xref: /dflybsd-src/bin/sh/main.c (revision 48d201a5a8c1dab4aa7166b0812594c101fc43c3)
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 1.3 2004/03/19 18:39:41 cpressey 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 /*
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 jmploc jmploc;
95 	struct stackmark smark;
96 	volatile int state;
97 	char *shinit;
98 
99 #if PROFILE
100 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
101 #endif
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 #if ATTY
137 		 && (! attyset() || equal(termval(), "emacs"))
138 #endif
139 		 ) {
140 			out2c('\n');
141 			flushout(&errout);
142 		}
143 		popstackmark(&smark);
144 		FORCEINTON;				/* enable interrupts */
145 		if (state == 1)
146 			goto state1;
147 		else if (state == 2)
148 			goto state2;
149 		else if (state == 3)
150 			goto state3;
151 		else
152 			goto state4;
153 	}
154 	handler = &jmploc;
155 #ifdef DEBUG
156 	opentrace();
157 	trputs("Shell args:  ");  trargs(argv);
158 #endif
159 	rootpid = getpid();
160 	rootshell = 1;
161 	init();
162 	setstackmark(&smark);
163 	procargs(argc, argv);
164 	if (getpwd() == NULL && iflag)
165 		out2str("sh: cannot determine working directory\n");
166 	if (argv[0] && argv[0][0] == '-') {
167 		state = 1;
168 		read_profile("/etc/profile");
169 state1:
170 		state = 2;
171 		if (privileged == 0)
172 			read_profile(".profile");
173 		else
174 			read_profile("/etc/suid_profile");
175 	}
176 state2:
177 	state = 3;
178 	if (!privileged && iflag) {
179 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
180 			state = 3;
181 			read_profile(shinit);
182 		}
183 	}
184 state3:
185 	state = 4;
186 	if (minusc) {
187 		evalstring(minusc);
188 	}
189 	if (sflag || minusc == NULL) {
190 state4:	/* XXX ??? - why isn't this before the "if" statement */
191 		cmdloop(1);
192 	}
193 #if PROFILE
194 	monitor(0);
195 #endif
196 	exitshell(exitstatus);
197 	/*NOTREACHED*/
198 	return 0;
199 }
200 
201 
202 /*
203  * Read and execute commands.  "Top" is nonzero for the top level command
204  * loop; it turns on prompting if the shell is interactive.
205  */
206 
207 void
208 cmdloop(int top)
209 {
210 	union node *n;
211 	struct stackmark smark;
212 	int inter;
213 	int numeof = 0;
214 
215 	TRACE(("cmdloop(%d) called\n", top));
216 	setstackmark(&smark);
217 	for (;;) {
218 		if (pendingsigs)
219 			dotrap();
220 		inter = 0;
221 		if (iflag && top) {
222 			inter++;
223 			showjobs(1, 0, 0);
224 			chkmail(0);
225 			flushout(&output);
226 		}
227 		n = parsecmd(inter);
228 		/* showtree(n); DEBUG */
229 		if (n == NEOF) {
230 			if (!top || numeof >= 50)
231 				break;
232 			if (!stoppedjobs()) {
233 				if (!Iflag)
234 					break;
235 				out2str("\nUse \"exit\" to leave shell.\n");
236 			}
237 			numeof++;
238 		} else if (n != NULL && nflag == 0) {
239 			job_warning = (job_warning == 2) ? 1 : 0;
240 			numeof = 0;
241 			evaltree(n, 0);
242 		}
243 		popstackmark(&smark);
244 		setstackmark(&smark);
245 		if (evalskip == SKIPFILE) {
246 			evalskip = 0;
247 			break;
248 		}
249 	}
250 	popstackmark(&smark);
251 }
252 
253 
254 
255 /*
256  * Read /etc/profile or .profile.  Return on error.
257  */
258 
259 STATIC void
260 read_profile(const char *name)
261 {
262 	int fd;
263 
264 	INTOFF;
265 	if ((fd = open(name, O_RDONLY)) >= 0)
266 		setinputfd(fd, 1);
267 	INTON;
268 	if (fd < 0)
269 		return;
270 	cmdloop(0);
271 	popfile();
272 }
273 
274 
275 
276 /*
277  * Read a file containing shell functions.
278  */
279 
280 void
281 readcmdfile(char *name)
282 {
283 	int fd;
284 
285 	INTOFF;
286 	if ((fd = open(name, O_RDONLY)) >= 0)
287 		setinputfd(fd, 1);
288 	else
289 		error("Can't open %s: %s", name, strerror(errno));
290 	INTON;
291 	cmdloop(0);
292 	popfile();
293 }
294 
295 
296 
297 /*
298  * Take commands from a file.  To be compatible we should do a path
299  * search for the file, which is necessary to find sub-commands.
300  */
301 
302 
303 STATIC const char *
304 find_dot_file(const char *basename)
305 {
306 	static char localname[FILENAME_MAX+1];
307 	char *fullname;
308 	const char *path = pathval();
309 	struct stat statb;
310 
311 	/* don't try this for absolute or relative paths */
312 	if( strchr(basename, '/'))
313 		return basename;
314 
315 	while ((fullname = padvance(&path, basename)) != NULL) {
316 		strcpy(localname, fullname);
317 		stunalloc(fullname);
318 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
319 			return localname;
320 	}
321 	return basename;
322 }
323 
324 int
325 dotcmd(int argc, char **argv)
326 {
327 	struct strlist *sp;
328 	exitstatus = 0;
329 
330 	for (sp = cmdenviron; sp ; sp = sp->next)
331 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
332 
333 	if (argc >= 2) {		/* That's what SVR2 does */
334 		const char *fullname = find_dot_file(argv[1]);
335 
336 		setinputfile(fullname, 1);
337 		commandname = fullname;
338 		cmdloop(0);
339 		popfile();
340 	}
341 	return exitstatus;
342 }
343 
344 
345 int
346 exitcmd(int argc, char **argv)
347 {
348 	extern int oexitstatus;
349 
350 	if (stoppedjobs())
351 		return 0;
352 	if (argc > 1)
353 		exitstatus = number(argv[1]);
354 	else
355 		exitstatus = oexitstatus;
356 	exitshell(exitstatus);
357 	/*NOTREACHED*/
358 	return 0;
359 }
360