xref: /dflybsd-src/bin/sh/main.c (revision 1f7ab7c9fc18f47a2f16dc45b13dee254c603ce7)
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 1.18.2.3 2002/07/19 04:38:51 tjr Exp $
39  * $DragonFly: src/bin/sh/main.c,v 1.6 2006/09/28 22:29:44 pavalos Exp $
40  */
41 
42 #include <stdio.h>
43 #include <signal.h>
44 #include <sys/stat.h>
45 #include <unistd.h>
46 #include <fcntl.h>
47 #include <locale.h>
48 #include <errno.h>
49 
50 #include "shell.h"
51 #include "main.h"
52 #include "mail.h"
53 #include "options.h"
54 #include "output.h"
55 #include "parser.h"
56 #include "nodes.h"
57 #include "expand.h"
58 #include "eval.h"
59 #include "jobs.h"
60 #include "input.h"
61 #include "trap.h"
62 #include "var.h"
63 #include "show.h"
64 #include "memalloc.h"
65 #include "error.h"
66 #include "init.h"
67 #include "mystring.h"
68 #include "exec.h"
69 #include "cd.h"
70 
71 #define PROFILE 0
72 
73 int rootpid;
74 int rootshell;
75 #if PROFILE
76 short profile_buf[16384];
77 extern int etext();
78 #endif
79 
80 STATIC void read_profile(const char *);
81 STATIC const char *find_dot_file(const char *);
82 
83 extern int oexitstatus;
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 jmploc jmploc;
97 	struct stackmark smark;
98 	volatile int state;
99 	char *shinit;
100 
101 #if PROFILE
102 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
103 #endif
104 	setlocale(LC_ALL, "");
105 	state = 0;
106 	if (setjmp(jmploc.loc)) {
107 		/*
108 		 * When a shell procedure is executed, we raise the
109 		 * exception EXSHELLPROC to clean up before executing
110 		 * the shell procedure.
111 		 */
112 		switch (exception) {
113 		case EXSHELLPROC:
114 			rootpid = getpid();
115 			rootshell = 1;
116 			minusc = NULL;
117 			state = 3;
118 			break;
119 
120 		case EXEXEC:
121 			exitstatus = exerrno;
122 			break;
123 
124 		case EXERROR:
125 			exitstatus = 2;
126 			break;
127 
128 		default:
129 			break;
130 		}
131 
132 		if (exception != EXSHELLPROC) {
133 		    if (state == 0 || iflag == 0 || ! rootshell)
134 			    exitshell(exitstatus);
135 		}
136 		reset();
137 		if (exception == EXINT) {
138 			out2c('\n');
139 			flushout(&errout);
140 		}
141 		popstackmark(&smark);
142 		FORCEINTON;				/* enable interrupts */
143 		if (state == 1)
144 			goto state1;
145 		else if (state == 2)
146 			goto state2;
147 		else if (state == 3)
148 			goto state3;
149 		else
150 			goto state4;
151 	}
152 	handler = &jmploc;
153 #ifdef DEBUG
154 	opentrace();
155 	trputs("Shell args:  ");  trargs(argv);
156 #endif
157 	rootpid = getpid();
158 	rootshell = 1;
159 	init();
160 	setstackmark(&smark);
161 	procargs(argc, argv);
162 	if (getpwd() == NULL && iflag)
163 		out2str("sh: cannot determine working directory\n");
164 	if (argv[0] && argv[0][0] == '-') {
165 		state = 1;
166 		read_profile("/etc/profile");
167 state1:
168 		state = 2;
169 		if (privileged == 0)
170 			read_profile(".profile");
171 		else
172 			read_profile("/etc/suid_profile");
173 	}
174 state2:
175 	state = 3;
176 	if (!privileged && iflag) {
177 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
178 			state = 3;
179 			read_profile(shinit);
180 		}
181 	}
182 state3:
183 	state = 4;
184 	if (minusc) {
185 		evalstring(minusc);
186 	}
187 	if (sflag || minusc == NULL) {
188 state4:	/* XXX ??? - why isn't this before the "if" statement */
189 		cmdloop(1);
190 	}
191 #if PROFILE
192 	monitor(0);
193 #endif
194 	exitshell(exitstatus);
195 	/*NOTREACHED*/
196 	return 0;
197 }
198 
199 
200 /*
201  * Read and execute commands.  "Top" is nonzero for the top level command
202  * loop; it turns on prompting if the shell is interactive.
203  */
204 
205 void
206 cmdloop(int top)
207 {
208 	union node *n;
209 	struct stackmark smark;
210 	int inter;
211 	int numeof = 0;
212 
213 	TRACE(("cmdloop(%d) called\n", top));
214 	setstackmark(&smark);
215 	for (;;) {
216 		if (pendingsigs)
217 			dotrap();
218 		inter = 0;
219 		if (iflag && top) {
220 			inter++;
221 			showjobs(1, 0, 0);
222 			chkmail(0);
223 			flushout(&output);
224 		}
225 		n = parsecmd(inter);
226 		/* showtree(n); DEBUG */
227 		if (n == NEOF) {
228 			if (!top || numeof >= 50)
229 				break;
230 			if (!stoppedjobs()) {
231 				if (!Iflag)
232 					break;
233 				out2str("\nUse \"exit\" to leave shell.\n");
234 			}
235 			numeof++;
236 		} else if (n != NULL && nflag == 0) {
237 			job_warning = (job_warning == 2) ? 1 : 0;
238 			numeof = 0;
239 			evaltree(n, 0);
240 		}
241 		popstackmark(&smark);
242 		setstackmark(&smark);
243 		if (evalskip == SKIPFILE) {
244 			evalskip = 0;
245 			break;
246 		}
247 	}
248 	popstackmark(&smark);
249 }
250 
251 
252 
253 /*
254  * Read /etc/profile or .profile.  Return on error.
255  */
256 
257 STATIC void
258 read_profile(const char *name)
259 {
260 	int fd;
261 
262 	INTOFF;
263 	if ((fd = open(name, O_RDONLY)) >= 0)
264 		setinputfd(fd, 1);
265 	INTON;
266 	if (fd < 0)
267 		return;
268 	cmdloop(0);
269 	popfile();
270 }
271 
272 
273 
274 /*
275  * Read a file containing shell functions.
276  */
277 
278 void
279 readcmdfile(char *name)
280 {
281 	int fd;
282 
283 	INTOFF;
284 	if ((fd = open(name, O_RDONLY)) >= 0)
285 		setinputfd(fd, 1);
286 	else
287 		error("Can't open %s: %s", name, strerror(errno));
288 	INTON;
289 	cmdloop(0);
290 	popfile();
291 }
292 
293 
294 
295 /*
296  * Take commands from a file.  To be compatible we should do a path
297  * search for the file, which is necessary to find sub-commands.
298  */
299 
300 
301 STATIC const char *
302 find_dot_file(const char *basename)
303 {
304 	static char localname[FILENAME_MAX+1];
305 	char *fullname;
306 	const char *path = pathval();
307 	struct stat statb;
308 
309 	/* don't try this for absolute or relative paths */
310 	if( strchr(basename, '/'))
311 		return basename;
312 
313 	while ((fullname = padvance(&path, basename)) != NULL) {
314 		strcpy(localname, fullname);
315 		stunalloc(fullname);
316 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
317 			return localname;
318 	}
319 	return basename;
320 }
321 
322 int
323 dotcmd(int argc, char **argv)
324 {
325 	struct strlist *sp;
326 	exitstatus = 0;
327 
328 	for (sp = cmdenviron; sp ; sp = sp->next)
329 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
330 
331 	if (argc >= 2) {		/* That's what SVR2 does */
332 		const char *fullname = find_dot_file(argv[1]);
333 
334 		setinputfile(fullname, 1);
335 		commandname = fullname;
336 		cmdloop(0);
337 		popfile();
338 	}
339 	return exitstatus;
340 }
341 
342 
343 int
344 exitcmd(int argc, char **argv)
345 {
346 	if (stoppedjobs())
347 		return 0;
348 	if (argc > 1)
349 		exitstatus = number(argv[1]);
350 	else
351 		exitstatus = oexitstatus;
352 	exitshell(exitstatus);
353 	/*NOTREACHED*/
354 	return 0;
355 }
356