main.c revision 218306 
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 218306 2011-02-04 22:47:55Z 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			exitshell(exitstatus);
116		reset();
117		if (exception == EXINT)
118			out2fmt_flush("\n");
119		popstackmark(&smark);
120		FORCEINTON;				/* enable interrupts */
121		if (state == 1)
122			goto state1;
123		else if (state == 2)
124			goto state2;
125		else if (state == 3)
126			goto state3;
127		else
128			goto state4;
129	}
130	handler = &main_handler;
131#ifdef DEBUG
132	opentrace();
133	trputs("Shell args:  ");  trargs(argv);
134#endif
135	rootpid = getpid();
136	rootshell = 1;
137	init();
138	setstackmark(&smark);
139	procargs(argc, argv);
140	pwd_init(iflag);
141	if (iflag)
142		chkmail(1);
143	if (argv[0] && argv[0][0] == '-') {
144		state = 1;
145		read_profile("/etc/profile");
146state1:
147		state = 2;
148		if (privileged == 0)
149			read_profile(".profile");
150		else
151			read_profile("/etc/suid_profile");
152	}
153state2:
154	state = 3;
155	if (!privileged && iflag) {
156		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
157			state = 3;
158			read_profile(shinit);
159		}
160	}
161state3:
162	state = 4;
163	if (minusc) {
164		evalstring(minusc, sflag ? 0 : EV_EXIT);
165	}
166	if (sflag || minusc == NULL) {
167state4:	/* XXX ??? - why isn't this before the "if" statement */
168		cmdloop(1);
169	}
170	exitshell(exitstatus);
171	/*NOTREACHED*/
172	return 0;
173}
174
175
176/*
177 * Read and execute commands.  "Top" is nonzero for the top level command
178 * loop; it turns on prompting if the shell is interactive.
179 */
180
181void
182cmdloop(int top)
183{
184	union node *n;
185	struct stackmark smark;
186	int inter;
187	int numeof = 0;
188
189	TRACE(("cmdloop(%d) called\n", top));
190	setstackmark(&smark);
191	for (;;) {
192		if (pendingsigs)
193			dotrap();
194		inter = 0;
195		if (iflag && top) {
196			inter++;
197			showjobs(1, SHOWJOBS_DEFAULT);
198			chkmail(0);
199			flushout(&output);
200		}
201		n = parsecmd(inter);
202		/* showtree(n); DEBUG */
203		if (n == NEOF) {
204			if (!top || numeof >= 50)
205				break;
206			if (!stoppedjobs()) {
207				if (!Iflag)
208					break;
209				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
210			}
211			numeof++;
212		} else if (n != NULL && nflag == 0) {
213			job_warning = (job_warning == 2) ? 1 : 0;
214			numeof = 0;
215			evaltree(n, 0);
216		}
217		popstackmark(&smark);
218		setstackmark(&smark);
219		if (evalskip != 0) {
220			if (evalskip == SKIPFILE)
221				evalskip = 0;
222			break;
223		}
224	}
225	popstackmark(&smark);
226}
227
228
229
230/*
231 * Read /etc/profile or .profile.  Return on error.
232 */
233
234static void
235read_profile(const char *name)
236{
237	int fd;
238
239	INTOFF;
240	if ((fd = open(name, O_RDONLY)) >= 0)
241		setinputfd(fd, 1);
242	INTON;
243	if (fd < 0)
244		return;
245	cmdloop(0);
246	popfile();
247}
248
249
250
251/*
252 * Read a file containing shell functions.
253 */
254
255void
256readcmdfile(const char *name)
257{
258	int fd;
259
260	INTOFF;
261	if ((fd = open(name, O_RDONLY)) >= 0)
262		setinputfd(fd, 1);
263	else
264		error("Can't open %s: %s", name, strerror(errno));
265	INTON;
266	cmdloop(0);
267	popfile();
268}
269
270
271
272/*
273 * Take commands from a file.  To be compatible we should do a path
274 * search for the file, which is necessary to find sub-commands.
275 */
276
277
278static char *
279find_dot_file(char *basename)
280{
281	static char localname[FILENAME_MAX+1];
282	char *fullname;
283	const char *path = pathval();
284	struct stat statb;
285
286	/* don't try this for absolute or relative paths */
287	if( strchr(basename, '/'))
288		return basename;
289
290	while ((fullname = padvance(&path, basename)) != NULL) {
291		strcpy(localname, fullname);
292		stunalloc(fullname);
293		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
294			return localname;
295	}
296	return basename;
297}
298
299int
300dotcmd(int argc, char **argv)
301{
302	char *filename, *fullname;
303
304	if (argc < 2)
305		error("missing filename");
306
307	exitstatus = 0;
308
309	/*
310	 * Because we have historically not supported any options,
311	 * only treat "--" specially.
312	 */
313	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
314
315	fullname = find_dot_file(filename);
316	setinputfile(fullname, 1);
317	commandname = fullname;
318	cmdloop(0);
319	popfile();
320	return exitstatus;
321}
322
323
324int
325exitcmd(int argc, char **argv)
326{
327	if (stoppedjobs())
328		return 0;
329	if (argc > 1)
330		exitshell(number(argv[1]));
331	else
332		exitshell_savedstatus();
333}
334