xref: /dragonfly/bin/sh/main.c (revision 97fe2313)
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  * @(#) Copyright (c) 1991, 1993 The Regents of the University of California.  All rights reserved.
37  * @(#)main.c	8.6 (Berkeley) 5/28/95
38  * $FreeBSD: src/bin/sh/main.c,v 1.49 2011/06/04 15:05:52 jilles Exp $
39  */
40 
41 #include <stdio.h>
42 #include <signal.h>
43 #include <sys/stat.h>
44 #include <unistd.h>
45 #include <fcntl.h>
46 #include <locale.h>
47 #include <errno.h>
48 
49 #include "shell.h"
50 #include "main.h"
51 #include "mail.h"
52 #include "options.h"
53 #include "output.h"
54 #include "parser.h"
55 #include "nodes.h"
56 #include "expand.h"
57 #include "eval.h"
58 #include "jobs.h"
59 #include "input.h"
60 #include "trap.h"
61 #include "var.h"
62 #include "show.h"
63 #include "memalloc.h"
64 #include "error.h"
65 #include "init.h"
66 #include "mystring.h"
67 #include "exec.h"
68 #include "cd.h"
69 
70 int rootpid;
71 int rootshell;
72 struct jmploc main_handler;
73 int localeisutf8, initial_localeisutf8;
74 
75 static void read_profile(const char *);
76 static const char *find_dot_file(const char *);
77 
78 /*
79  * Main routine.  We initialize things, parse the arguments, execute
80  * profiles if we're a login shell, and then call cmdloop to execute
81  * commands.  The setjmp call sets up the location to jump to when an
82  * exception occurs.  When an exception occurs the variable "state"
83  * is used to figure out how far we had gotten.
84  */
85 
86 int
87 main(int argc, char *argv[])
88 {
89 	struct stackmark smark;
90 	volatile int state;
91 	char *shinit;
92 
93 	setlocale(LC_ALL, "");
94 	initcharset();
95 	state = 0;
96 	if (setjmp(main_handler.loc)) {
97 		switch (exception) {
98 		case EXEXEC:
99 			exitstatus = exerrno;
100 			break;
101 
102 		case EXERROR:
103 			exitstatus = 2;
104 			break;
105 
106 		default:
107 			break;
108 		}
109 
110 		if (state == 0 || iflag == 0 || ! rootshell ||
111 		    exception == EXEXIT)
112 			exitshell(exitstatus);
113 		reset();
114 		if (exception == EXINT)
115 			out2fmt_flush("\n");
116 		popstackmark(&smark);
117 		FORCEINTON;				/* enable interrupts */
118 		if (state == 1)
119 			goto state1;
120 		else if (state == 2)
121 			goto state2;
122 		else if (state == 3)
123 			goto state3;
124 		else
125 			goto state4;
126 	}
127 	handler = &main_handler;
128 #ifdef DEBUG
129 	opentrace();
130 	trputs("Shell args:  ");  trargs(argv);
131 #endif
132 	rootpid = getpid();
133 	rootshell = 1;
134 	init();
135 	setstackmark(&smark);
136 	procargs(argc, argv);
137 	pwd_init(iflag);
138 	if (iflag)
139 		chkmail(1);
140 	if (argv[0] && argv[0][0] == '-') {
141 		state = 1;
142 		read_profile("/etc/profile");
143 state1:
144 		state = 2;
145 		if (privileged == 0)
146 			read_profile(".profile");
147 		else
148 			read_profile("/etc/suid_profile");
149 	}
150 state2:
151 	state = 3;
152 	if (!privileged && iflag) {
153 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
154 			state = 3;
155 			read_profile(shinit);
156 		}
157 	}
158 state3:
159 	state = 4;
160 	if (minusc) {
161 		evalstring(minusc, sflag ? 0 : EV_EXIT);
162 	}
163 	if (sflag || minusc == NULL) {
164 state4:	/* XXX ??? - why isn't this before the "if" statement */
165 		cmdloop(1);
166 	}
167 	exitshell(exitstatus);
168 	/*NOTREACHED*/
169 	return 0;
170 }
171 
172 
173 /*
174  * Read and execute commands.  "Top" is nonzero for the top level command
175  * loop; it turns on prompting if the shell is interactive.
176  */
177 
178 void
179 cmdloop(int top)
180 {
181 	union node *n;
182 	struct stackmark smark;
183 	int inter;
184 	int numeof = 0;
185 
186 	TRACE(("cmdloop(%d) called\n", top));
187 	setstackmark(&smark);
188 	for (;;) {
189 		if (pendingsigs)
190 			dotrap();
191 		inter = 0;
192 		if (iflag && top) {
193 			inter++;
194 			showjobs(1, SHOWJOBS_DEFAULT);
195 			chkmail(0);
196 			flushout(&output);
197 		}
198 		n = parsecmd(inter);
199 		/* showtree(n); DEBUG */
200 		if (n == NEOF) {
201 			if (!top || numeof >= 50)
202 				break;
203 			if (!stoppedjobs()) {
204 				if (!Iflag)
205 					break;
206 				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
207 			}
208 			numeof++;
209 		} else if (n != NULL && nflag == 0) {
210 			job_warning = (job_warning == 2) ? 1 : 0;
211 			numeof = 0;
212 			evaltree(n, 0);
213 		}
214 		popstackmark(&smark);
215 		setstackmark(&smark);
216 		if (evalskip != 0) {
217 			if (evalskip == SKIPFILE)
218 				evalskip = 0;
219 			break;
220 		}
221 	}
222 	popstackmark(&smark);
223 }
224 
225 
226 
227 /*
228  * Read /etc/profile or .profile.  Return on error.
229  */
230 
231 static void
232 read_profile(const char *name)
233 {
234 	int fd;
235 
236 	INTOFF;
237 	if ((fd = open(name, O_RDONLY)) >= 0)
238 		setinputfd(fd, 1);
239 	INTON;
240 	if (fd < 0)
241 		return;
242 	cmdloop(0);
243 	popfile();
244 }
245 
246 
247 
248 /*
249  * Read a file containing shell functions.
250  */
251 
252 void
253 readcmdfile(const char *name)
254 {
255 	int fd;
256 
257 	INTOFF;
258 	if ((fd = open(name, O_RDONLY)) >= 0)
259 		setinputfd(fd, 1);
260 	else
261 		error("cannot open %s: %s", name, strerror(errno));
262 	INTON;
263 	cmdloop(0);
264 	popfile();
265 }
266 
267 
268 
269 /*
270  * Take commands from a file.  To be compatible we should do a path
271  * search for the file, which is necessary to find sub-commands.
272  */
273 
274 
275 static const char *
276 find_dot_file(const char *basename)
277 {
278 	char *fullname;
279 	const char *path = pathval();
280 	struct stat statb;
281 
282 	/* don't try this for absolute or relative paths */
283 	if( strchr(basename, '/'))
284 		return basename;
285 
286 	while ((fullname = padvance(&path, basename)) != NULL) {
287 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
288 			/*
289 			 * Don't bother freeing here, since it will
290 			 * be freed by the caller.
291 			 */
292 			return fullname;
293 		}
294 		stunalloc(fullname);
295 	}
296 	return basename;
297 }
298 
299 int
300 dotcmd(int argc, char **argv)
301 {
302 	const char *fullname;
303 	char *filename;
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