xref: /freebsd/bin/sh/main.c (revision 48855ec75316aaec5538ef22132f96fd04e137d4)
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  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static char const copyright[] =
35 "@(#) Copyright (c) 1991, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)main.c	8.6 (Berkeley) 5/28/95";
42 #endif
43 #endif /* not lint */
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <stdio.h>
48 #include <signal.h>
49 #include <sys/stat.h>
50 #include <unistd.h>
51 #include <fcntl.h>
52 #include <locale.h>
53 #include <errno.h>
54 
55 #include "shell.h"
56 #include "main.h"
57 #include "mail.h"
58 #include "options.h"
59 #include "output.h"
60 #include "parser.h"
61 #include "nodes.h"
62 #include "expand.h"
63 #include "eval.h"
64 #include "jobs.h"
65 #include "input.h"
66 #include "trap.h"
67 #include "var.h"
68 #include "show.h"
69 #include "memalloc.h"
70 #include "error.h"
71 #include "init.h"
72 #include "mystring.h"
73 #include "exec.h"
74 #include "cd.h"
75 
76 int rootpid;
77 int rootshell;
78 struct jmploc main_handler;
79 
80 static void read_profile(const char *);
81 static char *find_dot_file(char *);
82 
83 /*
84  * Main routine.  We initialize things, parse the arguments, execute
85  * profiles if we're a login shell, and then call cmdloop to execute
86  * commands.  The setjmp call sets up the location to jump to when an
87  * exception occurs.  When an exception occurs the variable "state"
88  * is used to figure out how far we had gotten.
89  */
90 
91 int
92 main(int argc, char *argv[])
93 {
94 	struct stackmark smark;
95 	volatile int state;
96 	char *shinit;
97 
98 	(void) setlocale(LC_ALL, "");
99 	state = 0;
100 	if (setjmp(main_handler.loc)) {
101 		switch (exception) {
102 		case EXEXEC:
103 			exitstatus = exerrno;
104 			break;
105 
106 		case EXERROR:
107 			exitstatus = 2;
108 			break;
109 
110 		default:
111 			break;
112 		}
113 
114 		if (state == 0 || iflag == 0 || ! rootshell ||
115 		    exception == EXEXIT)
116 			exitshell(exitstatus);
117 		reset();
118 		if (exception == EXINT)
119 			out2fmt_flush("\n");
120 		popstackmark(&smark);
121 		FORCEINTON;				/* enable interrupts */
122 		if (state == 1)
123 			goto state1;
124 		else if (state == 2)
125 			goto state2;
126 		else if (state == 3)
127 			goto state3;
128 		else
129 			goto state4;
130 	}
131 	handler = &main_handler;
132 #ifdef DEBUG
133 	opentrace();
134 	trputs("Shell args:  ");  trargs(argv);
135 #endif
136 	rootpid = getpid();
137 	rootshell = 1;
138 	init();
139 	setstackmark(&smark);
140 	procargs(argc, argv);
141 	pwd_init(iflag);
142 	if (iflag)
143 		chkmail(1);
144 	if (argv[0] && argv[0][0] == '-') {
145 		state = 1;
146 		read_profile("/etc/profile");
147 state1:
148 		state = 2;
149 		if (privileged == 0)
150 			read_profile(".profile");
151 		else
152 			read_profile("/etc/suid_profile");
153 	}
154 state2:
155 	state = 3;
156 	if (!privileged && iflag) {
157 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
158 			state = 3;
159 			read_profile(shinit);
160 		}
161 	}
162 state3:
163 	state = 4;
164 	if (minusc) {
165 		evalstring(minusc, sflag ? 0 : EV_EXIT);
166 	}
167 	if (sflag || minusc == NULL) {
168 state4:	/* XXX ??? - why isn't this before the "if" statement */
169 		cmdloop(1);
170 	}
171 	exitshell(exitstatus);
172 	/*NOTREACHED*/
173 	return 0;
174 }
175 
176 
177 /*
178  * Read and execute commands.  "Top" is nonzero for the top level command
179  * loop; it turns on prompting if the shell is interactive.
180  */
181 
182 void
183 cmdloop(int top)
184 {
185 	union node *n;
186 	struct stackmark smark;
187 	int inter;
188 	int numeof = 0;
189 
190 	TRACE(("cmdloop(%d) called\n", top));
191 	setstackmark(&smark);
192 	for (;;) {
193 		if (pendingsigs)
194 			dotrap();
195 		inter = 0;
196 		if (iflag && top) {
197 			inter++;
198 			showjobs(1, SHOWJOBS_DEFAULT);
199 			chkmail(0);
200 			flushout(&output);
201 		}
202 		n = parsecmd(inter);
203 		/* showtree(n); DEBUG */
204 		if (n == NEOF) {
205 			if (!top || numeof >= 50)
206 				break;
207 			if (!stoppedjobs()) {
208 				if (!Iflag)
209 					break;
210 				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
211 			}
212 			numeof++;
213 		} else if (n != NULL && nflag == 0) {
214 			job_warning = (job_warning == 2) ? 1 : 0;
215 			numeof = 0;
216 			evaltree(n, 0);
217 		}
218 		popstackmark(&smark);
219 		setstackmark(&smark);
220 		if (evalskip != 0) {
221 			if (evalskip == SKIPFILE)
222 				evalskip = 0;
223 			break;
224 		}
225 	}
226 	popstackmark(&smark);
227 }
228 
229 
230 
231 /*
232  * Read /etc/profile or .profile.  Return on error.
233  */
234 
235 static void
236 read_profile(const char *name)
237 {
238 	int fd;
239 
240 	INTOFF;
241 	if ((fd = open(name, O_RDONLY)) >= 0)
242 		setinputfd(fd, 1);
243 	INTON;
244 	if (fd < 0)
245 		return;
246 	cmdloop(0);
247 	popfile();
248 }
249 
250 
251 
252 /*
253  * Read a file containing shell functions.
254  */
255 
256 void
257 readcmdfile(const char *name)
258 {
259 	int fd;
260 
261 	INTOFF;
262 	if ((fd = open(name, O_RDONLY)) >= 0)
263 		setinputfd(fd, 1);
264 	else
265 		error("Can't open %s: %s", name, strerror(errno));
266 	INTON;
267 	cmdloop(0);
268 	popfile();
269 }
270 
271 
272 
273 /*
274  * Take commands from a file.  To be compatible we should do a path
275  * search for the file, which is necessary to find sub-commands.
276  */
277 
278 
279 static char *
280 find_dot_file(char *basename)
281 {
282 	static char localname[FILENAME_MAX+1];
283 	char *fullname;
284 	const char *path = pathval();
285 	struct stat statb;
286 
287 	/* don't try this for absolute or relative paths */
288 	if( strchr(basename, '/'))
289 		return basename;
290 
291 	while ((fullname = padvance(&path, basename)) != NULL) {
292 		strcpy(localname, fullname);
293 		stunalloc(fullname);
294 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
295 			return localname;
296 	}
297 	return basename;
298 }
299 
300 int
301 dotcmd(int argc, char **argv)
302 {
303 	char *filename, *fullname;
304 
305 	if (argc < 2)
306 		error("missing filename");
307 
308 	exitstatus = 0;
309 
310 	/*
311 	 * Because we have historically not supported any options,
312 	 * only treat "--" specially.
313 	 */
314 	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
315 
316 	fullname = find_dot_file(filename);
317 	setinputfile(fullname, 1);
318 	commandname = fullname;
319 	cmdloop(0);
320 	popfile();
321 	return exitstatus;
322 }
323 
324 
325 int
326 exitcmd(int argc, char **argv)
327 {
328 	if (stoppedjobs())
329 		return 0;
330 	if (argc > 1)
331 		exitshell(number(argv[1]));
332 	else
333 		exitshell_savedstatus();
334 }
335