xref: /netbsd-src/bin/sh/main.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: main.c,v 1.38 2000/05/22 10:18:47 elric 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 1.38 2000/05/22 10:18:47 elric Exp $");
50 #endif
51 #endif /* not lint */
52 
53 #include <errno.h>
54 #include <stdio.h>
55 #include <signal.h>
56 #include <sys/stat.h>
57 #include <unistd.h>
58 #include <fcntl.h>
59 
60 
61 #include "shell.h"
62 #include "main.h"
63 #include "mail.h"
64 #include "options.h"
65 #include "output.h"
66 #include "parser.h"
67 #include "nodes.h"
68 #include "expand.h"
69 #include "eval.h"
70 #include "jobs.h"
71 #include "input.h"
72 #include "trap.h"
73 #include "var.h"
74 #include "show.h"
75 #include "memalloc.h"
76 #include "error.h"
77 #include "init.h"
78 #include "mystring.h"
79 #include "exec.h"
80 #include "cd.h"
81 
82 #define PROFILE 0
83 
84 int rootpid;
85 int rootshell;
86 STATIC union node *curcmd;
87 STATIC union node *prevcmd;
88 #if PROFILE
89 short profile_buf[16384];
90 extern int etext();
91 #endif
92 
93 STATIC void read_profile __P((const 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 (sflag == 0 || minusc) {
197 		static int sigs[] =  {
198 		    SIGINT, SIGQUIT, SIGHUP,
199 #ifdef SIGTSTP
200 		    SIGTSTP,
201 #endif
202 		    SIGPIPE
203 		};
204 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
205 		int i;
206 
207 		for (i = 0; i < SIGSSIZE; i++)
208 		    setsignal(sigs[i]);
209 	}
210 
211 	if (minusc)
212 		evalstring(minusc, 0);
213 
214 	if (sflag || minusc == NULL) {
215 state4:	/* XXX ??? - why isn't this before the "if" statement */
216 		cmdloop(1);
217 	}
218 #if PROFILE
219 	monitor(0);
220 #endif
221 	exitshell(exitstatus);
222 	/* NOTREACHED */
223 }
224 
225 
226 /*
227  * Read and execute commands.  "Top" is nonzero for the top level command
228  * loop; it turns on prompting if the shell is interactive.
229  */
230 
231 void
232 cmdloop(top)
233 	int top;
234 {
235 	union node *n;
236 	struct stackmark smark;
237 	int inter;
238 	int numeof = 0;
239 
240 	TRACE(("cmdloop(%d) called\n", top));
241 	setstackmark(&smark);
242 	for (;;) {
243 		if (pendingsigs)
244 			dotrap();
245 		inter = 0;
246 		if (iflag && top) {
247 			inter++;
248 			showjobs(1);
249 			chkmail(0);
250 			flushout(&output);
251 		}
252 		n = parsecmd(inter);
253 		/* showtree(n); DEBUG */
254 		if (n == NEOF) {
255 			if (!top || numeof >= 50)
256 				break;
257 			if (!stoppedjobs()) {
258 				if (!Iflag)
259 					break;
260 				out2str("\nUse \"exit\" to leave shell.\n");
261 			}
262 			numeof++;
263 		} else if (n != NULL && nflag == 0) {
264 			job_warning = (job_warning == 2) ? 1 : 0;
265 			numeof = 0;
266 			evaltree(n, 0);
267 		}
268 		popstackmark(&smark);
269 		if (evalskip == SKIPFILE) {
270 			evalskip = 0;
271 			break;
272 		}
273 	}
274 	popstackmark(&smark);		/* unnecessary */
275 }
276 
277 
278 
279 /*
280  * Read /etc/profile or .profile.  Return on error.
281  */
282 
283 STATIC void
284 read_profile(name)
285 	const char *name;
286 {
287 	int fd;
288 	int xflag_set = 0;
289 	int vflag_set = 0;
290 
291 	INTOFF;
292 	if ((fd = open(name, O_RDONLY)) >= 0)
293 		setinputfd(fd, 1);
294 	INTON;
295 	if (fd < 0)
296 		return;
297 	/* -q turns off -x and -v just when executing init files */
298 	if (qflag)  {
299 	    if (xflag)
300 		    xflag = 0, xflag_set = 1;
301 	    if (vflag)
302 		    vflag = 0, vflag_set = 1;
303 	}
304 	cmdloop(0);
305 	if (qflag)  {
306 	    if (xflag_set)
307 		    xflag = 1;
308 	    if (vflag_set)
309 		    vflag = 1;
310 	}
311 	popfile();
312 }
313 
314 
315 
316 /*
317  * Read a file containing shell functions.
318  */
319 
320 void
321 readcmdfile(name)
322 	char *name;
323 {
324 	int fd;
325 
326 	INTOFF;
327 	if ((fd = open(name, O_RDONLY)) >= 0)
328 		setinputfd(fd, 1);
329 	else
330 		error("Can't open %s", name);
331 	INTON;
332 	cmdloop(0);
333 	popfile();
334 }
335 
336 
337 
338 /*
339  * Take commands from a file.  To be compatable we should do a path
340  * search for the file, which is necessary to find sub-commands.
341  */
342 
343 
344 STATIC char *
345 find_dot_file(basename)
346 	char *basename;
347 {
348 	char *fullname;
349 	const char *path = pathval();
350 	struct stat statb;
351 
352 	/* don't try this for absolute or relative paths */
353 	if (strchr(basename, '/'))
354 		return basename;
355 
356 	while ((fullname = padvance(&path, basename)) != NULL) {
357 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
358 			/*
359 			 * Don't bother freeing here, since it will
360 			 * be freed by the caller.
361 			 */
362 			return fullname;
363 		}
364 		stunalloc(fullname);
365 	}
366 
367 	/* not found in the PATH */
368 	error("%s: not found", basename);
369 	/* NOTREACHED */
370 }
371 
372 int
373 dotcmd(argc, argv)
374 	int argc;
375 	char **argv;
376 {
377 	struct strlist *sp;
378 	exitstatus = 0;
379 
380 	for (sp = cmdenviron; sp ; sp = sp->next)
381 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
382 
383 	if (argc >= 2) {		/* That's what SVR2 does */
384 		char *fullname;
385 		struct stackmark smark;
386 
387 		setstackmark(&smark);
388 		fullname = find_dot_file(argv[1]);
389 		setinputfile(fullname, 1);
390 		commandname = fullname;
391 		cmdloop(0);
392 		popfile();
393 		popstackmark(&smark);
394 	}
395 	return exitstatus;
396 }
397 
398 
399 int
400 exitcmd(argc, argv)
401 	int argc;
402 	char **argv;
403 {
404 	extern int oexitstatus;
405 
406 	if (stoppedjobs())
407 		return 0;
408 	if (argc > 1)
409 		exitstatus = number(argv[1]);
410 	else
411 		exitstatus = oexitstatus;
412 	exitshell(exitstatus);
413 	/* NOTREACHED */
414 }
415