xref: /freebsd/bin/sh/main.c (revision 8ce070c1b28cd5f33c098da43378d0239091bd00)
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 #include "builtins.h"
76 
77 int rootpid;
78 int rootshell;
79 struct jmploc main_handler;
80 int localeisutf8, initial_localeisutf8;
81 
82 static void read_profile(char *);
83 static char *find_dot_file(char *);
84 
85 /*
86  * Main routine.  We initialize things, parse the arguments, execute
87  * profiles if we're a login shell, and then call cmdloop to execute
88  * commands.  The setjmp call sets up the location to jump to when an
89  * exception occurs.  When an exception occurs the variable "state"
90  * is used to figure out how far we had gotten.
91  */
92 
93 int
94 main(int argc, char *argv[])
95 {
96 	struct stackmark smark, smark2;
97 	volatile int state;
98 	char *shinit;
99 
100 	(void) setlocale(LC_ALL, "");
101 	initcharset();
102 	state = 0;
103 	if (setjmp(main_handler.loc)) {
104 		switch (exception) {
105 		case EXEXEC:
106 			exitstatus = exerrno;
107 			break;
108 
109 		case EXERROR:
110 			exitstatus = 2;
111 			break;
112 
113 		default:
114 			break;
115 		}
116 
117 		if (state == 0 || iflag == 0 || ! rootshell ||
118 		    exception == EXEXIT)
119 			exitshell(exitstatus);
120 		reset();
121 		if (exception == EXINT)
122 			out2fmt_flush("\n");
123 		popstackmark(&smark);
124 		FORCEINTON;				/* enable interrupts */
125 		if (state == 1)
126 			goto state1;
127 		else if (state == 2)
128 			goto state2;
129 		else if (state == 3)
130 			goto state3;
131 		else
132 			goto state4;
133 	}
134 	handler = &main_handler;
135 #ifdef DEBUG
136 	opentrace();
137 	trputs("Shell args:  ");  trargs(argv);
138 #endif
139 	rootpid = getpid();
140 	rootshell = 1;
141 	init();
142 	setstackmark(&smark);
143 	setstackmark(&smark2);
144 	procargs(argc, argv);
145 	pwd_init(iflag);
146 	if (iflag)
147 		chkmail(1);
148 	if (argv[0] && argv[0][0] == '-') {
149 		state = 1;
150 		read_profile("/etc/profile");
151 state1:
152 		state = 2;
153 		if (privileged == 0)
154 			read_profile("${HOME-}/.profile");
155 		else
156 			read_profile("/etc/suid_profile");
157 	}
158 state2:
159 	state = 3;
160 	if (!privileged && iflag) {
161 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
162 			state = 3;
163 			read_profile(shinit);
164 		}
165 	}
166 state3:
167 	state = 4;
168 	popstackmark(&smark2);
169 	if (minusc) {
170 		evalstring(minusc, sflag ? 0 : EV_EXIT);
171 	}
172 	if (sflag || minusc == NULL) {
173 state4:	/* XXX ??? - why isn't this before the "if" statement */
174 		cmdloop(1);
175 	}
176 	exitshell(exitstatus);
177 	/*NOTREACHED*/
178 	return 0;
179 }
180 
181 
182 /*
183  * Read and execute commands.  "Top" is nonzero for the top level command
184  * loop; it turns on prompting if the shell is interactive.
185  */
186 
187 void
188 cmdloop(int top)
189 {
190 	union node *n;
191 	struct stackmark smark;
192 	int inter;
193 	int numeof = 0;
194 
195 	TRACE(("cmdloop(%d) called\n", top));
196 	setstackmark(&smark);
197 	for (;;) {
198 		if (pendingsigs)
199 			dotrap();
200 		inter = 0;
201 		if (iflag && top) {
202 			inter++;
203 			showjobs(1, SHOWJOBS_DEFAULT);
204 			chkmail(0);
205 			flushout(&output);
206 		}
207 		n = parsecmd(inter);
208 		/* showtree(n); DEBUG */
209 		if (n == NEOF) {
210 			if (!top || numeof >= 50)
211 				break;
212 			if (!stoppedjobs()) {
213 				if (!Iflag)
214 					break;
215 				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
216 			}
217 			numeof++;
218 		} else if (n != NULL && nflag == 0) {
219 			job_warning = (job_warning == 2) ? 1 : 0;
220 			numeof = 0;
221 			evaltree(n, 0);
222 		}
223 		popstackmark(&smark);
224 		setstackmark(&smark);
225 		if (evalskip != 0) {
226 			if (evalskip == SKIPFILE)
227 				evalskip = 0;
228 			break;
229 		}
230 	}
231 	popstackmark(&smark);
232 }
233 
234 
235 
236 /*
237  * Read /etc/profile or .profile.  Return on error.
238  */
239 
240 static void
241 read_profile(char *name)
242 {
243 	int fd;
244 	const char *expandedname;
245 
246 	expandedname = expandstr(name);
247 	if (expandedname == NULL)
248 		return;
249 	INTOFF;
250 	if ((fd = open(expandedname, O_RDONLY)) >= 0)
251 		setinputfd(fd, 1);
252 	INTON;
253 	if (fd < 0)
254 		return;
255 	cmdloop(0);
256 	popfile();
257 }
258 
259 
260 
261 /*
262  * Read a file containing shell functions.
263  */
264 
265 void
266 readcmdfile(const char *name)
267 {
268 	int fd;
269 
270 	INTOFF;
271 	if ((fd = open(name, O_RDONLY)) >= 0)
272 		setinputfd(fd, 1);
273 	else
274 		error("cannot open %s: %s", name, strerror(errno));
275 	INTON;
276 	cmdloop(0);
277 	popfile();
278 }
279 
280 
281 
282 /*
283  * Take commands from a file.  To be compatible we should do a path
284  * search for the file, which is necessary to find sub-commands.
285  */
286 
287 
288 static char *
289 find_dot_file(char *basename)
290 {
291 	char *fullname;
292 	const char *path = pathval();
293 	struct stat statb;
294 
295 	/* don't try this for absolute or relative paths */
296 	if( strchr(basename, '/'))
297 		return basename;
298 
299 	while ((fullname = padvance(&path, basename)) != NULL) {
300 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
301 			/*
302 			 * Don't bother freeing here, since it will
303 			 * be freed by the caller.
304 			 */
305 			return fullname;
306 		}
307 		stunalloc(fullname);
308 	}
309 	return basename;
310 }
311 
312 int
313 dotcmd(int argc, char **argv)
314 {
315 	char *filename, *fullname;
316 
317 	if (argc < 2)
318 		error("missing filename");
319 
320 	exitstatus = 0;
321 
322 	/*
323 	 * Because we have historically not supported any options,
324 	 * only treat "--" specially.
325 	 */
326 	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
327 
328 	fullname = find_dot_file(filename);
329 	setinputfile(fullname, 1);
330 	commandname = fullname;
331 	cmdloop(0);
332 	popfile();
333 	return exitstatus;
334 }
335 
336 
337 int
338 exitcmd(int argc, char **argv)
339 {
340 	if (stoppedjobs())
341 		return 0;
342 	if (argc > 1)
343 		exitshell(number(argv[1]));
344 	else
345 		exitshell_savedstatus();
346 }
347