xref: /netbsd-src/bin/sh/main.c (revision 81b108b45f75f89f1e3ffad9fb6f074e771c0935)
1 /*	$NetBSD: main.c,v 1.23 1995/11/19 23:27:42 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 1.23 1995/11/19 23:27:42 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 		if (exception == EXERROR)
125 			exitstatus = 2;
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 	getpwd();
164 	if (argv[0] && argv[0][0] == '-') {
165 		state = 1;
166 		read_profile("/etc/profile");
167 state1:
168 		state = 2;
169 		read_profile(".profile");
170 	}
171 state2:
172 	state = 3;
173 	if (getuid() == geteuid() && getgid() == getegid()) {
174 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
175 			state = 3;
176 			read_profile(shinit);
177 		}
178 	}
179 state3:
180 	state = 4;
181 	if (minusc) {
182 		evalstring(minusc);
183 	}
184 	if (sflag || minusc == NULL) {
185 state4:	/* XXX ??? - why isn't this before the "if" statement */
186 		cmdloop(1);
187 	}
188 #if PROFILE
189 	monitor(0);
190 #endif
191 	exitshell(exitstatus);
192 	/*NOTREACHED*/
193 	return 0;
194 }
195 
196 
197 /*
198  * Read and execute commands.  "Top" is nonzero for the top level command
199  * loop; it turns on prompting if the shell is interactive.
200  */
201 
202 void
203 cmdloop(top)
204 	int top;
205 {
206 	union node *n;
207 	struct stackmark smark;
208 	int inter;
209 	int numeof = 0;
210 
211 	TRACE(("cmdloop(%d) called\n", top));
212 	setstackmark(&smark);
213 	for (;;) {
214 		if (pendingsigs)
215 			dotrap();
216 		inter = 0;
217 		if (iflag && top) {
218 			inter++;
219 			showjobs(1);
220 			chkmail(0);
221 			flushout(&output);
222 		}
223 		n = parsecmd(inter);
224 		/* showtree(n); DEBUG */
225 		if (n == NEOF) {
226 			if (!top || numeof >= 50)
227 				break;
228 			if (!stoppedjobs()) {
229 				if (!Iflag)
230 					break;
231 				out2str("\nUse \"exit\" to leave shell.\n");
232 			}
233 			numeof++;
234 		} else if (n != NULL && nflag == 0) {
235 			job_warning = (job_warning == 2) ? 1 : 0;
236 			numeof = 0;
237 			evaltree(n, 0);
238 		}
239 		popstackmark(&smark);
240 		if (evalskip == SKIPFILE) {
241 			evalskip = 0;
242 			break;
243 		}
244 	}
245 	popstackmark(&smark);		/* unnecessary */
246 }
247 
248 
249 
250 /*
251  * Read /etc/profile or .profile.  Return on error.
252  */
253 
254 STATIC void
255 read_profile(name)
256 	char *name;
257 	{
258 	int fd;
259 
260 	INTOFF;
261 	if ((fd = open(name, O_RDONLY)) >= 0)
262 		setinputfd(fd, 1);
263 	INTON;
264 	if (fd < 0)
265 		return;
266 	cmdloop(0);
267 	popfile();
268 }
269 
270 
271 
272 /*
273  * Read a file containing shell functions.
274  */
275 
276 void
277 readcmdfile(name)
278 	char *name;
279 {
280 	int fd;
281 
282 	INTOFF;
283 	if ((fd = open(name, O_RDONLY)) >= 0)
284 		setinputfd(fd, 1);
285 	else
286 		error("Can't open %s", name);
287 	INTON;
288 	cmdloop(0);
289 	popfile();
290 }
291 
292 
293 
294 /*
295  * Take commands from a file.  To be compatable we should do a path
296  * search for the file, which is necessary to find sub-commands.
297  */
298 
299 
300 STATIC char *
301 find_dot_file(basename)
302 	char *basename;
303 {
304 	static char localname[FILENAME_MAX+1];
305 	char *fullname;
306 	char *path = pathval();
307 	struct stat statb;
308 
309 	/* don't try this for absolute or relative paths */
310 	if( strchr(basename, '/'))
311 		return basename;
312 
313 	while ((fullname = padvance(&path, basename)) != NULL) {
314 		strcpy(localname, fullname);
315 		stunalloc(fullname);
316 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
317 			return localname;
318 	}
319 	return basename;
320 }
321 
322 int
323 dotcmd(argc, argv)
324 	int argc;
325 	char **argv;
326 {
327 	struct strlist *sp;
328 	exitstatus = 0;
329 
330 	for (sp = cmdenviron; sp ; sp = sp->next)
331 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
332 
333 	if (argc >= 2) {		/* That's what SVR2 does */
334 		char *fullname = find_dot_file(argv[1]);
335 
336 		setinputfile(fullname, 1);
337 		commandname = fullname;
338 		cmdloop(0);
339 		popfile();
340 	}
341 	return exitstatus;
342 }
343 
344 
345 int
346 exitcmd(argc, argv)
347 	int argc;
348 	char **argv;
349 {
350 	extern int oexitstatus;
351 
352 	if (stoppedjobs())
353 		return 0;
354 	if (argc > 1)
355 		exitstatus = number(argv[1]);
356 	else
357 		exitstatus = oexitstatus;
358 	exitshell(exitstatus);
359 	/*NOTREACHED*/
360 	return 0;
361 }
362 
363 
364 #ifdef notdef
365 /*
366  * Should never be called.
367  */
368 
369 void
370 exit(exitstatus) {
371 	_exit(exitstatus);
372 }
373 #endif
374