xref: /freebsd/bin/sh/main.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
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 
37 #ifndef lint
38 static char const copyright[] =
39 "@(#) Copyright (c) 1991, 1993\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)main.c	8.6 (Berkeley) 5/28/95";
46 #endif
47 #endif /* not lint */
48 #include <sys/cdefs.h>
49 __FBSDID("$FreeBSD$");
50 
51 #include <stdio.h>
52 #include <signal.h>
53 #include <sys/stat.h>
54 #include <unistd.h>
55 #include <fcntl.h>
56 #include <locale.h>
57 #include <errno.h>
58 
59 #include "shell.h"
60 #include "main.h"
61 #include "mail.h"
62 #include "options.h"
63 #include "output.h"
64 #include "parser.h"
65 #include "nodes.h"
66 #include "expand.h"
67 #include "eval.h"
68 #include "jobs.h"
69 #include "input.h"
70 #include "trap.h"
71 #include "var.h"
72 #include "show.h"
73 #include "memalloc.h"
74 #include "error.h"
75 #include "init.h"
76 #include "mystring.h"
77 #include "exec.h"
78 #include "cd.h"
79 
80 int rootpid;
81 int rootshell;
82 
83 STATIC void read_profile(char *);
84 STATIC char *find_dot_file(char *);
85 
86 /*
87  * Main routine.  We initialize things, parse the arguments, execute
88  * profiles if we're a login shell, and then call cmdloop to execute
89  * commands.  The setjmp call sets up the location to jump to when an
90  * exception occurs.  When an exception occurs the variable "state"
91  * is used to figure out how far we had gotten.
92  */
93 
94 int
95 main(int argc, char *argv[])
96 {
97 	struct jmploc jmploc;
98 	struct stackmark smark;
99 	volatile int state;
100 	char *shinit;
101 
102 	(void) setlocale(LC_ALL, "");
103 	state = 0;
104 	if (setjmp(jmploc.loc)) {
105 		/*
106 		 * When a shell procedure is executed, we raise the
107 		 * exception EXSHELLPROC to clean up before executing
108 		 * the shell procedure.
109 		 */
110 		switch (exception) {
111 		case EXSHELLPROC:
112 			rootpid = getpid();
113 			rootshell = 1;
114 			minusc = NULL;
115 			state = 3;
116 			break;
117 
118 		case EXEXEC:
119 			exitstatus = exerrno;
120 			break;
121 
122 		case EXERROR:
123 			exitstatus = 2;
124 			break;
125 
126 		default:
127 			break;
128 		}
129 
130 		if (exception != EXSHELLPROC) {
131 		    if (state == 0 || iflag == 0 || ! rootshell)
132 			    exitshell(exitstatus);
133 		}
134 		reset();
135 		if (exception == EXINT) {
136 			out2c('\n');
137 			flushout(&errout);
138 		}
139 		popstackmark(&smark);
140 		FORCEINTON;				/* enable interrupts */
141 		if (state == 1)
142 			goto state1;
143 		else if (state == 2)
144 			goto state2;
145 		else if (state == 3)
146 			goto state3;
147 		else
148 			goto state4;
149 	}
150 	handler = &jmploc;
151 #ifdef DEBUG
152 	opentrace();
153 	trputs("Shell args:  ");  trargs(argv);
154 #endif
155 	rootpid = getpid();
156 	rootshell = 1;
157 	init();
158 	setstackmark(&smark);
159 	procargs(argc, argv);
160 	if (getpwd() == NULL && iflag)
161 		out2str("sh: cannot determine working directory\n");
162 	if (argv[0] && argv[0][0] == '-') {
163 		state = 1;
164 		read_profile("/etc/profile");
165 state1:
166 		state = 2;
167 		if (privileged == 0)
168 			read_profile(".profile");
169 		else
170 			read_profile("/etc/suid_profile");
171 	}
172 state2:
173 	state = 3;
174 	if (!privileged && iflag) {
175 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
176 			state = 3;
177 			read_profile(shinit);
178 		}
179 	}
180 state3:
181 	state = 4;
182 	if (minusc) {
183 		evalstring(minusc);
184 	}
185 	if (sflag || minusc == NULL) {
186 state4:	/* XXX ??? - why isn't this before the "if" statement */
187 		cmdloop(1);
188 	}
189 	exitshell(exitstatus);
190 	/*NOTREACHED*/
191 	return 0;
192 }
193 
194 
195 /*
196  * Read and execute commands.  "Top" is nonzero for the top level command
197  * loop; it turns on prompting if the shell is interactive.
198  */
199 
200 void
201 cmdloop(int top)
202 {
203 	union node *n;
204 	struct stackmark smark;
205 	int inter;
206 	int numeof = 0;
207 
208 	TRACE(("cmdloop(%d) called\n", top));
209 	setstackmark(&smark);
210 	for (;;) {
211 		if (pendingsigs)
212 			dotrap();
213 		inter = 0;
214 		if (iflag && top) {
215 			inter++;
216 			showjobs(1, 0, 0);
217 			chkmail(0);
218 			flushout(&output);
219 		}
220 		n = parsecmd(inter);
221 		/* showtree(n); DEBUG */
222 		if (n == NEOF) {
223 			if (!top || numeof >= 50)
224 				break;
225 			if (!stoppedjobs()) {
226 				if (!Iflag)
227 					break;
228 				out2str("\nUse \"exit\" to leave shell.\n");
229 			}
230 			numeof++;
231 		} else if (n != NULL && nflag == 0) {
232 			job_warning = (job_warning == 2) ? 1 : 0;
233 			numeof = 0;
234 			evaltree(n, 0);
235 		}
236 		popstackmark(&smark);
237 		setstackmark(&smark);
238 		if (evalskip == SKIPFILE) {
239 			evalskip = 0;
240 			break;
241 		}
242 	}
243 	popstackmark(&smark);
244 }
245 
246 
247 
248 /*
249  * Read /etc/profile or .profile.  Return on error.
250  */
251 
252 STATIC void
253 read_profile(char *name)
254 {
255 	int fd;
256 
257 	INTOFF;
258 	if ((fd = open(name, O_RDONLY)) >= 0)
259 		setinputfd(fd, 1);
260 	INTON;
261 	if (fd < 0)
262 		return;
263 	cmdloop(0);
264 	popfile();
265 }
266 
267 
268 
269 /*
270  * Read a file containing shell functions.
271  */
272 
273 void
274 readcmdfile(char *name)
275 {
276 	int fd;
277 
278 	INTOFF;
279 	if ((fd = open(name, O_RDONLY)) >= 0)
280 		setinputfd(fd, 1);
281 	else
282 		error("Can't open %s: %s", name, strerror(errno));
283 	INTON;
284 	cmdloop(0);
285 	popfile();
286 }
287 
288 
289 
290 /*
291  * Take commands from a file.  To be compatible we should do a path
292  * search for the file, which is necessary to find sub-commands.
293  */
294 
295 
296 STATIC char *
297 find_dot_file(char *basename)
298 {
299 	static char localname[FILENAME_MAX+1];
300 	char *fullname;
301 	char *path = pathval();
302 	struct stat statb;
303 
304 	/* don't try this for absolute or relative paths */
305 	if( strchr(basename, '/'))
306 		return basename;
307 
308 	while ((fullname = padvance(&path, basename)) != NULL) {
309 		strcpy(localname, fullname);
310 		stunalloc(fullname);
311 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
312 			return localname;
313 	}
314 	return basename;
315 }
316 
317 int
318 dotcmd(int argc, char **argv)
319 {
320 	struct strlist *sp;
321 	exitstatus = 0;
322 
323 	for (sp = cmdenviron; sp ; sp = sp->next)
324 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
325 
326 	if (argc >= 2) {		/* That's what SVR2 does */
327 		char *fullname = find_dot_file(argv[1]);
328 
329 		setinputfile(fullname, 1);
330 		commandname = fullname;
331 		cmdloop(0);
332 		popfile();
333 	}
334 	return exitstatus;
335 }
336 
337 
338 int
339 exitcmd(int argc, char **argv)
340 {
341 	extern int oexitstatus;
342 
343 	if (stoppedjobs())
344 		return 0;
345 	if (argc > 1)
346 		exitstatus = number(argv[1]);
347 	else
348 		exitstatus = oexitstatus;
349 	exitshell(exitstatus);
350 	/*NOTREACHED*/
351 	return 0;
352 }
353