main.c revision 104255 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38static char const copyright[] =
39"@(#) Copyright (c) 1991, 1993\n\
40	The Regents of the University of California.  All rights reserved.\n";
41#endif /* not lint */
42
43#ifndef lint
44#if 0
45static char sccsid[] = "@(#)main.c	8.6 (Berkeley) 5/28/95";
46#endif
47#endif /* not lint */
48#include <sys/cdefs.h>
49__FBSDID("$FreeBSD: head/bin/sh/main.c 104255 2002-10-01 00:54:14Z tjr $");
50
51#include <stdio.h>
52#include <signal.h>
53#include <sys/stat.h>
54#include <unistd.h>
55#include <fcntl.h>
56#include <locale.h>
57#include <errno.h>
58
59#include "shell.h"
60#include "main.h"
61#include "mail.h"
62#include "options.h"
63#include "output.h"
64#include "parser.h"
65#include "nodes.h"
66#include "expand.h"
67#include "eval.h"
68#include "jobs.h"
69#include "input.h"
70#include "trap.h"
71#include "var.h"
72#include "show.h"
73#include "memalloc.h"
74#include "error.h"
75#include "init.h"
76#include "mystring.h"
77#include "exec.h"
78#include "cd.h"
79
80#define PROFILE 0
81
82int rootpid;
83int rootshell;
84#if PROFILE
85short profile_buf[16384];
86extern int etext();
87#endif
88
89STATIC void read_profile(char *);
90STATIC char *find_dot_file(char *);
91
92/*
93 * Main routine.  We initialize things, parse the arguments, execute
94 * profiles if we're a login shell, and then call cmdloop to execute
95 * commands.  The setjmp call sets up the location to jump to when an
96 * exception occurs.  When an exception occurs the variable "state"
97 * is used to figure out how far we had gotten.
98 */
99
100int
101main(int argc, char *argv[])
102{
103	struct jmploc jmploc;
104	struct stackmark smark;
105	volatile int state;
106	char *shinit;
107
108#if PROFILE
109	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
110#endif
111	(void) setlocale(LC_ALL, "");
112	state = 0;
113	if (setjmp(jmploc.loc)) {
114		/*
115		 * When a shell procedure is executed, we raise the
116		 * exception EXSHELLPROC to clean up before executing
117		 * the shell procedure.
118		 */
119		switch (exception) {
120		case EXSHELLPROC:
121			rootpid = getpid();
122			rootshell = 1;
123			minusc = NULL;
124			state = 3;
125			break;
126
127		case EXEXEC:
128			exitstatus = exerrno;
129			break;
130
131		case EXERROR:
132			exitstatus = 2;
133			break;
134
135		default:
136			break;
137		}
138
139		if (exception != EXSHELLPROC) {
140		    if (state == 0 || iflag == 0 || ! rootshell)
141			    exitshell(exitstatus);
142		}
143		reset();
144		if (exception == EXINT) {
145			out2c('\n');
146			flushout(&errout);
147		}
148		popstackmark(&smark);
149		FORCEINTON;				/* enable interrupts */
150		if (state == 1)
151			goto state1;
152		else if (state == 2)
153			goto state2;
154		else if (state == 3)
155			goto state3;
156		else
157			goto state4;
158	}
159	handler = &jmploc;
160#ifdef DEBUG
161	opentrace();
162	trputs("Shell args:  ");  trargs(argv);
163#endif
164	rootpid = getpid();
165	rootshell = 1;
166	init();
167	setstackmark(&smark);
168	procargs(argc, argv);
169	if (getpwd() == NULL && iflag)
170		out2str("sh: cannot determine working directory\n");
171	if (argv[0] && argv[0][0] == '-') {
172		state = 1;
173		read_profile("/etc/profile");
174state1:
175		state = 2;
176		if (privileged == 0)
177			read_profile(".profile");
178		else
179			read_profile("/etc/suid_profile");
180	}
181state2:
182	state = 3;
183	if (!privileged && iflag) {
184		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
185			state = 3;
186			read_profile(shinit);
187		}
188	}
189state3:
190	state = 4;
191	if (minusc) {
192		evalstring(minusc);
193	}
194	if (sflag || minusc == NULL) {
195state4:	/* XXX ??? - why isn't this before the "if" statement */
196		cmdloop(1);
197	}
198#if PROFILE
199	monitor(0);
200#endif
201	exitshell(exitstatus);
202	/*NOTREACHED*/
203	return 0;
204}
205
206
207/*
208 * Read and execute commands.  "Top" is nonzero for the top level command
209 * loop; it turns on prompting if the shell is interactive.
210 */
211
212void
213cmdloop(int top)
214{
215	union node *n;
216	struct stackmark smark;
217	int inter;
218	int numeof = 0;
219
220	TRACE(("cmdloop(%d) called\n", top));
221	setstackmark(&smark);
222	for (;;) {
223		if (pendingsigs)
224			dotrap();
225		inter = 0;
226		if (iflag && top) {
227			inter++;
228			showjobs(1, 0, 0);
229			chkmail(0);
230			flushout(&output);
231		}
232		n = parsecmd(inter);
233		/* showtree(n); DEBUG */
234		if (n == NEOF) {
235			if (!top || numeof >= 50)
236				break;
237			if (!stoppedjobs()) {
238				if (!Iflag)
239					break;
240				out2str("\nUse \"exit\" to leave shell.\n");
241			}
242			numeof++;
243		} else if (n != NULL && nflag == 0) {
244			job_warning = (job_warning == 2) ? 1 : 0;
245			numeof = 0;
246			evaltree(n, 0);
247		}
248		popstackmark(&smark);
249		setstackmark(&smark);
250		if (evalskip == SKIPFILE) {
251			evalskip = 0;
252			break;
253		}
254	}
255	popstackmark(&smark);
256}
257
258
259
260/*
261 * Read /etc/profile or .profile.  Return on error.
262 */
263
264STATIC void
265read_profile(char *name)
266{
267	int fd;
268
269	INTOFF;
270	if ((fd = open(name, O_RDONLY)) >= 0)
271		setinputfd(fd, 1);
272	INTON;
273	if (fd < 0)
274		return;
275	cmdloop(0);
276	popfile();
277}
278
279
280
281/*
282 * Read a file containing shell functions.
283 */
284
285void
286readcmdfile(char *name)
287{
288	int fd;
289
290	INTOFF;
291	if ((fd = open(name, O_RDONLY)) >= 0)
292		setinputfd(fd, 1);
293	else
294		error("Can't open %s: %s", name, strerror(errno));
295	INTON;
296	cmdloop(0);
297	popfile();
298}
299
300
301
302/*
303 * Take commands from a file.  To be compatible we should do a path
304 * search for the file, which is necessary to find sub-commands.
305 */
306
307
308STATIC char *
309find_dot_file(char *basename)
310{
311	static char localname[FILENAME_MAX+1];
312	char *fullname;
313	char *path = pathval();
314	struct stat statb;
315
316	/* don't try this for absolute or relative paths */
317	if( strchr(basename, '/'))
318		return basename;
319
320	while ((fullname = padvance(&path, basename)) != NULL) {
321		strcpy(localname, fullname);
322		stunalloc(fullname);
323		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
324			return localname;
325	}
326	return basename;
327}
328
329int
330dotcmd(int argc, char **argv)
331{
332	struct strlist *sp;
333	exitstatus = 0;
334
335	for (sp = cmdenviron; sp ; sp = sp->next)
336		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
337
338	if (argc >= 2) {		/* That's what SVR2 does */
339		char *fullname = find_dot_file(argv[1]);
340
341		setinputfile(fullname, 1);
342		commandname = fullname;
343		cmdloop(0);
344		popfile();
345	}
346	return exitstatus;
347}
348
349
350int
351exitcmd(int argc, char **argv)
352{
353	extern int oexitstatus;
354
355	if (stoppedjobs())
356		return 0;
357	if (argc > 1)
358		exitstatus = number(argv[1]);
359	else
360		exitstatus = oexitstatus;
361	exitshell(exitstatus);
362	/*NOTREACHED*/
363	return 0;
364}
365