main.c revision 99110 
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 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38static char const copyright[] =
39"@(#) Copyright (c) 1991, 1993\n\
40	The Regents of the University of California.  All rights reserved.\n";
41#endif /* not lint */
42
43#ifndef lint
44#if 0
45static char sccsid[] = "@(#)main.c	8.6 (Berkeley) 5/28/95";
46#endif
47#endif /* not lint */
48#include <sys/cdefs.h>
49__FBSDID("$FreeBSD: head/bin/sh/main.c 99110 2002-06-30 05:15:05Z obrien $");
50
51#include <stdio.h>
52#include <signal.h>
53#include <sys/stat.h>
54#include <unistd.h>
55#include <fcntl.h>
56#include <locale.h>
57#include <errno.h>
58
59#include "shell.h"
60#include "main.h"
61#include "mail.h"
62#include "options.h"
63#include "output.h"
64#include "parser.h"
65#include "nodes.h"
66#include "expand.h"
67#include "eval.h"
68#include "jobs.h"
69#include "input.h"
70#include "trap.h"
71#include "var.h"
72#include "show.h"
73#include "memalloc.h"
74#include "error.h"
75#include "init.h"
76#include "mystring.h"
77#include "exec.h"
78#include "cd.h"
79
80#define PROFILE 0
81
82int rootpid;
83int rootshell;
84#if PROFILE
85short profile_buf[16384];
86extern int etext();
87#endif
88
89STATIC void read_profile(char *);
90STATIC char *find_dot_file(char *);
91
92/*
93 * Main routine.  We initialize things, parse the arguments, execute
94 * profiles if we're a login shell, and then call cmdloop to execute
95 * commands.  The setjmp call sets up the location to jump to when an
96 * exception occurs.  When an exception occurs the variable "state"
97 * is used to figure out how far we had gotten.
98 */
99
100int
101main(int argc, char *argv[])
102{
103	struct jmploc jmploc;
104	struct stackmark smark;
105	volatile int state;
106	char *shinit;
107
108#if PROFILE
109	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
110#endif
111	(void) setlocale(LC_ALL, "");
112	state = 0;
113	if (setjmp(jmploc.loc)) {
114		/*
115		 * When a shell procedure is executed, we raise the
116		 * exception EXSHELLPROC to clean up before executing
117		 * the shell procedure.
118		 */
119		switch (exception) {
120		case EXSHELLPROC:
121			rootpid = getpid();
122			rootshell = 1;
123			minusc = NULL;
124			state = 3;
125			break;
126
127		case EXEXEC:
128			exitstatus = exerrno;
129			break;
130
131		case EXERROR:
132			exitstatus = 2;
133			break;
134
135		default:
136			break;
137		}
138
139		if (exception != EXSHELLPROC) {
140		    if (state == 0 || iflag == 0 || ! rootshell)
141			    exitshell(exitstatus);
142		}
143		reset();
144		if (exception == EXINT
145#if ATTY
146		 && (! attyset() || equal(termval(), "emacs"))
147#endif
148		 ) {
149			out2c('\n');
150			flushout(&errout);
151		}
152		popstackmark(&smark);
153		FORCEINTON;				/* enable interrupts */
154		if (state == 1)
155			goto state1;
156		else if (state == 2)
157			goto state2;
158		else if (state == 3)
159			goto state3;
160		else
161			goto state4;
162	}
163	handler = &jmploc;
164#ifdef DEBUG
165	opentrace();
166	trputs("Shell args:  ");  trargs(argv);
167#endif
168	rootpid = getpid();
169	rootshell = 1;
170	init();
171	setstackmark(&smark);
172	procargs(argc, argv);
173	if (getpwd() == NULL && iflag)
174		out2str("sh: cannot determine working directory\n");
175	if (argv[0] && argv[0][0] == '-') {
176		state = 1;
177		read_profile("/etc/profile");
178state1:
179		state = 2;
180		if (privileged == 0)
181			read_profile(".profile");
182		else
183			read_profile("/etc/suid_profile");
184	}
185state2:
186	state = 3;
187	if (!privileged && iflag) {
188		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
189			state = 3;
190			read_profile(shinit);
191		}
192	}
193state3:
194	state = 4;
195	if (minusc) {
196		evalstring(minusc);
197	}
198	if (sflag || minusc == NULL) {
199state4:	/* XXX ??? - why isn't this before the "if" statement */
200		cmdloop(1);
201	}
202#if PROFILE
203	monitor(0);
204#endif
205	exitshell(exitstatus);
206	/*NOTREACHED*/
207	return 0;
208}
209
210
211/*
212 * Read and execute commands.  "Top" is nonzero for the top level command
213 * loop; it turns on prompting if the shell is interactive.
214 */
215
216void
217cmdloop(int top)
218{
219	union node *n;
220	struct stackmark smark;
221	int inter;
222	int numeof = 0;
223
224	TRACE(("cmdloop(%d) called\n", top));
225	setstackmark(&smark);
226	for (;;) {
227		if (pendingsigs)
228			dotrap();
229		inter = 0;
230		if (iflag && top) {
231			inter++;
232			showjobs(1, 0, 0);
233			chkmail(0);
234			flushout(&output);
235		}
236		n = parsecmd(inter);
237		/* showtree(n); DEBUG */
238		if (n == NEOF) {
239			if (!top || numeof >= 50)
240				break;
241			if (!stoppedjobs()) {
242				if (!Iflag)
243					break;
244				out2str("\nUse \"exit\" to leave shell.\n");
245			}
246			numeof++;
247		} else if (n != NULL && nflag == 0) {
248			job_warning = (job_warning == 2) ? 1 : 0;
249			numeof = 0;
250			evaltree(n, 0);
251		}
252		popstackmark(&smark);
253		setstackmark(&smark);
254		if (evalskip == SKIPFILE) {
255			evalskip = 0;
256			break;
257		}
258	}
259	popstackmark(&smark);
260}
261
262
263
264/*
265 * Read /etc/profile or .profile.  Return on error.
266 */
267
268STATIC void
269read_profile(char *name)
270{
271	int fd;
272
273	INTOFF;
274	if ((fd = open(name, O_RDONLY)) >= 0)
275		setinputfd(fd, 1);
276	INTON;
277	if (fd < 0)
278		return;
279	cmdloop(0);
280	popfile();
281}
282
283
284
285/*
286 * Read a file containing shell functions.
287 */
288
289void
290readcmdfile(char *name)
291{
292	int fd;
293
294	INTOFF;
295	if ((fd = open(name, O_RDONLY)) >= 0)
296		setinputfd(fd, 1);
297	else
298		error("Can't open %s: %s", name, strerror(errno));
299	INTON;
300	cmdloop(0);
301	popfile();
302}
303
304
305
306/*
307 * Take commands from a file.  To be compatible we should do a path
308 * search for the file, which is necessary to find sub-commands.
309 */
310
311
312STATIC char *
313find_dot_file(char *basename)
314{
315	static char localname[FILENAME_MAX+1];
316	char *fullname;
317	char *path = pathval();
318	struct stat statb;
319
320	/* don't try this for absolute or relative paths */
321	if( strchr(basename, '/'))
322		return basename;
323
324	while ((fullname = padvance(&path, basename)) != NULL) {
325		strcpy(localname, fullname);
326		stunalloc(fullname);
327		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
328			return localname;
329	}
330	return basename;
331}
332
333int
334dotcmd(int argc, char **argv)
335{
336	struct strlist *sp;
337	exitstatus = 0;
338
339	for (sp = cmdenviron; sp ; sp = sp->next)
340		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
341
342	if (argc >= 2) {		/* That's what SVR2 does */
343		char *fullname = find_dot_file(argv[1]);
344
345		setinputfile(fullname, 1);
346		commandname = fullname;
347		cmdloop(0);
348		popfile();
349	}
350	return exitstatus;
351}
352
353
354int
355exitcmd(int argc, char **argv)
356{
357	extern int oexitstatus;
358
359	if (stoppedjobs())
360		return 0;
361	if (argc > 1)
362		exitstatus = number(argv[1]);
363	else
364		exitstatus = oexitstatus;
365	exitshell(exitstatus);
366	/*NOTREACHED*/
367	return 0;
368}
369