main.c revision 127958 
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 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34static char const copyright[] =
35"@(#) Copyright (c) 1991, 1993\n\
36	The Regents of the University of California.  All rights reserved.\n";
37#endif /* not lint */
38
39#ifndef lint
40#if 0
41static char sccsid[] = "@(#)main.c	8.6 (Berkeley) 5/28/95";
42#endif
43#endif /* not lint */
44#include <sys/cdefs.h>
45__FBSDID("$FreeBSD: head/bin/sh/main.c 127958 2004-04-06 20:06:54Z markm $");
46
47#include <stdio.h>
48#include <signal.h>
49#include <sys/stat.h>
50#include <unistd.h>
51#include <fcntl.h>
52#include <locale.h>
53#include <errno.h>
54
55#include "shell.h"
56#include "main.h"
57#include "mail.h"
58#include "options.h"
59#include "output.h"
60#include "parser.h"
61#include "nodes.h"
62#include "expand.h"
63#include "eval.h"
64#include "jobs.h"
65#include "input.h"
66#include "trap.h"
67#include "var.h"
68#include "show.h"
69#include "memalloc.h"
70#include "error.h"
71#include "init.h"
72#include "mystring.h"
73#include "exec.h"
74#include "cd.h"
75
76int rootpid;
77int rootshell;
78
79STATIC void read_profile(char *);
80STATIC char *find_dot_file(char *);
81
82/*
83 * Main routine.  We initialize things, parse the arguments, execute
84 * profiles if we're a login shell, and then call cmdloop to execute
85 * commands.  The setjmp call sets up the location to jump to when an
86 * exception occurs.  When an exception occurs the variable "state"
87 * is used to figure out how far we had gotten.
88 */
89
90int
91main(int argc, char *argv[])
92{
93	struct jmploc jmploc;
94	struct stackmark smark;
95	volatile int state;
96	char *shinit;
97
98	(void) setlocale(LC_ALL, "");
99	state = 0;
100	if (setjmp(jmploc.loc)) {
101		/*
102		 * When a shell procedure is executed, we raise the
103		 * exception EXSHELLPROC to clean up before executing
104		 * the shell procedure.
105		 */
106		switch (exception) {
107		case EXSHELLPROC:
108			rootpid = getpid();
109			rootshell = 1;
110			minusc = NULL;
111			state = 3;
112			break;
113
114		case EXEXEC:
115			exitstatus = exerrno;
116			break;
117
118		case EXERROR:
119			exitstatus = 2;
120			break;
121
122		default:
123			break;
124		}
125
126		if (exception != EXSHELLPROC) {
127		    if (state == 0 || iflag == 0 || ! rootshell)
128			    exitshell(exitstatus);
129		}
130		reset();
131		if (exception == EXINT) {
132			out2c('\n');
133			flushout(&errout);
134		}
135		popstackmark(&smark);
136		FORCEINTON;				/* enable interrupts */
137		if (state == 1)
138			goto state1;
139		else if (state == 2)
140			goto state2;
141		else if (state == 3)
142			goto state3;
143		else
144			goto state4;
145	}
146	handler = &jmploc;
147#ifdef DEBUG
148	opentrace();
149	trputs("Shell args:  ");  trargs(argv);
150#endif
151	rootpid = getpid();
152	rootshell = 1;
153	init();
154	setstackmark(&smark);
155	procargs(argc, argv);
156	if (getpwd() == NULL && iflag)
157		out2str("sh: cannot determine working directory\n");
158	if (argv[0] && argv[0][0] == '-') {
159		state = 1;
160		read_profile("/etc/profile");
161state1:
162		state = 2;
163		if (privileged == 0)
164			read_profile(".profile");
165		else
166			read_profile("/etc/suid_profile");
167	}
168state2:
169	state = 3;
170	if (!privileged && iflag) {
171		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
172			state = 3;
173			read_profile(shinit);
174		}
175	}
176state3:
177	state = 4;
178	if (minusc) {
179		evalstring(minusc);
180	}
181	if (sflag || minusc == NULL) {
182state4:	/* XXX ??? - why isn't this before the "if" statement */
183		cmdloop(1);
184	}
185	exitshell(exitstatus);
186	/*NOTREACHED*/
187	return 0;
188}
189
190
191/*
192 * Read and execute commands.  "Top" is nonzero for the top level command
193 * loop; it turns on prompting if the shell is interactive.
194 */
195
196void
197cmdloop(int top)
198{
199	union node *n;
200	struct stackmark smark;
201	int inter;
202	int numeof = 0;
203
204	TRACE(("cmdloop(%d) called\n", top));
205	setstackmark(&smark);
206	for (;;) {
207		if (pendingsigs)
208			dotrap();
209		inter = 0;
210		if (iflag && top) {
211			inter++;
212			showjobs(1, 0, 0);
213			chkmail(0);
214			flushout(&output);
215		}
216		n = parsecmd(inter);
217		/* showtree(n); DEBUG */
218		if (n == NEOF) {
219			if (!top || numeof >= 50)
220				break;
221			if (!stoppedjobs()) {
222				if (!Iflag)
223					break;
224				out2str("\nUse \"exit\" to leave shell.\n");
225			}
226			numeof++;
227		} else if (n != NULL && nflag == 0) {
228			job_warning = (job_warning == 2) ? 1 : 0;
229			numeof = 0;
230			evaltree(n, 0);
231		}
232		popstackmark(&smark);
233		setstackmark(&smark);
234		if (evalskip == SKIPFILE) {
235			evalskip = 0;
236			break;
237		}
238	}
239	popstackmark(&smark);
240}
241
242
243
244/*
245 * Read /etc/profile or .profile.  Return on error.
246 */
247
248STATIC void
249read_profile(char *name)
250{
251	int fd;
252
253	INTOFF;
254	if ((fd = open(name, O_RDONLY)) >= 0)
255		setinputfd(fd, 1);
256	INTON;
257	if (fd < 0)
258		return;
259	cmdloop(0);
260	popfile();
261}
262
263
264
265/*
266 * Read a file containing shell functions.
267 */
268
269void
270readcmdfile(char *name)
271{
272	int fd;
273
274	INTOFF;
275	if ((fd = open(name, O_RDONLY)) >= 0)
276		setinputfd(fd, 1);
277	else
278		error("Can't open %s: %s", name, strerror(errno));
279	INTON;
280	cmdloop(0);
281	popfile();
282}
283
284
285
286/*
287 * Take commands from a file.  To be compatible we should do a path
288 * search for the file, which is necessary to find sub-commands.
289 */
290
291
292STATIC char *
293find_dot_file(char *basename)
294{
295	static char localname[FILENAME_MAX+1];
296	char *fullname;
297	char *path = pathval();
298	struct stat statb;
299
300	/* don't try this for absolute or relative paths */
301	if( strchr(basename, '/'))
302		return basename;
303
304	while ((fullname = padvance(&path, basename)) != NULL) {
305		strcpy(localname, fullname);
306		stunalloc(fullname);
307		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
308			return localname;
309	}
310	return basename;
311}
312
313int
314dotcmd(int argc, char **argv)
315{
316	struct strlist *sp;
317	exitstatus = 0;
318
319	for (sp = cmdenviron; sp ; sp = sp->next)
320		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
321
322	if (argc >= 2) {		/* That's what SVR2 does */
323		char *fullname = find_dot_file(argv[1]);
324
325		setinputfile(fullname, 1);
326		commandname = fullname;
327		cmdloop(0);
328		popfile();
329	}
330	return exitstatus;
331}
332
333
334int
335exitcmd(int argc, char **argv)
336{
337	extern int oexitstatus;
338
339	if (stoppedjobs())
340		return 0;
341	if (argc > 1)
342		exitstatus = number(argv[1]);
343	else
344		exitstatus = oexitstatus;
345	exitshell(exitstatus);
346	/*NOTREACHED*/
347	return 0;
348}
349