xref: /netbsd-src/bin/sh/main.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: main.c,v 1.26 1997/07/04 21:02:07 christos 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 #include <sys/cdefs.h>
40 #ifndef lint
41 __COPYRIGHT("@(#) 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	8.7 (Berkeley) 7/19/95";
48 #else
49 __RCSID("$NetBSD: main.c,v 1.26 1997/07/04 21:02:07 christos 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 
59 
60 #include "shell.h"
61 #include "main.h"
62 #include "mail.h"
63 #include "options.h"
64 #include "output.h"
65 #include "parser.h"
66 #include "nodes.h"
67 #include "expand.h"
68 #include "eval.h"
69 #include "jobs.h"
70 #include "input.h"
71 #include "trap.h"
72 #include "var.h"
73 #include "show.h"
74 #include "memalloc.h"
75 #include "error.h"
76 #include "init.h"
77 #include "mystring.h"
78 #include "exec.h"
79 #include "cd.h"
80 
81 #define PROFILE 0
82 
83 int rootpid;
84 int rootshell;
85 STATIC union node *curcmd;
86 STATIC union node *prevcmd;
87 extern int errno;
88 #if PROFILE
89 short profile_buf[16384];
90 extern int etext();
91 #endif
92 
93 STATIC void read_profile __P((char *));
94 STATIC char *find_dot_file __P((char *));
95 int main __P((int, char **));
96 
97 /*
98  * Main routine.  We initialize things, parse the arguments, execute
99  * profiles if we're a login shell, and then call cmdloop to execute
100  * commands.  The setjmp call sets up the location to jump to when an
101  * exception occurs.  When an exception occurs the variable "state"
102  * is used to figure out how far we had gotten.
103  */
104 
105 int
106 main(argc, argv)
107 	int argc;
108 	char **argv;
109 {
110 	struct jmploc jmploc;
111 	struct stackmark smark;
112 	volatile int state;
113 	char *shinit;
114 
115 #if PROFILE
116 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
117 #endif
118 	state = 0;
119 	if (setjmp(jmploc.loc)) {
120 		/*
121 		 * When a shell procedure is executed, we raise the
122 		 * exception EXSHELLPROC to clean up before executing
123 		 * the shell procedure.
124 		 */
125 		switch (exception) {
126 		case EXSHELLPROC:
127 			rootpid = getpid();
128 			rootshell = 1;
129 			minusc = NULL;
130 			state = 3;
131 			break;
132 
133 		case EXEXEC:
134 			exitstatus = exerrno;
135 			break;
136 
137 		case EXERROR:
138 			exitstatus = 2;
139 			break;
140 
141 		default:
142 			break;
143 		}
144 
145 		if (exception != EXSHELLPROC) {
146 		    if (state == 0 || iflag == 0 || ! rootshell)
147 			    exitshell(exitstatus);
148 		}
149 		reset();
150 		if (exception == EXINT
151 #if ATTY
152 		 && (! attyset() || equal(termval(), "emacs"))
153 #endif
154 		 ) {
155 			out2c('\n');
156 			flushout(&errout);
157 		}
158 		popstackmark(&smark);
159 		FORCEINTON;				/* enable interrupts */
160 		if (state == 1)
161 			goto state1;
162 		else if (state == 2)
163 			goto state2;
164 		else if (state == 3)
165 			goto state3;
166 		else
167 			goto state4;
168 	}
169 	handler = &jmploc;
170 #ifdef DEBUG
171 	opentrace();
172 	trputs("Shell args:  ");  trargs(argv);
173 #endif
174 	rootpid = getpid();
175 	rootshell = 1;
176 	init();
177 	setstackmark(&smark);
178 	procargs(argc, argv);
179 	if (argv[0] && argv[0][0] == '-') {
180 		state = 1;
181 		read_profile("/etc/profile");
182 state1:
183 		state = 2;
184 		read_profile(".profile");
185 	}
186 state2:
187 	state = 3;
188 	if (getuid() == geteuid() && getgid() == getegid()) {
189 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
190 			state = 3;
191 			read_profile(shinit);
192 		}
193 	}
194 state3:
195 	state = 4;
196 	if (minusc) {
197 		evalstring(minusc);
198 	}
199 	if (sflag || minusc == NULL) {
200 state4:	/* XXX ??? - why isn't this before the "if" statement */
201 		cmdloop(1);
202 	}
203 #if PROFILE
204 	monitor(0);
205 #endif
206 	exitshell(exitstatus);
207 	/*NOTREACHED*/
208 	return 0;
209 }
210 
211 
212 /*
213  * Read and execute commands.  "Top" is nonzero for the top level command
214  * loop; it turns on prompting if the shell is interactive.
215  */
216 
217 void
218 cmdloop(top)
219 	int top;
220 {
221 	union node *n;
222 	struct stackmark smark;
223 	int inter;
224 	int numeof = 0;
225 
226 	TRACE(("cmdloop(%d) called\n", top));
227 	setstackmark(&smark);
228 	for (;;) {
229 		if (pendingsigs)
230 			dotrap();
231 		inter = 0;
232 		if (iflag && top) {
233 			inter++;
234 			showjobs(1);
235 			chkmail(0);
236 			flushout(&output);
237 		}
238 		n = parsecmd(inter);
239 		/* showtree(n); DEBUG */
240 		if (n == NEOF) {
241 			if (!top || numeof >= 50)
242 				break;
243 			if (!stoppedjobs()) {
244 				if (!Iflag)
245 					break;
246 				out2str("\nUse \"exit\" to leave shell.\n");
247 			}
248 			numeof++;
249 		} else if (n != NULL && nflag == 0) {
250 			job_warning = (job_warning == 2) ? 1 : 0;
251 			numeof = 0;
252 			evaltree(n, 0);
253 		}
254 		popstackmark(&smark);
255 		if (evalskip == SKIPFILE) {
256 			evalskip = 0;
257 			break;
258 		}
259 	}
260 	popstackmark(&smark);		/* unnecessary */
261 }
262 
263 
264 
265 /*
266  * Read /etc/profile or .profile.  Return on error.
267  */
268 
269 STATIC void
270 read_profile(name)
271 	char *name;
272 	{
273 	int fd;
274 
275 	INTOFF;
276 	if ((fd = open(name, O_RDONLY)) >= 0)
277 		setinputfd(fd, 1);
278 	INTON;
279 	if (fd < 0)
280 		return;
281 	cmdloop(0);
282 	popfile();
283 }
284 
285 
286 
287 /*
288  * Read a file containing shell functions.
289  */
290 
291 void
292 readcmdfile(name)
293 	char *name;
294 {
295 	int fd;
296 
297 	INTOFF;
298 	if ((fd = open(name, O_RDONLY)) >= 0)
299 		setinputfd(fd, 1);
300 	else
301 		error("Can't open %s", name);
302 	INTON;
303 	cmdloop(0);
304 	popfile();
305 }
306 
307 
308 
309 /*
310  * Take commands from a file.  To be compatable we should do a path
311  * search for the file, which is necessary to find sub-commands.
312  */
313 
314 
315 STATIC char *
316 find_dot_file(basename)
317 	char *basename;
318 {
319 	static char localname[FILENAME_MAX+1];
320 	char *fullname;
321 	char *path = pathval();
322 	struct stat statb;
323 
324 	/* don't try this for absolute or relative paths */
325 	if( strchr(basename, '/'))
326 		return basename;
327 
328 	while ((fullname = padvance(&path, basename)) != NULL) {
329 		strcpy(localname, fullname);
330 		stunalloc(fullname);
331 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
332 			return localname;
333 	}
334 	return basename;
335 }
336 
337 int
338 dotcmd(argc, argv)
339 	int argc;
340 	char **argv;
341 {
342 	struct strlist *sp;
343 	exitstatus = 0;
344 
345 	for (sp = cmdenviron; sp ; sp = sp->next)
346 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
347 
348 	if (argc >= 2) {		/* That's what SVR2 does */
349 		char *fullname = find_dot_file(argv[1]);
350 
351 		setinputfile(fullname, 1);
352 		commandname = fullname;
353 		cmdloop(0);
354 		popfile();
355 	}
356 	return exitstatus;
357 }
358 
359 
360 int
361 exitcmd(argc, argv)
362 	int argc;
363 	char **argv;
364 {
365 	extern int oexitstatus;
366 
367 	if (stoppedjobs())
368 		return 0;
369 	if (argc > 1)
370 		exitstatus = number(argv[1]);
371 	else
372 		exitstatus = oexitstatus;
373 	exitshell(exitstatus);
374 	/*NOTREACHED*/
375 	return 0;
376 }
377 
378 
379 #ifdef notdef
380 /*
381  * Should never be called.
382  */
383 
384 void
385 exit(exitstatus) {
386 	_exit(exitstatus);
387 }
388 #endif
389