xref: /freebsd/bin/sh/main.c (revision 380a989b3223d455375b4fae70fd0b9bdd43bafb)
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 const 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 #if 0
45 static char sccsid[] = "@(#)main.c	8.6 (Berkeley) 5/28/95";
46 #endif
47 static const char rcsid[] =
48 	"$Id$";
49 #endif /* not lint */
50 
51 #include <stdio.h>
52 #include <signal.h>
53 #include <sys/stat.h>
54 #include <unistd.h>
55 #include <fcntl.h>
56 #include <locale.h>
57 
58 
59 #include "shell.h"
60 #include "main.h"
61 #include "mail.h"
62 #include "options.h"
63 #include "output.h"
64 #include "parser.h"
65 #include "nodes.h"
66 #include "expand.h"
67 #include "eval.h"
68 #include "jobs.h"
69 #include "input.h"
70 #include "trap.h"
71 #include "var.h"
72 #include "show.h"
73 #include "memalloc.h"
74 #include "error.h"
75 #include "init.h"
76 #include "mystring.h"
77 #include "exec.h"
78 #include "cd.h"
79 
80 #define PROFILE 0
81 
82 int rootpid;
83 int rootshell;
84 extern int errno;
85 #if PROFILE
86 short profile_buf[16384];
87 extern int etext();
88 #endif
89 
90 STATIC void read_profile __P((char *));
91 STATIC char *find_dot_file __P((char *));
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 	(void) setlocale(LC_ALL, "");
115 	state = 0;
116 	if (setjmp(jmploc.loc)) {
117 		/*
118 		 * When a shell procedure is executed, we raise the
119 		 * exception EXSHELLPROC to clean up before executing
120 		 * the shell procedure.
121 		 */
122 		switch (exception) {
123 		case EXSHELLPROC:
124 			rootpid = getpid();
125 			rootshell = 1;
126 			minusc = NULL;
127 			state = 3;
128 			break;
129 
130 		case EXEXEC:
131 			exitstatus = exerrno;
132 			break;
133 
134 		case EXERROR:
135 			exitstatus = 2;
136 			break;
137 
138 		default:
139 			break;
140 		}
141 
142 		if (exception != EXSHELLPROC) {
143 		    if (state == 0 || iflag == 0 || ! rootshell)
144 			    exitshell(exitstatus);
145 		}
146 		reset();
147 		if (exception == EXINT
148 #if ATTY
149 		 && (! attyset() || equal(termval(), "emacs"))
150 #endif
151 		 ) {
152 			out2c('\n');
153 			flushout(&errout);
154 		}
155 		popstackmark(&smark);
156 		FORCEINTON;				/* enable interrupts */
157 		if (state == 1)
158 			goto state1;
159 		else if (state == 2)
160 			goto state2;
161 		else if (state == 3)
162 			goto state3;
163 		else
164 			goto state4;
165 	}
166 	handler = &jmploc;
167 #ifdef DEBUG
168 	opentrace();
169 	trputs("Shell args:  ");  trargs(argv);
170 #endif
171 	rootpid = getpid();
172 	rootshell = 1;
173 	init();
174 	setstackmark(&smark);
175 	procargs(argc, argv);
176 	if (getpwd() == NULL && iflag)
177 		out2str("sh: cannot determine working directory\n");
178 	if (argv[0] && argv[0][0] == '-') {
179 		state = 1;
180 		read_profile("/etc/profile");
181 state1:
182 		state = 2;
183 		if (privileged == 0)
184 			read_profile(".profile");
185 		else
186 			read_profile("/etc/suid_profile");
187 	}
188 state2:
189 	state = 3;
190 	if (!privileged && iflag) {
191 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
192 			state = 3;
193 			read_profile(shinit);
194 		}
195 	}
196 state3:
197 	state = 4;
198 	if (minusc) {
199 		evalstring(minusc);
200 	}
201 	if (sflag || minusc == NULL) {
202 state4:	/* XXX ??? - why isn't this before the "if" statement */
203 		cmdloop(1);
204 	}
205 #if PROFILE
206 	monitor(0);
207 #endif
208 	exitshell(exitstatus);
209 	/*NOTREACHED*/
210 	return 0;
211 }
212 
213 
214 /*
215  * Read and execute commands.  "Top" is nonzero for the top level command
216  * loop; it turns on prompting if the shell is interactive.
217  */
218 
219 void
220 cmdloop(top)
221 	int top;
222 {
223 	union node *n;
224 	struct stackmark smark;
225 	int inter;
226 	int numeof = 0;
227 
228 	TRACE(("cmdloop(%d) called\n", top));
229 	setstackmark(&smark);
230 	for (;;) {
231 		if (pendingsigs)
232 			dotrap();
233 		inter = 0;
234 		if (iflag && top) {
235 			inter++;
236 			showjobs(1);
237 			chkmail(0);
238 			flushout(&output);
239 		}
240 		n = parsecmd(inter);
241 		/* showtree(n); DEBUG */
242 		if (n == NEOF) {
243 			if (!top || numeof >= 50)
244 				break;
245 			if (!stoppedjobs()) {
246 				if (!Iflag)
247 					break;
248 				out2str("\nUse \"exit\" to leave shell.\n");
249 			}
250 			numeof++;
251 		} else if (n != NULL && nflag == 0) {
252 			job_warning = (job_warning == 2) ? 1 : 0;
253 			numeof = 0;
254 			evaltree(n, 0);
255 		}
256 		popstackmark(&smark);
257 		if (evalskip == SKIPFILE) {
258 			evalskip = 0;
259 			break;
260 		}
261 	}
262 	popstackmark(&smark);		/* unnecessary */
263 }
264 
265 
266 
267 /*
268  * Read /etc/profile or .profile.  Return on error.
269  */
270 
271 STATIC void
272 read_profile(name)
273 	char *name;
274 	{
275 	int fd;
276 
277 	INTOFF;
278 	if ((fd = open(name, O_RDONLY)) >= 0)
279 		setinputfd(fd, 1);
280 	INTON;
281 	if (fd < 0)
282 		return;
283 	cmdloop(0);
284 	popfile();
285 }
286 
287 
288 
289 /*
290  * Read a file containing shell functions.
291  */
292 
293 void
294 readcmdfile(name)
295 	char *name;
296 {
297 	int fd;
298 
299 	INTOFF;
300 	if ((fd = open(name, O_RDONLY)) >= 0)
301 		setinputfd(fd, 1);
302 	else
303 		error("Can't open %s", name);
304 	INTON;
305 	cmdloop(0);
306 	popfile();
307 }
308 
309 
310 
311 /*
312  * Take commands from a file.  To be compatable we should do a path
313  * search for the file, which is necessary to find sub-commands.
314  */
315 
316 
317 STATIC char *
318 find_dot_file(basename)
319 	char *basename;
320 {
321 	static char localname[FILENAME_MAX+1];
322 	char *fullname;
323 	char *path = pathval();
324 	struct stat statb;
325 
326 	/* don't try this for absolute or relative paths */
327 	if( strchr(basename, '/'))
328 		return basename;
329 
330 	while ((fullname = padvance(&path, basename)) != NULL) {
331 		strcpy(localname, fullname);
332 		stunalloc(fullname);
333 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
334 			return localname;
335 	}
336 	return basename;
337 }
338 
339 int
340 dotcmd(argc, argv)
341 	int argc;
342 	char **argv;
343 {
344 	struct strlist *sp;
345 	exitstatus = 0;
346 
347 	for (sp = cmdenviron; sp ; sp = sp->next)
348 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
349 
350 	if (argc >= 2) {		/* That's what SVR2 does */
351 		char *fullname = find_dot_file(argv[1]);
352 
353 		setinputfile(fullname, 1);
354 		commandname = fullname;
355 		cmdloop(0);
356 		popfile();
357 	}
358 	return exitstatus;
359 }
360 
361 
362 int
363 exitcmd(argc, argv)
364 	int argc;
365 	char **argv;
366 {
367 	extern int oexitstatus;
368 
369 	if (stoppedjobs())
370 		return 0;
371 	if (argc > 1)
372 		exitstatus = number(argv[1]);
373 	else
374 		exitstatus = oexitstatus;
375 	exitshell(exitstatus);
376 	/*NOTREACHED*/
377 	return 0;
378 }
379 
380 
381 #ifdef notdef
382 /*
383  * Should never be called.
384  */
385 
386 void
387 exit(exitstatus) {
388 	_exit(exitstatus);
389 }
390 #endif
391