xref: /netbsd-src/bin/sh/main.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*	$NetBSD: main.c,v 1.17 1995/03/21 09:09:26 cgd Exp $	*/
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #ifndef lint
40 static 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
46 #if 0
47 static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 5/31/93";
48 #else
49 static char rcsid[] = "$NetBSD: main.c,v 1.17 1995/03/21 09:09:26 cgd Exp $";
50 #endif
51 #endif /* not lint */
52 
53 #include <stdio.h>
54 #include <signal.h>
55 #include <sys/stat.h>
56 #include <unistd.h>
57 #include <fcntl.h>
58 #include "shell.h"
59 #include "main.h"
60 #include "mail.h"
61 #include "options.h"
62 #include "output.h"
63 #include "parser.h"
64 #include "nodes.h"
65 #include "eval.h"
66 #include "jobs.h"
67 #include "input.h"
68 #include "trap.h"
69 #include "var.h"
70 #include "memalloc.h"
71 #include "error.h"
72 #include "init.h"
73 #include "mystring.h"
74 #include "exec.h"
75 #include "extern.h"
76 
77 #define PROFILE 0
78 
79 int rootpid;
80 int rootshell;
81 STATIC union node *curcmd;
82 STATIC union node *prevcmd;
83 extern int errno;
84 #if PROFILE
85 short profile_buf[16384];
86 extern int etext();
87 #endif
88 
89 #ifdef __STDC__
90 STATIC void read_profile(char *);
91 char *getenv(char *);
92 #else
93 STATIC void read_profile();
94 char *getenv();
95 #endif
96 
97 
98 /*
99  * Main routine.  We initialize things, parse the arguments, execute
100  * profiles if we're a login shell, and then call cmdloop to execute
101  * commands.  The setjmp call sets up the location to jump to when an
102  * exception occurs.  When an exception occurs the variable "state"
103  * is used to figure out how far we had gotten.
104  */
105 
106 int
107 main(argc, argv)
108 	int argc;
109 	char **argv;
110 {
111 	struct jmploc jmploc;
112 	struct stackmark smark;
113 	volatile int state;
114 	char *shinit;
115 
116 #if PROFILE
117 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
118 #endif
119 	state = 0;
120 	if (setjmp(jmploc.loc)) {
121 		/*
122 		 * When a shell procedure is executed, we raise the
123 		 * exception EXSHELLPROC to clean up before executing
124 		 * the shell procedure.
125 		 */
126 		if (exception == EXSHELLPROC) {
127 			rootpid = getpid();
128 			rootshell = 1;
129 			minusc = NULL;
130 			state = 3;
131 		} else if (state == 0 || iflag == 0 || ! rootshell)
132 			exitshell(2);
133 		reset();
134 		if (exception == EXINT
135 #if ATTY
136 		 && (! attyset() || equal(termval(), "emacs"))
137 #endif
138 		 ) {
139 			out2c('\n');
140 			flushout(&errout);
141 		}
142 		popstackmark(&smark);
143 		FORCEINTON;				/* enable interrupts */
144 		if (state == 1)
145 			goto state1;
146 		else if (state == 2)
147 			goto state2;
148 		else if (state == 3)
149 			goto state3;
150 		else
151 			goto state4;
152 	}
153 	handler = &jmploc;
154 #ifdef DEBUG
155 	opentrace();
156 	trputs("Shell args:  ");  trargs(argv);
157 #endif
158 	rootpid = getpid();
159 	rootshell = 1;
160 	init();
161 	setstackmark(&smark);
162 	procargs(argc, argv);
163 	if (argv[0] && argv[0][0] == '-') {
164 		state = 1;
165 		read_profile("/etc/profile");
166 state1:
167 		state = 2;
168 		read_profile(".profile");
169 	}
170 state2:
171 	state = 3;
172 	if (getuid() == geteuid() && getgid() == getegid()) {
173 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
174 			state = 3;
175 			read_profile(shinit);
176 		}
177 	}
178 state3:
179 	state = 4;
180 	if (minusc) {
181 		evalstring(minusc);
182 	}
183 	if (sflag || minusc == NULL) {
184 state4:	/* XXX ??? - why isn't this before the "if" statement */
185 		cmdloop(1);
186 	}
187 #if PROFILE
188 	monitor(0);
189 #endif
190 	exitshell(exitstatus);
191 }
192 
193 
194 /*
195  * Read and execute commands.  "Top" is nonzero for the top level command
196  * loop; it turns on prompting if the shell is interactive.
197  */
198 
199 void
200 cmdloop(top)
201 	int top;
202 {
203 	union node *n;
204 	struct stackmark smark;
205 	int inter;
206 	int numeof = 0;
207 
208 	TRACE(("cmdloop(%d) called\n", top));
209 	setstackmark(&smark);
210 	for (;;) {
211 		if (pendingsigs)
212 			dotrap();
213 		inter = 0;
214 		if (iflag && top) {
215 			inter++;
216 			showjobs(1);
217 			chkmail(0);
218 			flushout(&output);
219 		}
220 		n = parsecmd(inter);
221 		/* showtree(n); DEBUG */
222 		if (n == NEOF) {
223 			if (!top || numeof >= 50)
224 				break;
225 			if (!stoppedjobs()) {
226 				if (!Iflag)
227 					break;
228 				out2str("\nUse \"exit\" to leave shell.\n");
229 			}
230 			numeof++;
231 		} else if (n != NULL && nflag == 0) {
232 			job_warning = (job_warning == 2) ? 1 : 0;
233 			numeof = 0;
234 			evaltree(n, 0);
235 		}
236 		popstackmark(&smark);
237 	}
238 	popstackmark(&smark);		/* unnecessary */
239 }
240 
241 
242 
243 /*
244  * Read /etc/profile or .profile.  Return on error.
245  */
246 
247 STATIC void
248 read_profile(name)
249 	char *name;
250 	{
251 	int fd;
252 
253 	INTOFF;
254 	if ((fd = open(name, O_RDONLY)) >= 0)
255 		setinputfd(fd, 1);
256 	INTON;
257 	if (fd < 0)
258 		return;
259 	cmdloop(0);
260 	popfile();
261 }
262 
263 
264 
265 /*
266  * Read a file containing shell functions.
267  */
268 
269 void
270 readcmdfile(name)
271 	char *name;
272 {
273 	int fd;
274 
275 	INTOFF;
276 	if ((fd = open(name, O_RDONLY)) >= 0)
277 		setinputfd(fd, 1);
278 	else
279 		error("Can't open %s", name);
280 	INTON;
281 	cmdloop(0);
282 	popfile();
283 }
284 
285 
286 
287 /*
288  * Take commands from a file.  To be compatable we should do a path
289  * search for the file, which is necessary to find sub-commands.
290  */
291 
292 
293 static char *
294 find_dot_file(basename) char *basename; {
295 	static char localname[FILENAME_MAX+1];
296 	char *fullname;
297 	char *path = pathval();
298 	struct stat statb;
299 
300 	/* don't try this for absolute or relative paths */
301 	if( strchr(basename, '/'))
302 		return basename;
303 
304 	while ((fullname = padvance(&path, basename)) != NULL) {
305 		strcpy(localname, fullname);
306 		stunalloc(fullname);
307 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
308 			return localname;
309 	}
310 	return basename;
311 }
312 
313 int
314 dotcmd(argc, argv)
315 	int argc;
316 	char **argv;
317 {
318 	exitstatus = 0;
319 	if (argc >= 2) {		/* That's what SVR2 does */
320 		char *fullname = find_dot_file(argv[1]);
321 		setinputfile(fullname, 1);
322 		commandname = fullname;
323 		cmdloop(0);
324 		popfile();
325 	}
326 	return exitstatus;
327 }
328 
329 
330 int
331 exitcmd(argc, argv)
332 	int argc;
333 	char **argv;
334 {
335 	if (stoppedjobs())
336 		return;
337 	if (argc > 1)
338 		exitstatus = number(argv[1]);
339 	exitshell(exitstatus);
340 }
341 
342 
343 #ifdef notdef
344 /*
345  * Should never be called.
346  */
347 
348 void
349 exit(exitstatus) {
350 	_exit(exitstatus);
351 }
352 #endif
353