main.c revision 36150 
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
47static const char rcsid[] =
48	"$Id$";
49#endif /* not lint */
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
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;
84extern int errno;
85#if PROFILE
86short profile_buf[16384];
87extern int etext();
88#endif
89
90STATIC void read_profile __P((char *));
91STATIC char *find_dot_file __P((char *));
92
93/*
94 * Main routine.  We initialize things, parse the arguments, execute
95 * profiles if we're a login shell, and then call cmdloop to execute
96 * commands.  The setjmp call sets up the location to jump to when an
97 * exception occurs.  When an exception occurs the variable "state"
98 * is used to figure out how far we had gotten.
99 */
100
101int
102main(argc, argv)
103	int argc;
104	char **argv;
105{
106	struct jmploc jmploc;
107	struct stackmark smark;
108	volatile int state;
109	char *shinit;
110
111#if PROFILE
112	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
113#endif
114	(void) setlocale(LC_ALL, "");
115	state = 0;
116	if (setjmp(jmploc.loc)) {
117		/*
118		 * When a shell procedure is executed, we raise the
119		 * exception EXSHELLPROC to clean up before executing
120		 * the shell procedure.
121		 */
122		switch (exception) {
123		case EXSHELLPROC:
124			rootpid = getpid();
125			rootshell = 1;
126			minusc = NULL;
127			state = 3;
128			break;
129
130		case EXEXEC:
131			exitstatus = exerrno;
132			break;
133
134		case EXERROR:
135			exitstatus = 2;
136			break;
137
138		default:
139			break;
140		}
141
142		if (exception != EXSHELLPROC) {
143		    if (state == 0 || iflag == 0 || ! rootshell)
144			    exitshell(exitstatus);
145		}
146		reset();
147		if (exception == EXINT
148#if ATTY
149		 && (! attyset() || equal(termval(), "emacs"))
150#endif
151		 ) {
152			out2c('\n');
153			flushout(&errout);
154		}
155		popstackmark(&smark);
156		FORCEINTON;				/* enable interrupts */
157		if (state == 1)
158			goto state1;
159		else if (state == 2)
160			goto state2;
161		else if (state == 3)
162			goto state3;
163		else
164			goto state4;
165	}
166	handler = &jmploc;
167#ifdef DEBUG
168	opentrace();
169	trputs("Shell args:  ");  trargs(argv);
170#endif
171	rootpid = getpid();
172	rootshell = 1;
173	init();
174	setstackmark(&smark);
175	procargs(argc, argv);
176	if (getpwd() == NULL && iflag)
177		out2str("sh: cannot determine working directory\n");
178	if (argv[0] && argv[0][0] == '-') {
179		state = 1;
180		read_profile("/etc/profile");
181state1:
182		state = 2;
183		if (privileged == 0)
184			read_profile(".profile");
185		else
186			read_profile("/etc/suid_profile");
187	}
188state2:
189	state = 3;
190	if (!privileged && iflag) {
191		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
192			state = 3;
193			read_profile(shinit);
194		}
195	}
196state3:
197	state = 4;
198	if (minusc) {
199		evalstring(minusc);
200	}
201	if (sflag || minusc == NULL) {
202state4:	/* XXX ??? - why isn't this before the "if" statement */
203		cmdloop(1);
204	}
205#if PROFILE
206	monitor(0);
207#endif
208	exitshell(exitstatus);
209	/*NOTREACHED*/
210	return 0;
211}
212
213
214/*
215 * Read and execute commands.  "Top" is nonzero for the top level command
216 * loop; it turns on prompting if the shell is interactive.
217 */
218
219void
220cmdloop(top)
221	int top;
222{
223	union node *n;
224	struct stackmark smark;
225	int inter;
226	int numeof = 0;
227
228	TRACE(("cmdloop(%d) called\n", top));
229	setstackmark(&smark);
230	for (;;) {
231		if (pendingsigs)
232			dotrap();
233		inter = 0;
234		if (iflag && top) {
235			inter++;
236			showjobs(1);
237			chkmail(0);
238			flushout(&output);
239		}
240		n = parsecmd(inter);
241		/* showtree(n); DEBUG */
242		if (n == NEOF) {
243			if (!top || numeof >= 50)
244				break;
245			if (!stoppedjobs()) {
246				if (!Iflag)
247					break;
248				out2str("\nUse \"exit\" to leave shell.\n");
249			}
250			numeof++;
251		} else if (n != NULL && nflag == 0) {
252			job_warning = (job_warning == 2) ? 1 : 0;
253			numeof = 0;
254			evaltree(n, 0);
255		}
256		popstackmark(&smark);
257		if (evalskip == SKIPFILE) {
258			evalskip = 0;
259			break;
260		}
261	}
262	popstackmark(&smark);		/* unnecessary */
263}
264
265
266
267/*
268 * Read /etc/profile or .profile.  Return on error.
269 */
270
271STATIC void
272read_profile(name)
273	char *name;
274	{
275	int fd;
276
277	INTOFF;
278	if ((fd = open(name, O_RDONLY)) >= 0)
279		setinputfd(fd, 1);
280	INTON;
281	if (fd < 0)
282		return;
283	cmdloop(0);
284	popfile();
285}
286
287
288
289/*
290 * Read a file containing shell functions.
291 */
292
293void
294readcmdfile(name)
295	char *name;
296{
297	int fd;
298
299	INTOFF;
300	if ((fd = open(name, O_RDONLY)) >= 0)
301		setinputfd(fd, 1);
302	else
303		error("Can't open %s", name);
304	INTON;
305	cmdloop(0);
306	popfile();
307}
308
309
310
311/*
312 * Take commands from a file.  To be compatable we should do a path
313 * search for the file, which is necessary to find sub-commands.
314 */
315
316
317STATIC char *
318find_dot_file(basename)
319	char *basename;
320{
321	static char localname[FILENAME_MAX+1];
322	char *fullname;
323	char *path = pathval();
324	struct stat statb;
325
326	/* don't try this for absolute or relative paths */
327	if( strchr(basename, '/'))
328		return basename;
329
330	while ((fullname = padvance(&path, basename)) != NULL) {
331		strcpy(localname, fullname);
332		stunalloc(fullname);
333		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
334			return localname;
335	}
336	return basename;
337}
338
339int
340dotcmd(argc, argv)
341	int argc;
342	char **argv;
343{
344	struct strlist *sp;
345	exitstatus = 0;
346
347	for (sp = cmdenviron; sp ; sp = sp->next)
348		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
349
350	if (argc >= 2) {		/* That's what SVR2 does */
351		char *fullname = find_dot_file(argv[1]);
352
353		setinputfile(fullname, 1);
354		commandname = fullname;
355		cmdloop(0);
356		popfile();
357	}
358	return exitstatus;
359}
360
361
362int
363exitcmd(argc, argv)
364	int argc;
365	char **argv;
366{
367	extern int oexitstatus;
368
369	if (stoppedjobs())
370		return 0;
371	if (argc > 1)
372		exitstatus = number(argv[1]);
373	else
374		exitstatus = oexitstatus;
375	exitshell(exitstatus);
376	/*NOTREACHED*/
377	return 0;
378}
379
380
381#ifdef notdef
382/*
383 * Should never be called.
384 */
385
386void
387exit(exitstatus) {
388	_exit(exitstatus);
389}
390#endif
391