main.c revision 8855 
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 *	$Id: main.c,v 1.2 1994/09/24 02:57:48 davidg Exp $
37 */
38
39#ifndef lint
40static char copyright[] =
41"@(#) Copyright (c) 1991, 1993\n\
42	The Regents of the University of California.  All rights reserved.\n";
43#endif /* not lint */
44
45#ifndef lint
46static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 5/31/93";
47#endif /* not lint */
48
49#include <signal.h>
50#include <fcntl.h>
51#include "shell.h"
52#include "main.h"
53#include "mail.h"
54#include "options.h"
55#include "output.h"
56#include "parser.h"
57#include "nodes.h"
58#include "eval.h"
59#include "jobs.h"
60#include "input.h"
61#include "trap.h"
62#include "var.h"
63#include "memalloc.h"
64#include "error.h"
65#include "init.h"
66#include "mystring.h"
67
68#define PROFILE 0
69
70int rootpid;
71int rootshell;
72STATIC union node *curcmd;
73STATIC union node *prevcmd;
74extern int errno;
75#if PROFILE
76short profile_buf[16384];
77extern int etext();
78#endif
79
80#ifdef __STDC__
81STATIC void read_profile(char *);
82char *getenv(char *);
83#else
84STATIC void read_profile();
85char *getenv();
86#endif
87
88
89/*
90 * Main routine.  We initialize things, parse the arguments, execute
91 * profiles if we're a login shell, and then call cmdloop to execute
92 * commands.  The setjmp call sets up the location to jump to when an
93 * exception occurs.  When an exception occurs the variable "state"
94 * is used to figure out how far we had gotten.
95 */
96
97main(argc, argv)  char **argv; {
98	struct jmploc jmploc;
99	struct stackmark smark;
100	volatile int state;
101	char *shinit;
102
103#if PROFILE
104	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
105#endif
106	state = 0;
107	if (setjmp(jmploc.loc)) {
108		/*
109		 * When a shell procedure is executed, we raise the
110		 * exception EXSHELLPROC to clean up before executing
111		 * the shell procedure.
112		 */
113		if (exception == EXSHELLPROC) {
114			rootpid = getpid();
115			rootshell = 1;
116			minusc = NULL;
117			state = 3;
118		} else if (state == 0 || iflag == 0 || ! rootshell)
119			exitshell(2);
120		reset();
121		if (exception == EXINT
122#if ATTY
123		 && (! attyset() || equal(termval(), "emacs"))
124#endif
125		 ) {
126			out2c('\n');
127			flushout(&errout);
128		}
129		popstackmark(&smark);
130		FORCEINTON;				/* enable interrupts */
131		if (state == 1)
132			goto state1;
133		else if (state == 2)
134			goto state2;
135		else if (state == 3)
136			goto state3;
137		else
138			goto state4;
139	}
140	handler = &jmploc;
141#ifdef DEBUG
142	opentrace();
143	trputs("Shell args:  ");  trargs(argv);
144#endif
145	rootpid = getpid();
146	rootshell = 1;
147	init();
148	setstackmark(&smark);
149	procargs(argc, argv);
150	if (argv[0] && argv[0][0] == '-') {
151		state = 1;
152		read_profile("/etc/profile");
153state1:
154		state = 2;
155		read_profile(".profile");
156	}
157state2:
158	state = 3;
159	if ((shinit = lookupvar("ENV")) != NULL &&
160	     *shinit != '\0') {
161		state = 3;
162		read_profile(shinit);
163	}
164state3:
165	state = 4;
166	if (minusc) {
167		evalstring(minusc);
168	}
169	if (sflag || minusc == NULL) {
170state4:	/* XXX ??? - why isn't this before the "if" statement */
171		cmdloop(1);
172	}
173#if PROFILE
174	monitor(0);
175#endif
176	exitshell(exitstatus);
177}
178
179
180/*
181 * Read and execute commands.  "Top" is nonzero for the top level command
182 * loop; it turns on prompting if the shell is interactive.
183 */
184
185void
186cmdloop(top) {
187	union node *n;
188	struct stackmark smark;
189	int inter;
190	int numeof = 0;
191
192	TRACE(("cmdloop(%d) called\n", top));
193	setstackmark(&smark);
194	for (;;) {
195		if (pendingsigs)
196			dotrap();
197		inter = 0;
198		if (iflag && top) {
199			inter++;
200			showjobs(1);
201			chkmail(0);
202			flushout(&output);
203		}
204		n = parsecmd(inter);
205		/* showtree(n); DEBUG */
206		if (n == NEOF) {
207			if (!top || numeof >= 50)
208				break;
209			if (!stoppedjobs()) {
210				if (!Iflag)
211					break;
212				out2str("\nUse \"exit\" to leave shell.\n");
213			}
214			numeof++;
215		} else if (n != NULL && nflag == 0) {
216			job_warning = (job_warning == 2) ? 1 : 0;
217			numeof = 0;
218			evaltree(n, 0);
219		}
220		popstackmark(&smark);
221	}
222	popstackmark(&smark);		/* unnecessary */
223}
224
225
226
227/*
228 * Read /etc/profile or .profile.  Return on error.
229 */
230
231STATIC void
232read_profile(name)
233	char *name;
234	{
235	int fd;
236
237	INTOFF;
238	if ((fd = open(name, O_RDONLY)) >= 0)
239		setinputfd(fd, 1);
240	INTON;
241	if (fd < 0)
242		return;
243	cmdloop(0);
244	popfile();
245}
246
247
248
249/*
250 * Read a file containing shell functions.
251 */
252
253void
254readcmdfile(name)
255	char *name;
256	{
257	int fd;
258
259	INTOFF;
260	if ((fd = open(name, O_RDONLY)) >= 0)
261		setinputfd(fd, 1);
262	else
263		error("Can't open %s", name);
264	INTON;
265	cmdloop(0);
266	popfile();
267}
268
269
270
271/*
272 * Take commands from a file.  To be compatable we should do a path
273 * search for the file, but a path search doesn't make any sense.
274 */
275
276dotcmd(argc, argv)  char **argv; {
277	exitstatus = 0;
278	if (argc >= 2) {		/* That's what SVR2 does */
279		setinputfile(argv[1], 1);
280		commandname = argv[1];
281		cmdloop(0);
282		popfile();
283	}
284	return exitstatus;
285}
286
287
288exitcmd(argc, argv)  char **argv; {
289	if (stoppedjobs())
290		return;
291	if (argc > 1)
292		exitstatus = number(argv[1]);
293	exitshell(exitstatus);
294}
295
296
297#ifdef notdef
298/*
299 * Should never be called.
300 */
301
302void
303exit(exitstatus) {
304	_exit(exitstatus);
305}
306#endif
307