xref: /freebsd/bin/sh/main.c (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992)
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 			exitshell(exitstatus);
116 		reset();
117 		if (exception == EXINT)
118 			out2fmt_flush("\n");
119 		popstackmark(&smark);
120 		FORCEINTON;				/* enable interrupts */
121 		if (state == 1)
122 			goto state1;
123 		else if (state == 2)
124 			goto state2;
125 		else if (state == 3)
126 			goto state3;
127 		else
128 			goto state4;
129 	}
130 	handler = &main_handler;
131 #ifdef DEBUG
132 	opentrace();
133 	trputs("Shell args:  ");  trargs(argv);
134 #endif
135 	rootpid = getpid();
136 	rootshell = 1;
137 	init();
138 	setstackmark(&smark);
139 	procargs(argc, argv);
140 	pwd_init(iflag);
141 	if (iflag)
142 		chkmail(1);
143 	if (argv[0] && argv[0][0] == '-') {
144 		state = 1;
145 		read_profile("/etc/profile");
146 state1:
147 		state = 2;
148 		if (privileged == 0)
149 			read_profile(".profile");
150 		else
151 			read_profile("/etc/suid_profile");
152 	}
153 state2:
154 	state = 3;
155 	if (!privileged && iflag) {
156 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
157 			state = 3;
158 			read_profile(shinit);
159 		}
160 	}
161 state3:
162 	state = 4;
163 	if (minusc) {
164 		evalstring(minusc, sflag ? 0 : EV_EXIT);
165 	}
166 	if (sflag || minusc == NULL) {
167 state4:	/* XXX ??? - why isn't this before the "if" statement */
168 		cmdloop(1);
169 	}
170 	exitshell(exitstatus);
171 	/*NOTREACHED*/
172 	return 0;
173 }
174 
175 
176 /*
177  * Read and execute commands.  "Top" is nonzero for the top level command
178  * loop; it turns on prompting if the shell is interactive.
179  */
180 
181 void
182 cmdloop(int top)
183 {
184 	union node *n;
185 	struct stackmark smark;
186 	int inter;
187 	int numeof = 0;
188 
189 	TRACE(("cmdloop(%d) called\n", top));
190 	setstackmark(&smark);
191 	for (;;) {
192 		if (pendingsigs)
193 			dotrap();
194 		inter = 0;
195 		if (iflag && top) {
196 			inter++;
197 			showjobs(1, SHOWJOBS_DEFAULT);
198 			chkmail(0);
199 			flushout(&output);
200 		}
201 		n = parsecmd(inter);
202 		/* showtree(n); DEBUG */
203 		if (n == NEOF) {
204 			if (!top || numeof >= 50)
205 				break;
206 			if (!stoppedjobs()) {
207 				if (!Iflag)
208 					break;
209 				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
210 			}
211 			numeof++;
212 		} else if (n != NULL && nflag == 0) {
213 			job_warning = (job_warning == 2) ? 1 : 0;
214 			numeof = 0;
215 			evaltree(n, 0);
216 		}
217 		popstackmark(&smark);
218 		setstackmark(&smark);
219 		if (evalskip != 0) {
220 			if (evalskip == SKIPFILE)
221 				evalskip = 0;
222 			break;
223 		}
224 	}
225 	popstackmark(&smark);
226 }
227 
228 
229 
230 /*
231  * Read /etc/profile or .profile.  Return on error.
232  */
233 
234 static void
235 read_profile(const char *name)
236 {
237 	int fd;
238 
239 	INTOFF;
240 	if ((fd = open(name, O_RDONLY)) >= 0)
241 		setinputfd(fd, 1);
242 	INTON;
243 	if (fd < 0)
244 		return;
245 	cmdloop(0);
246 	popfile();
247 }
248 
249 
250 
251 /*
252  * Read a file containing shell functions.
253  */
254 
255 void
256 readcmdfile(const char *name)
257 {
258 	int fd;
259 
260 	INTOFF;
261 	if ((fd = open(name, O_RDONLY)) >= 0)
262 		setinputfd(fd, 1);
263 	else
264 		error("Can't open %s: %s", name, strerror(errno));
265 	INTON;
266 	cmdloop(0);
267 	popfile();
268 }
269 
270 
271 
272 /*
273  * Take commands from a file.  To be compatible we should do a path
274  * search for the file, which is necessary to find sub-commands.
275  */
276 
277 
278 static char *
279 find_dot_file(char *basename)
280 {
281 	static char localname[FILENAME_MAX+1];
282 	char *fullname;
283 	const char *path = pathval();
284 	struct stat statb;
285 
286 	/* don't try this for absolute or relative paths */
287 	if( strchr(basename, '/'))
288 		return basename;
289 
290 	while ((fullname = padvance(&path, basename)) != NULL) {
291 		strcpy(localname, fullname);
292 		stunalloc(fullname);
293 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
294 			return localname;
295 	}
296 	return basename;
297 }
298 
299 int
300 dotcmd(int argc, char **argv)
301 {
302 	char *filename, *fullname;
303 
304 	if (argc < 2)
305 		error("missing filename");
306 
307 	exitstatus = 0;
308 
309 	/*
310 	 * Because we have historically not supported any options,
311 	 * only treat "--" specially.
312 	 */
313 	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
314 
315 	fullname = find_dot_file(filename);
316 	setinputfile(fullname, 1);
317 	commandname = fullname;
318 	cmdloop(0);
319 	popfile();
320 	return exitstatus;
321 }
322 
323 
324 int
325 exitcmd(int argc, char **argv)
326 {
327 	if (stoppedjobs())
328 		return 0;
329 	if (argc > 1)
330 		exitshell(number(argv[1]));
331 	else
332 		exitshell_savedstatus();
333 }
334