xref: /netbsd-src/bin/sh/main.c (revision d0fed6c87ddc40a8bffa6f99e7433ddfc864dd83)
1 /*	$NetBSD: main.c,v 1.25 1997/04/11 23:01:44 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 #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	8.7 (Berkeley) 7/19/95";
48 #else
49 static char rcsid[] = "$NetBSD: main.c,v 1.25 1997/04/11 23:01:44 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 
96 /*
97  * Main routine.  We initialize things, parse the arguments, execute
98  * profiles if we're a login shell, and then call cmdloop to execute
99  * commands.  The setjmp call sets up the location to jump to when an
100  * exception occurs.  When an exception occurs the variable "state"
101  * is used to figure out how far we had gotten.
102  */
103 
104 int
105 main(argc, argv)
106 	int argc;
107 	char **argv;
108 {
109 	struct jmploc jmploc;
110 	struct stackmark smark;
111 	volatile int state;
112 	char *shinit;
113 
114 #if PROFILE
115 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
116 #endif
117 	state = 0;
118 	if (setjmp(jmploc.loc)) {
119 		/*
120 		 * When a shell procedure is executed, we raise the
121 		 * exception EXSHELLPROC to clean up before executing
122 		 * the shell procedure.
123 		 */
124 		switch (exception) {
125 		case EXSHELLPROC:
126 			rootpid = getpid();
127 			rootshell = 1;
128 			minusc = NULL;
129 			state = 3;
130 			break;
131 
132 		case EXEXEC:
133 			exitstatus = exerrno;
134 			break;
135 
136 		case EXERROR:
137 			exitstatus = 2;
138 			break;
139 
140 		default:
141 			break;
142 		}
143 
144 		if (exception != EXSHELLPROC) {
145 		    if (state == 0 || iflag == 0 || ! rootshell)
146 			    exitshell(exitstatus);
147 		}
148 		reset();
149 		if (exception == EXINT
150 #if ATTY
151 		 && (! attyset() || equal(termval(), "emacs"))
152 #endif
153 		 ) {
154 			out2c('\n');
155 			flushout(&errout);
156 		}
157 		popstackmark(&smark);
158 		FORCEINTON;				/* enable interrupts */
159 		if (state == 1)
160 			goto state1;
161 		else if (state == 2)
162 			goto state2;
163 		else if (state == 3)
164 			goto state3;
165 		else
166 			goto state4;
167 	}
168 	handler = &jmploc;
169 #ifdef DEBUG
170 	opentrace();
171 	trputs("Shell args:  ");  trargs(argv);
172 #endif
173 	rootpid = getpid();
174 	rootshell = 1;
175 	init();
176 	setstackmark(&smark);
177 	procargs(argc, argv);
178 	if (argv[0] && argv[0][0] == '-') {
179 		state = 1;
180 		read_profile("/etc/profile");
181 state1:
182 		state = 2;
183 		read_profile(".profile");
184 	}
185 state2:
186 	state = 3;
187 	if (getuid() == geteuid() && getgid() == getegid()) {
188 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
189 			state = 3;
190 			read_profile(shinit);
191 		}
192 	}
193 state3:
194 	state = 4;
195 	if (minusc) {
196 		evalstring(minusc);
197 	}
198 	if (sflag || minusc == NULL) {
199 state4:	/* XXX ??? - why isn't this before the "if" statement */
200 		cmdloop(1);
201 	}
202 #if PROFILE
203 	monitor(0);
204 #endif
205 	exitshell(exitstatus);
206 	/*NOTREACHED*/
207 	return 0;
208 }
209 
210 
211 /*
212  * Read and execute commands.  "Top" is nonzero for the top level command
213  * loop; it turns on prompting if the shell is interactive.
214  */
215 
216 void
217 cmdloop(top)
218 	int top;
219 {
220 	union node *n;
221 	struct stackmark smark;
222 	int inter;
223 	int numeof = 0;
224 
225 	TRACE(("cmdloop(%d) called\n", top));
226 	setstackmark(&smark);
227 	for (;;) {
228 		if (pendingsigs)
229 			dotrap();
230 		inter = 0;
231 		if (iflag && top) {
232 			inter++;
233 			showjobs(1);
234 			chkmail(0);
235 			flushout(&output);
236 		}
237 		n = parsecmd(inter);
238 		/* showtree(n); DEBUG */
239 		if (n == NEOF) {
240 			if (!top || numeof >= 50)
241 				break;
242 			if (!stoppedjobs()) {
243 				if (!Iflag)
244 					break;
245 				out2str("\nUse \"exit\" to leave shell.\n");
246 			}
247 			numeof++;
248 		} else if (n != NULL && nflag == 0) {
249 			job_warning = (job_warning == 2) ? 1 : 0;
250 			numeof = 0;
251 			evaltree(n, 0);
252 		}
253 		popstackmark(&smark);
254 		if (evalskip == SKIPFILE) {
255 			evalskip = 0;
256 			break;
257 		}
258 	}
259 	popstackmark(&smark);		/* unnecessary */
260 }
261 
262 
263 
264 /*
265  * Read /etc/profile or .profile.  Return on error.
266  */
267 
268 STATIC void
269 read_profile(name)
270 	char *name;
271 	{
272 	int fd;
273 
274 	INTOFF;
275 	if ((fd = open(name, O_RDONLY)) >= 0)
276 		setinputfd(fd, 1);
277 	INTON;
278 	if (fd < 0)
279 		return;
280 	cmdloop(0);
281 	popfile();
282 }
283 
284 
285 
286 /*
287  * Read a file containing shell functions.
288  */
289 
290 void
291 readcmdfile(name)
292 	char *name;
293 {
294 	int fd;
295 
296 	INTOFF;
297 	if ((fd = open(name, O_RDONLY)) >= 0)
298 		setinputfd(fd, 1);
299 	else
300 		error("Can't open %s", name);
301 	INTON;
302 	cmdloop(0);
303 	popfile();
304 }
305 
306 
307 
308 /*
309  * Take commands from a file.  To be compatable we should do a path
310  * search for the file, which is necessary to find sub-commands.
311  */
312 
313 
314 STATIC char *
315 find_dot_file(basename)
316 	char *basename;
317 {
318 	static char localname[FILENAME_MAX+1];
319 	char *fullname;
320 	char *path = pathval();
321 	struct stat statb;
322 
323 	/* don't try this for absolute or relative paths */
324 	if( strchr(basename, '/'))
325 		return basename;
326 
327 	while ((fullname = padvance(&path, basename)) != NULL) {
328 		strcpy(localname, fullname);
329 		stunalloc(fullname);
330 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
331 			return localname;
332 	}
333 	return basename;
334 }
335 
336 int
337 dotcmd(argc, argv)
338 	int argc;
339 	char **argv;
340 {
341 	struct strlist *sp;
342 	exitstatus = 0;
343 
344 	for (sp = cmdenviron; sp ; sp = sp->next)
345 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
346 
347 	if (argc >= 2) {		/* That's what SVR2 does */
348 		char *fullname = find_dot_file(argv[1]);
349 
350 		setinputfile(fullname, 1);
351 		commandname = fullname;
352 		cmdloop(0);
353 		popfile();
354 	}
355 	return exitstatus;
356 }
357 
358 
359 int
360 exitcmd(argc, argv)
361 	int argc;
362 	char **argv;
363 {
364 	extern int oexitstatus;
365 
366 	if (stoppedjobs())
367 		return 0;
368 	if (argc > 1)
369 		exitstatus = number(argv[1]);
370 	else
371 		exitstatus = oexitstatus;
372 	exitshell(exitstatus);
373 	/*NOTREACHED*/
374 	return 0;
375 }
376 
377 
378 #ifdef notdef
379 /*
380  * Should never be called.
381  */
382 
383 void
384 exit(exitstatus) {
385 	_exit(exitstatus);
386 }
387 #endif
388