main.c revision 157414 
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 157414 2006-04-02 18:51:32Z stefanf $");
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 (getpwd() != NULL)
159		setvar ("PWD", getpwd(), VEXPORT);
160	if (argv[0] && argv[0][0] == '-') {
161		state = 1;
162		read_profile("/etc/profile");
163state1:
164		state = 2;
165		if (privileged == 0)
166			read_profile(".profile");
167		else
168			read_profile("/etc/suid_profile");
169	}
170state2:
171	state = 3;
172	if (!privileged && iflag) {
173		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
174			state = 3;
175			read_profile(shinit);
176		}
177	}
178state3:
179	state = 4;
180	if (minusc) {
181		evalstring(minusc);
182	}
183	if (sflag || minusc == NULL) {
184state4:	/* XXX ??? - why isn't this before the "if" statement */
185		cmdloop(1);
186	}
187	exitshell(exitstatus);
188	/*NOTREACHED*/
189	return 0;
190}
191
192
193/*
194 * Read and execute commands.  "Top" is nonzero for the top level command
195 * loop; it turns on prompting if the shell is interactive.
196 */
197
198void
199cmdloop(int top)
200{
201	union node *n;
202	struct stackmark smark;
203	int inter;
204	int numeof = 0;
205
206	TRACE(("cmdloop(%d) called\n", top));
207	setstackmark(&smark);
208	for (;;) {
209		if (pendingsigs)
210			dotrap();
211		inter = 0;
212		if (iflag && top) {
213			inter++;
214			showjobs(1, 0, 0);
215			chkmail(0);
216			flushout(&output);
217		}
218		n = parsecmd(inter);
219		/* showtree(n); DEBUG */
220		if (n == NEOF) {
221			if (!top || numeof >= 50)
222				break;
223			if (!stoppedjobs()) {
224				if (!Iflag)
225					break;
226				out2str("\nUse \"exit\" to leave shell.\n");
227			}
228			numeof++;
229		} else if (n != NULL && nflag == 0) {
230			job_warning = (job_warning == 2) ? 1 : 0;
231			numeof = 0;
232			evaltree(n, 0);
233		}
234		popstackmark(&smark);
235		setstackmark(&smark);
236		if (evalskip == SKIPFILE) {
237			evalskip = 0;
238			break;
239		}
240	}
241	popstackmark(&smark);
242}
243
244
245
246/*
247 * Read /etc/profile or .profile.  Return on error.
248 */
249
250STATIC void
251read_profile(char *name)
252{
253	int fd;
254
255	INTOFF;
256	if ((fd = open(name, O_RDONLY)) >= 0)
257		setinputfd(fd, 1);
258	INTON;
259	if (fd < 0)
260		return;
261	cmdloop(0);
262	popfile();
263}
264
265
266
267/*
268 * Read a file containing shell functions.
269 */
270
271void
272readcmdfile(char *name)
273{
274	int fd;
275
276	INTOFF;
277	if ((fd = open(name, O_RDONLY)) >= 0)
278		setinputfd(fd, 1);
279	else
280		error("Can't open %s: %s", name, strerror(errno));
281	INTON;
282	cmdloop(0);
283	popfile();
284}
285
286
287
288/*
289 * Take commands from a file.  To be compatible we should do a path
290 * search for the file, which is necessary to find sub-commands.
291 */
292
293
294STATIC char *
295find_dot_file(char *basename)
296{
297	static char localname[FILENAME_MAX+1];
298	char *fullname;
299	char *path = pathval();
300	struct stat statb;
301
302	/* don't try this for absolute or relative paths */
303	if( strchr(basename, '/'))
304		return basename;
305
306	while ((fullname = padvance(&path, basename)) != NULL) {
307		strcpy(localname, fullname);
308		stunalloc(fullname);
309		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
310			return localname;
311	}
312	return basename;
313}
314
315int
316dotcmd(int argc, char **argv)
317{
318	struct strlist *sp;
319	char *fullname;
320
321	if (argc < 2)
322		error("missing filename");
323
324	exitstatus = 0;
325
326	for (sp = cmdenviron; sp ; sp = sp->next)
327		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
328
329	fullname = find_dot_file(argv[1]);
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	extern int oexitstatus;
342
343	if (stoppedjobs())
344		return 0;
345	if (argc > 1)
346		exitstatus = number(argv[1]);
347	else
348		exitstatus = oexitstatus;
349	exitshell(exitstatus);
350	/*NOTREACHED*/
351	return 0;
352}
353