xref: /netbsd-src/bin/sh/main.c (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
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
38 static 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
44 /*static char sccsid[] = "from: @(#)main.c	8.1 (Berkeley) 5/31/93";*/
45 static char *rcsid = "$Id: main.c,v 1.16 1994/12/05 19:07:43 cgd Exp $";
46 #endif /* not lint */
47 
48 #include <stdio.h>
49 #include <signal.h>
50 #include <sys/stat.h>
51 #include <unistd.h>
52 #include <fcntl.h>
53 #include "shell.h"
54 #include "main.h"
55 #include "mail.h"
56 #include "options.h"
57 #include "output.h"
58 #include "parser.h"
59 #include "nodes.h"
60 #include "eval.h"
61 #include "jobs.h"
62 #include "input.h"
63 #include "trap.h"
64 #include "var.h"
65 #include "memalloc.h"
66 #include "error.h"
67 #include "init.h"
68 #include "mystring.h"
69 #include "exec.h"
70 #include "extern.h"
71 
72 #define PROFILE 0
73 
74 int rootpid;
75 int rootshell;
76 STATIC union node *curcmd;
77 STATIC union node *prevcmd;
78 extern int errno;
79 #if PROFILE
80 short profile_buf[16384];
81 extern int etext();
82 #endif
83 
84 #ifdef __STDC__
85 STATIC void read_profile(char *);
86 char *getenv(char *);
87 #else
88 STATIC void read_profile();
89 char *getenv();
90 #endif
91 
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 
101 int
102 main(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 	state = 0;
115 	if (setjmp(jmploc.loc)) {
116 		/*
117 		 * When a shell procedure is executed, we raise the
118 		 * exception EXSHELLPROC to clean up before executing
119 		 * the shell procedure.
120 		 */
121 		if (exception == EXSHELLPROC) {
122 			rootpid = getpid();
123 			rootshell = 1;
124 			minusc = NULL;
125 			state = 3;
126 		} else if (state == 0 || iflag == 0 || ! rootshell)
127 			exitshell(2);
128 		reset();
129 		if (exception == EXINT
130 #if ATTY
131 		 && (! attyset() || equal(termval(), "emacs"))
132 #endif
133 		 ) {
134 			out2c('\n');
135 			flushout(&errout);
136 		}
137 		popstackmark(&smark);
138 		FORCEINTON;				/* enable interrupts */
139 		if (state == 1)
140 			goto state1;
141 		else if (state == 2)
142 			goto state2;
143 		else if (state == 3)
144 			goto state3;
145 		else
146 			goto state4;
147 	}
148 	handler = &jmploc;
149 #ifdef DEBUG
150 	opentrace();
151 	trputs("Shell args:  ");  trargs(argv);
152 #endif
153 	rootpid = getpid();
154 	rootshell = 1;
155 	init();
156 	setstackmark(&smark);
157 	procargs(argc, argv);
158 	if (argv[0] && argv[0][0] == '-') {
159 		state = 1;
160 		read_profile("/etc/profile");
161 state1:
162 		state = 2;
163 		read_profile(".profile");
164 	}
165 state2:
166 	state = 3;
167 	if (getuid() == geteuid() && getgid() == getegid()) {
168 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
169 			state = 3;
170 			read_profile(shinit);
171 		}
172 	}
173 state3:
174 	state = 4;
175 	if (minusc) {
176 		evalstring(minusc);
177 	}
178 	if (sflag || minusc == NULL) {
179 state4:	/* XXX ??? - why isn't this before the "if" statement */
180 		cmdloop(1);
181 	}
182 #if PROFILE
183 	monitor(0);
184 #endif
185 	exitshell(exitstatus);
186 }
187 
188 
189 /*
190  * Read and execute commands.  "Top" is nonzero for the top level command
191  * loop; it turns on prompting if the shell is interactive.
192  */
193 
194 void
195 cmdloop(top)
196 	int top;
197 {
198 	union node *n;
199 	struct stackmark smark;
200 	int inter;
201 	int numeof = 0;
202 
203 	TRACE(("cmdloop(%d) called\n", top));
204 	setstackmark(&smark);
205 	for (;;) {
206 		if (pendingsigs)
207 			dotrap();
208 		inter = 0;
209 		if (iflag && top) {
210 			inter++;
211 			showjobs(1);
212 			chkmail(0);
213 			flushout(&output);
214 		}
215 		n = parsecmd(inter);
216 		/* showtree(n); DEBUG */
217 		if (n == NEOF) {
218 			if (!top || numeof >= 50)
219 				break;
220 			if (!stoppedjobs()) {
221 				if (!Iflag)
222 					break;
223 				out2str("\nUse \"exit\" to leave shell.\n");
224 			}
225 			numeof++;
226 		} else if (n != NULL && nflag == 0) {
227 			job_warning = (job_warning == 2) ? 1 : 0;
228 			numeof = 0;
229 			evaltree(n, 0);
230 		}
231 		popstackmark(&smark);
232 	}
233 	popstackmark(&smark);		/* unnecessary */
234 }
235 
236 
237 
238 /*
239  * Read /etc/profile or .profile.  Return on error.
240  */
241 
242 STATIC void
243 read_profile(name)
244 	char *name;
245 	{
246 	int fd;
247 
248 	INTOFF;
249 	if ((fd = open(name, O_RDONLY)) >= 0)
250 		setinputfd(fd, 1);
251 	INTON;
252 	if (fd < 0)
253 		return;
254 	cmdloop(0);
255 	popfile();
256 }
257 
258 
259 
260 /*
261  * Read a file containing shell functions.
262  */
263 
264 void
265 readcmdfile(name)
266 	char *name;
267 {
268 	int fd;
269 
270 	INTOFF;
271 	if ((fd = open(name, O_RDONLY)) >= 0)
272 		setinputfd(fd, 1);
273 	else
274 		error("Can't open %s", name);
275 	INTON;
276 	cmdloop(0);
277 	popfile();
278 }
279 
280 
281 
282 /*
283  * Take commands from a file.  To be compatable we should do a path
284  * search for the file, which is necessary to find sub-commands.
285  */
286 
287 
288 static char *
289 find_dot_file(basename) char *basename; {
290 	static char localname[FILENAME_MAX+1];
291 	char *fullname;
292 	char *path = pathval();
293 	struct stat statb;
294 
295 	/* don't try this for absolute or relative paths */
296 	if( strchr(basename, '/'))
297 		return basename;
298 
299 	while ((fullname = padvance(&path, basename)) != NULL) {
300 		strcpy(localname, fullname);
301 		stunalloc(fullname);
302 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
303 			return localname;
304 	}
305 	return basename;
306 }
307 
308 int
309 dotcmd(argc, argv)
310 	int argc;
311 	char **argv;
312 {
313 	exitstatus = 0;
314 	if (argc >= 2) {		/* That's what SVR2 does */
315 		char *fullname = find_dot_file(argv[1]);
316 		setinputfile(fullname, 1);
317 		commandname = fullname;
318 		cmdloop(0);
319 		popfile();
320 	}
321 	return exitstatus;
322 }
323 
324 
325 int
326 exitcmd(argc, argv)
327 	int argc;
328 	char **argv;
329 {
330 	if (stoppedjobs())
331 		return;
332 	if (argc > 1)
333 		exitstatus = number(argv[1]);
334 	exitshell(exitstatus);
335 }
336 
337 
338 #ifdef notdef
339 /*
340  * Should never be called.
341  */
342 
343 void
344 exit(exitstatus) {
345 	_exit(exitstatus);
346 }
347 #endif
348