xref: /freebsd/bin/sh/main.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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 int localeisutf8, initial_localeisutf8;
80 
81 static void read_profile(const char *);
82 static char *find_dot_file(char *);
83 
84 /*
85  * Main routine.  We initialize things, parse the arguments, execute
86  * profiles if we're a login shell, and then call cmdloop to execute
87  * commands.  The setjmp call sets up the location to jump to when an
88  * exception occurs.  When an exception occurs the variable "state"
89  * is used to figure out how far we had gotten.
90  */
91 
92 int
93 main(int argc, char *argv[])
94 {
95 	struct stackmark smark;
96 	volatile int state;
97 	char *shinit;
98 
99 	(void) setlocale(LC_ALL, "");
100 	initcharset();
101 	state = 0;
102 	if (setjmp(main_handler.loc)) {
103 		switch (exception) {
104 		case EXEXEC:
105 			exitstatus = exerrno;
106 			break;
107 
108 		case EXERROR:
109 			exitstatus = 2;
110 			break;
111 
112 		default:
113 			break;
114 		}
115 
116 		if (state == 0 || iflag == 0 || ! rootshell ||
117 		    exception == EXEXIT)
118 			exitshell(exitstatus);
119 		reset();
120 		if (exception == EXINT)
121 			out2fmt_flush("\n");
122 		popstackmark(&smark);
123 		FORCEINTON;				/* enable interrupts */
124 		if (state == 1)
125 			goto state1;
126 		else if (state == 2)
127 			goto state2;
128 		else if (state == 3)
129 			goto state3;
130 		else
131 			goto state4;
132 	}
133 	handler = &main_handler;
134 #ifdef DEBUG
135 	opentrace();
136 	trputs("Shell args:  ");  trargs(argv);
137 #endif
138 	rootpid = getpid();
139 	rootshell = 1;
140 	init();
141 	setstackmark(&smark);
142 	procargs(argc, argv);
143 	pwd_init(iflag);
144 	if (iflag)
145 		chkmail(1);
146 	if (argv[0] && argv[0][0] == '-') {
147 		state = 1;
148 		read_profile("/etc/profile");
149 state1:
150 		state = 2;
151 		if (privileged == 0)
152 			read_profile(".profile");
153 		else
154 			read_profile("/etc/suid_profile");
155 	}
156 state2:
157 	state = 3;
158 	if (!privileged && iflag) {
159 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
160 			state = 3;
161 			read_profile(shinit);
162 		}
163 	}
164 state3:
165 	state = 4;
166 	if (minusc) {
167 		evalstring(minusc, sflag ? 0 : EV_EXIT);
168 	}
169 	if (sflag || minusc == NULL) {
170 state4:	/* XXX ??? - why isn't this before the "if" statement */
171 		cmdloop(1);
172 	}
173 	exitshell(exitstatus);
174 	/*NOTREACHED*/
175 	return 0;
176 }
177 
178 
179 /*
180  * Read and execute commands.  "Top" is nonzero for the top level command
181  * loop; it turns on prompting if the shell is interactive.
182  */
183 
184 void
185 cmdloop(int top)
186 {
187 	union node *n;
188 	struct stackmark smark;
189 	int inter;
190 	int numeof = 0;
191 
192 	TRACE(("cmdloop(%d) called\n", top));
193 	setstackmark(&smark);
194 	for (;;) {
195 		if (pendingsigs)
196 			dotrap();
197 		inter = 0;
198 		if (iflag && top) {
199 			inter++;
200 			showjobs(1, SHOWJOBS_DEFAULT);
201 			chkmail(0);
202 			flushout(&output);
203 		}
204 		n = parsecmd(inter);
205 		/* showtree(n); DEBUG */
206 		if (n == NEOF) {
207 			if (!top || numeof >= 50)
208 				break;
209 			if (!stoppedjobs()) {
210 				if (!Iflag)
211 					break;
212 				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
213 			}
214 			numeof++;
215 		} else if (n != NULL && nflag == 0) {
216 			job_warning = (job_warning == 2) ? 1 : 0;
217 			numeof = 0;
218 			evaltree(n, 0);
219 		}
220 		popstackmark(&smark);
221 		setstackmark(&smark);
222 		if (evalskip != 0) {
223 			if (evalskip == SKIPFILE)
224 				evalskip = 0;
225 			break;
226 		}
227 	}
228 	popstackmark(&smark);
229 }
230 
231 
232 
233 /*
234  * Read /etc/profile or .profile.  Return on error.
235  */
236 
237 static void
238 read_profile(const char *name)
239 {
240 	int fd;
241 
242 	INTOFF;
243 	if ((fd = open(name, O_RDONLY)) >= 0)
244 		setinputfd(fd, 1);
245 	INTON;
246 	if (fd < 0)
247 		return;
248 	cmdloop(0);
249 	popfile();
250 }
251 
252 
253 
254 /*
255  * Read a file containing shell functions.
256  */
257 
258 void
259 readcmdfile(const char *name)
260 {
261 	int fd;
262 
263 	INTOFF;
264 	if ((fd = open(name, O_RDONLY)) >= 0)
265 		setinputfd(fd, 1);
266 	else
267 		error("cannot open %s: %s", name, strerror(errno));
268 	INTON;
269 	cmdloop(0);
270 	popfile();
271 }
272 
273 
274 
275 /*
276  * Take commands from a file.  To be compatible we should do a path
277  * search for the file, which is necessary to find sub-commands.
278  */
279 
280 
281 static char *
282 find_dot_file(char *basename)
283 {
284 	char *fullname;
285 	const char *path = pathval();
286 	struct stat statb;
287 
288 	/* don't try this for absolute or relative paths */
289 	if( strchr(basename, '/'))
290 		return basename;
291 
292 	while ((fullname = padvance(&path, basename)) != NULL) {
293 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
294 			/*
295 			 * Don't bother freeing here, since it will
296 			 * be freed by the caller.
297 			 */
298 			return fullname;
299 		}
300 		stunalloc(fullname);
301 	}
302 	return basename;
303 }
304 
305 int
306 dotcmd(int argc, char **argv)
307 {
308 	char *filename, *fullname;
309 
310 	if (argc < 2)
311 		error("missing filename");
312 
313 	exitstatus = 0;
314 
315 	/*
316 	 * Because we have historically not supported any options,
317 	 * only treat "--" specially.
318 	 */
319 	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
320 
321 	fullname = find_dot_file(filename);
322 	setinputfile(fullname, 1);
323 	commandname = fullname;
324 	cmdloop(0);
325 	popfile();
326 	return exitstatus;
327 }
328 
329 
330 int
331 exitcmd(int argc, char **argv)
332 {
333 	if (stoppedjobs())
334 		return 0;
335 	if (argc > 1)
336 		exitshell(number(argv[1]));
337 	else
338 		exitshell_savedstatus();
339 }
340