main.c revision 220978 
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 220978 2011-04-23 22:28:56Z jilles $");
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;
78struct jmploc main_handler;
79
80static void read_profile(const char *);
81static char *find_dot_file(char *);
82
83/*
84 * Main routine.  We initialize things, parse the arguments, execute
85 * profiles if we're a login shell, and then call cmdloop to execute
86 * commands.  The setjmp call sets up the location to jump to when an
87 * exception occurs.  When an exception occurs the variable "state"
88 * is used to figure out how far we had gotten.
89 */
90
91int
92main(int argc, char *argv[])
93{
94	struct stackmark smark;
95	volatile int state;
96	char *shinit;
97
98	(void) setlocale(LC_ALL, "");
99	state = 0;
100	if (setjmp(main_handler.loc)) {
101		switch (exception) {
102		case EXEXEC:
103			exitstatus = exerrno;
104			break;
105
106		case EXERROR:
107			exitstatus = 2;
108			break;
109
110		default:
111			break;
112		}
113
114		if (state == 0 || iflag == 0 || ! rootshell ||
115		    exception == EXEXIT)
116			exitshell(exitstatus);
117		reset();
118		if (exception == EXINT)
119			out2fmt_flush("\n");
120		popstackmark(&smark);
121		FORCEINTON;				/* enable interrupts */
122		if (state == 1)
123			goto state1;
124		else if (state == 2)
125			goto state2;
126		else if (state == 3)
127			goto state3;
128		else
129			goto state4;
130	}
131	handler = &main_handler;
132#ifdef DEBUG
133	opentrace();
134	trputs("Shell args:  ");  trargs(argv);
135#endif
136	rootpid = getpid();
137	rootshell = 1;
138	init();
139	setstackmark(&smark);
140	procargs(argc, argv);
141	pwd_init(iflag);
142	if (iflag)
143		chkmail(1);
144	if (argv[0] && argv[0][0] == '-') {
145		state = 1;
146		read_profile("/etc/profile");
147state1:
148		state = 2;
149		if (privileged == 0)
150			read_profile(".profile");
151		else
152			read_profile("/etc/suid_profile");
153	}
154state2:
155	state = 3;
156	if (!privileged && iflag) {
157		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
158			state = 3;
159			read_profile(shinit);
160		}
161	}
162state3:
163	state = 4;
164	if (minusc) {
165		evalstring(minusc, sflag ? 0 : EV_EXIT);
166	}
167	if (sflag || minusc == NULL) {
168state4:	/* XXX ??? - why isn't this before the "if" statement */
169		cmdloop(1);
170	}
171	exitshell(exitstatus);
172	/*NOTREACHED*/
173	return 0;
174}
175
176
177/*
178 * Read and execute commands.  "Top" is nonzero for the top level command
179 * loop; it turns on prompting if the shell is interactive.
180 */
181
182void
183cmdloop(int top)
184{
185	union node *n;
186	struct stackmark smark;
187	int inter;
188	int numeof = 0;
189
190	TRACE(("cmdloop(%d) called\n", top));
191	setstackmark(&smark);
192	for (;;) {
193		if (pendingsigs)
194			dotrap();
195		inter = 0;
196		if (iflag && top) {
197			inter++;
198			showjobs(1, SHOWJOBS_DEFAULT);
199			chkmail(0);
200			flushout(&output);
201		}
202		n = parsecmd(inter);
203		/* showtree(n); DEBUG */
204		if (n == NEOF) {
205			if (!top || numeof >= 50)
206				break;
207			if (!stoppedjobs()) {
208				if (!Iflag)
209					break;
210				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
211			}
212			numeof++;
213		} else if (n != NULL && nflag == 0) {
214			job_warning = (job_warning == 2) ? 1 : 0;
215			numeof = 0;
216			evaltree(n, 0);
217		}
218		popstackmark(&smark);
219		setstackmark(&smark);
220		if (evalskip != 0) {
221			if (evalskip == SKIPFILE)
222				evalskip = 0;
223			break;
224		}
225	}
226	popstackmark(&smark);
227}
228
229
230
231/*
232 * Read /etc/profile or .profile.  Return on error.
233 */
234
235static void
236read_profile(const char *name)
237{
238	int fd;
239
240	INTOFF;
241	if ((fd = open(name, O_RDONLY)) >= 0)
242		setinputfd(fd, 1);
243	INTON;
244	if (fd < 0)
245		return;
246	cmdloop(0);
247	popfile();
248}
249
250
251
252/*
253 * Read a file containing shell functions.
254 */
255
256void
257readcmdfile(const char *name)
258{
259	int fd;
260
261	INTOFF;
262	if ((fd = open(name, O_RDONLY)) >= 0)
263		setinputfd(fd, 1);
264	else
265		error("Can't open %s: %s", name, strerror(errno));
266	INTON;
267	cmdloop(0);
268	popfile();
269}
270
271
272
273/*
274 * Take commands from a file.  To be compatible we should do a path
275 * search for the file, which is necessary to find sub-commands.
276 */
277
278
279static char *
280find_dot_file(char *basename)
281{
282	static char localname[FILENAME_MAX+1];
283	char *fullname;
284	const char *path = pathval();
285	struct stat statb;
286
287	/* don't try this for absolute or relative paths */
288	if( strchr(basename, '/'))
289		return basename;
290
291	while ((fullname = padvance(&path, basename)) != NULL) {
292		strcpy(localname, fullname);
293		stunalloc(fullname);
294		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
295			return localname;
296	}
297	return basename;
298}
299
300int
301dotcmd(int argc, char **argv)
302{
303	char *filename, *fullname;
304
305	if (argc < 2)
306		error("missing filename");
307
308	exitstatus = 0;
309
310	/*
311	 * Because we have historically not supported any options,
312	 * only treat "--" specially.
313	 */
314	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
315
316	fullname = find_dot_file(filename);
317	setinputfile(fullname, 1);
318	commandname = fullname;
319	cmdloop(0);
320	popfile();
321	return exitstatus;
322}
323
324
325int
326exitcmd(int argc, char **argv)
327{
328	if (stoppedjobs())
329		return 0;
330	if (argc > 1)
331		exitshell(number(argv[1]));
332	else
333		exitshell_savedstatus();
334}
335