(psh) && psh->exitstatus && !(flags & EV_TESTED))
1189	exitshell(psh, psh->exitstatus);
1190	}
1191
1192
1193	/*
1194	* Search for a command. This is called before we fork so that the
1195	* location of the command will be available in the parent as well as
1196	* the child. The check for "goodname" is an overly conservative
1197	* check that the name will not be subject to expansion.
1198	*/
1199
1200	STATIC void
1201	prehash(shinstance psh, union node n)
1202	{
1203	struct cmdentry entry;
1204
1205	if (n->type == NCMD && n->ncmd.args)
1206	if (goodname(n->ncmd.args->narg.text))
1207	find_command(psh, n->ncmd.args->narg.text, &entry, 0,
1208	pathval(psh));
1209	}
1210
1211
1212
1213	/*
1214	* Builtin commands. Builtin commands whose functions are closely
1215	* tied to evaluation are implemented here.
1216	*/
1217
1218	/*
1219	* No command given.
1220	*/
1221
1222	int
1223	bltincmd(shinstance psh, int argc, char *argv)
1224	{
1225	/*
1226	* Preserve psh->exitstatus of a previous possible redirection
1227	* as POSIX mandates
1228	*/
1229	return psh->back_exitstatus;
1230	}
1231
1232
1233	/*
1234	* Handle break and continue commands. Break, continue, and return are
1235	* all handled by setting the psh->evalskip flag. The evaluation routines
1236	* above all check this flag, and if it is set they start skipping
1237	* commands rather than executing them. The variable skipcount is
1238	* the number of loops to break/continue, or the number of function
1239	* levels to return. (The latter is always 1.) It should probably
1240	* be an error to break out of more loops than exist, but it isn't
1241	* in the standard shell so we don't make it one here.
1242	*/
1243
1244	int
1245	breakcmd(shinstance psh, int argc, char *argv)
1246	{
1247	int n = argc > 1 ? number(psh, argv[1]) : 1;
1248
1249	if (n > psh->loopnest)
1250	n = psh->loopnest;
1251	if (n > 0) {
1252	psh->evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
1253	psh->skipcount = n;
1254	}
1255	return 0;
1256	}
1257
1258
1259	/*
1260	* The return command.
1261	*/
1262
1263	int
1264	returncmd(shinstance psh, int argc, char *argv)
1265	{
1266	#if 0
1267	int ret = argc > 1 ? number(psh, argv[1]) : psh->exitstatus;
1268	#else
1269	int ret;
1270	if (argc > 1) {
1271	/* make return -1 and VSC lite work ... */
1272	if (argv[1][0] != '-' \|\| !is_number(&argv[1][1]))
1273	ret = number(psh, argv[1]);
1274	else
1275	ret = -number(psh, &argv[1][1]) & 255; /* take the bash approach */
1276	} else {
1277	ret = psh->exitstatus;
1278	}
1279	#endif
1280
1281	if (psh->funcnest) {
1282	psh->evalskip = SKIPFUNC;
1283	psh->skipcount = 1;
1284	return ret;
1285	}
1286	else {
1287	/* Do what ksh does; skip the rest of the file */
1288	psh->evalskip = SKIPFILE;
1289	psh->skipcount = 1;
1290	return ret;
1291	}
1292	}
1293
1294
1295	int
1296	falsecmd(shinstance psh, int argc, char *argv)
1297	{
1298	return 1;
1299	}
1300
1301
1302	int
1303	truecmd(shinstance psh, int argc, char *argv)
1304	{
1305	return 0;
1306	}
1307
1308
1309	int
1310	execcmd(shinstance psh, int argc, char *argv)
1311	{
1312	if (argc > 1) {
1313	struct strlist *sp;
1314
1315	iflag(psh) = 0; /* exit on error */
1316	mflag(psh) = 0;
1317	optschanged(psh);
1318	for (sp = psh->cmdenviron; sp; sp = sp->next)
1319	setvareq(psh, sp->text, VEXPORT\|VSTACK);
1320	shellexec(psh, argv + 1, environment(psh), pathval(psh), 0, 0);
1321	}
1322	return 0;
1323	}
1324
1325	static int
1326	conv_time(clock_t ticks, char *seconds, size_t l)
1327	{
1328	static clock_t tpm = 0;
1329	clock_t mins;
1330	size_t i;
1331
1332	if (!tpm)
1333	tpm = /sysconf(_SC_CLK_TCK)/sh_sysconf_clk_tck() * 60;
1334
1335	mins = ticks / tpm;
1336	#ifdef _MSC_VER
1337	{
1338	char tmp[64];
1339	sprintf(tmp, "%.4f", (ticks - mins * tpm) * 60.0 / tpm);
1340	strlcpy(seconds, tmp, l);
1341	}
1342	#else
1343	snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
1344	#endif
1345
1346	if (seconds[0] == '6' && seconds[1] == '0') {
1347	/* 59.99995 got rounded up... */
1348	mins++;
1349	strlcpy(seconds, "0.0", l);
1350	return mins;
1351	}
1352
1353	/* suppress trailing zeros */
1354	i = strlen(seconds) - 1;
1355	for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
1356	seconds[i] = 0;
1357	return mins;
1358	}
1359
1360	int
1361	timescmd(shinstance psh, int argc, char *argv)
1362	{
1363	shtms tms;
1364	int u, s, cu, cs;
1365	char us[8], ss[8], cus[8], css[8];
1366
1367	nextopt(psh, "");
1368
1369	sh_times(psh, &tms);
1370
1371	u = conv_time(tms.tms_utime, us, sizeof(us));
1372	s = conv_time(tms.tms_stime, ss, sizeof(ss));
1373	cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
1374	cs = conv_time(tms.tms_cstime, css, sizeof(css));
1375
1376	outfmt(psh->out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
1377	u, us, s, ss, cu, cus, cs, css);
1378
1379	return 0;
1380	}

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

Download in other formats: