main.c revision 217175 
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 217175 2011-01-08 23:08:13Z 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		/*
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			out2fmt_flush("\n");
133		popstackmark(&smark);
134		FORCEINTON;				/* enable interrupts */
135		if (state == 1)
136			goto state1;
137		else if (state == 2)
138			goto state2;
139		else if (state == 3)
140			goto state3;
141		else
142			goto state4;
143	}
144	handler = &main_handler;
145#ifdef DEBUG
146	opentrace();
147	trputs("Shell args:  ");  trargs(argv);
148#endif
149	rootpid = getpid();
150	rootshell = 1;
151	init();
152	setstackmark(&smark);
153	procargs(argc, argv);
154	pwd_init(iflag);
155	if (iflag)
156		chkmail(1);
157	if (argv[0] && argv[0][0] == '-') {
158		state = 1;
159		read_profile("/etc/profile");
160state1:
161		state = 2;
162		if (privileged == 0)
163			read_profile(".profile");
164		else
165			read_profile("/etc/suid_profile");
166	}
167state2:
168	state = 3;
169	if (!privileged && iflag) {
170		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
171			state = 3;
172			read_profile(shinit);
173		}
174	}
175state3:
176	state = 4;
177	if (minusc) {
178		evalstring(minusc, sflag ? 0 : EV_EXIT);
179	}
180	if (sflag || minusc == NULL) {
181state4:	/* XXX ??? - why isn't this before the "if" statement */
182		cmdloop(1);
183	}
184	exitshell(exitstatus);
185	/*NOTREACHED*/
186	return 0;
187}
188
189
190/*
191 * Read and execute commands.  "Top" is nonzero for the top level command
192 * loop; it turns on prompting if the shell is interactive.
193 */
194
195void
196cmdloop(int top)
197{
198	union node *n;
199	struct stackmark smark;
200	int inter;
201	int numeof = 0;
202
203	TRACE(("cmdloop(%d) called\n", top));
204	setstackmark(&smark);
205	for (;;) {
206		if (pendingsigs)
207			dotrap();
208		inter = 0;
209		if (iflag && top) {
210			inter++;
211			showjobs(1, SHOWJOBS_DEFAULT);
212			chkmail(0);
213			flushout(&output);
214		}
215		n = parsecmd(inter);
216		/* showtree(n); DEBUG */
217		if (n == NEOF) {
218			if (!top || numeof >= 50)
219				break;
220			if (!stoppedjobs()) {
221				if (!Iflag)
222					break;
223				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
224			}
225			numeof++;
226		} else if (n != NULL && nflag == 0) {
227			job_warning = (job_warning == 2) ? 1 : 0;
228			numeof = 0;
229			evaltree(n, 0);
230		}
231		popstackmark(&smark);
232		setstackmark(&smark);
233		if (evalskip != 0) {
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(const 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(const 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	const 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	char *filename, *fullname;
317
318	if (argc < 2)
319		error("missing filename");
320
321	exitstatus = 0;
322
323	/*
324	 * Because we have historically not supported any options,
325	 * only treat "--" specially.
326	 */
327	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
328
329	fullname = find_dot_file(filename);
330	setinputfile(fullname, 1);
331	commandname = fullname;
332	cmdloop(0);
333	popfile();
334	return exitstatus;
335}
336
337
338int
339exitcmd(int argc, char **argv)
340{
341	if (stoppedjobs())
342		return 0;
343	if (argc > 1)
344		exitshell(number(argv[1]));
345	else
346		exitshell_savedstatus();
347}
348