main.c revision 1556 
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 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
44static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 5/31/93";
45#endif /* not lint */
46
47#include <signal.h>
48#include <fcntl.h>
49#include "shell.h"
50#include "main.h"
51#include "mail.h"
52#include "options.h"
53#include "output.h"
54#include "parser.h"
55#include "nodes.h"
56#include "eval.h"
57#include "jobs.h"
58#include "input.h"
59#include "trap.h"
60#include "var.h"
61#include "memalloc.h"
62#include "error.h"
63#include "init.h"
64#include "mystring.h"
65
66#define PROFILE 0
67
68int rootpid;
69int rootshell;
70STATIC union node *curcmd;
71STATIC union node *prevcmd;
72extern int errno;
73#if PROFILE
74short profile_buf[16384];
75extern int etext();
76#endif
77
78#ifdef __STDC__
79STATIC void read_profile(char *);
80char *getenv(char *);
81#else
82STATIC void read_profile();
83char *getenv();
84#endif
85
86
87/*
88 * Main routine.  We initialize things, parse the arguments, execute
89 * profiles if we're a login shell, and then call cmdloop to execute
90 * commands.  The setjmp call sets up the location to jump to when an
91 * exception occurs.  When an exception occurs the variable "state"
92 * is used to figure out how far we had gotten.
93 */
94
95main(argc, argv)  char **argv; {
96	struct jmploc jmploc;
97	struct stackmark smark;
98	volatile int state;
99	char *shinit;
100
101#if PROFILE
102	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
103#endif
104	state = 0;
105	if (setjmp(jmploc.loc)) {
106		/*
107		 * When a shell procedure is executed, we raise the
108		 * exception EXSHELLPROC to clean up before executing
109		 * the shell procedure.
110		 */
111		if (exception == EXSHELLPROC) {
112			rootpid = getpid();
113			rootshell = 1;
114			minusc = NULL;
115			state = 3;
116		} else if (state == 0 || iflag == 0 || ! rootshell)
117			exitshell(2);
118		reset();
119		if (exception == EXINT
120#if ATTY
121		 && (! attyset() || equal(termval(), "emacs"))
122#endif
123		 ) {
124			out2c('\n');
125			flushout(&errout);
126		}
127		popstackmark(&smark);
128		FORCEINTON;				/* enable interrupts */
129		if (state == 1)
130			goto state1;
131		else if (state == 2)
132			goto state2;
133		else if (state == 3)
134			goto state3;
135		else
136			goto state4;
137	}
138	handler = &jmploc;
139#ifdef DEBUG
140	opentrace();
141	trputs("Shell args:  ");  trargs(argv);
142#endif
143	rootpid = getpid();
144	rootshell = 1;
145	init();
146	setstackmark(&smark);
147	procargs(argc, argv);
148	if (argv[0] && argv[0][0] == '-') {
149		state = 1;
150		read_profile("/etc/profile");
151state1:
152		state = 2;
153		read_profile(".profile");
154	}
155state2:
156	state = 3;
157	if ((shinit = lookupvar("ENV")) != NULL &&
158	     *shinit != '\0') {
159		state = 3;
160		read_profile(shinit);
161	}
162state3:
163	state = 4;
164	if (minusc) {
165		evalstring(minusc);
166	}
167	if (sflag || minusc == NULL) {
168state4:	/* XXX ??? - why isn't this before the "if" statement */
169		cmdloop(1);
170	}
171#if PROFILE
172	monitor(0);
173#endif
174	exitshell(exitstatus);
175}
176
177
178/*
179 * Read and execute commands.  "Top" is nonzero for the top level command
180 * loop; it turns on prompting if the shell is interactive.
181 */
182
183void
184cmdloop(top) {
185	union node *n;
186	struct stackmark smark;
187	int inter;
188	int numeof = 0;
189
190	TRACE(("cmdloop(%d) called\n", top));
191	setstackmark(&smark);
192	for (;;) {
193		if (pendingsigs)
194			dotrap();
195		inter = 0;
196		if (iflag && top) {
197			inter++;
198			showjobs(1);
199			chkmail(0);
200			flushout(&output);
201		}
202		n = parsecmd(inter);
203		/* showtree(n); DEBUG */
204		if (n == NEOF) {
205			if (!top || numeof >= 50)
206				break;
207			if (!stoppedjobs()) {
208				if (!Iflag)
209					break;
210				out2str("\nUse \"exit\" to leave shell.\n");
211			}
212			numeof++;
213		} else if (n != NULL && nflag == 0) {
214			job_warning = (job_warning == 2) ? 1 : 0;
215			numeof = 0;
216			evaltree(n, 0);
217		}
218		popstackmark(&smark);
219	}
220	popstackmark(&smark);		/* unnecessary */
221}
222
223
224
225/*
226 * Read /etc/profile or .profile.  Return on error.
227 */
228
229STATIC void
230read_profile(name)
231	char *name;
232	{
233	int fd;
234
235	INTOFF;
236	if ((fd = open(name, O_RDONLY)) >= 0)
237		setinputfd(fd, 1);
238	INTON;
239	if (fd < 0)
240		return;
241	cmdloop(0);
242	popfile();
243}
244
245
246
247/*
248 * Read a file containing shell functions.
249 */
250
251void
252readcmdfile(name)
253	char *name;
254	{
255	int fd;
256
257	INTOFF;
258	if ((fd = open(name, O_RDONLY)) >= 0)
259		setinputfd(fd, 1);
260	else
261		error("Can't open %s", name);
262	INTON;
263	cmdloop(0);
264	popfile();
265}
266
267
268
269/*
270 * Take commands from a file.  To be compatable we should do a path
271 * search for the file, but a path search doesn't make any sense.
272 */
273
274dotcmd(argc, argv)  char **argv; {
275	exitstatus = 0;
276	if (argc >= 2) {		/* That's what SVR2 does */
277		setinputfile(argv[1], 1);
278		commandname = argv[1];
279		cmdloop(0);
280		popfile();
281	}
282	return exitstatus;
283}
284
285
286exitcmd(argc, argv)  char **argv; {
287	if (stoppedjobs())
288		return;
289	if (argc > 1)
290		exitstatus = number(argv[1]);
291	exitshell(exitstatus);
292}
293
294
295#ifdef notdef
296/*
297 * Should never be called.
298 */
299
300void
301exit(exitstatus) {
302	_exit(exitstatus);
303}
304#endif
305