xref: /netbsd-src/bin/sh/main.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: main.c,v 1.52 2008/10/16 14:55:28 dholland Exp $	*/
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\
38  The Regents of the University of California.  All rights reserved.");
39 #endif /* not lint */
40 
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)main.c	8.7 (Berkeley) 7/19/95";
44 #else
45 __RCSID("$NetBSD: main.c,v 1.52 2008/10/16 14:55:28 dholland Exp $");
46 #endif
47 #endif /* not lint */
48 
49 #include <errno.h>
50 #include <stdio.h>
51 #include <signal.h>
52 #include <sys/stat.h>
53 #include <unistd.h>
54 #include <locale.h>
55 #include <fcntl.h>
56 
57 
58 #include "shell.h"
59 #include "main.h"
60 #include "mail.h"
61 #include "options.h"
62 #include "output.h"
63 #include "parser.h"
64 #include "nodes.h"
65 #include "expand.h"
66 #include "eval.h"
67 #include "jobs.h"
68 #include "input.h"
69 #include "trap.h"
70 #include "var.h"
71 #include "show.h"
72 #include "memalloc.h"
73 #include "error.h"
74 #include "init.h"
75 #include "mystring.h"
76 #include "exec.h"
77 #include "cd.h"
78 
79 #define PROFILE 0
80 
81 int rootpid;
82 int rootshell;
83 #if PROFILE
84 short profile_buf[16384];
85 extern int etext();
86 #endif
87 
88 STATIC void read_profile(const char *);
89 STATIC char *find_dot_file(char *);
90 int main(int, char **);
91 
92 /*
93  * Main routine.  We initialize things, parse the arguments, execute
94  * profiles if we're a login shell, and then call cmdloop to execute
95  * commands.  The setjmp call sets up the location to jump to when an
96  * exception occurs.  When an exception occurs the variable "state"
97  * is used to figure out how far we had gotten.
98  */
99 
100 int
101 main(int argc, char **argv)
102 {
103 	struct jmploc jmploc;
104 	struct stackmark smark;
105 	volatile int state;
106 	char *shinit;
107 
108 	setlocale(LC_ALL, "");
109 
110 #if PROFILE
111 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
112 #endif
113 	state = 0;
114 	if (setjmp(jmploc.loc)) {
115 		/*
116 		 * When a shell procedure is executed, we raise the
117 		 * exception EXSHELLPROC to clean up before executing
118 		 * the shell procedure.
119 		 */
120 		switch (exception) {
121 		case EXSHELLPROC:
122 			rootpid = getpid();
123 			rootshell = 1;
124 			minusc = NULL;
125 			state = 3;
126 			break;
127 
128 		case EXEXEC:
129 			exitstatus = exerrno;
130 			break;
131 
132 		case EXERROR:
133 			exitstatus = 2;
134 			break;
135 
136 		default:
137 			break;
138 		}
139 
140 		if (exception != EXSHELLPROC) {
141 			if (state == 0 || iflag == 0 || ! rootshell)
142 				exitshell(exitstatus);
143 		}
144 		reset();
145 		if (exception == EXINT
146 #if ATTY
147 		 && (! attyset() || equal(termval(), "emacs"))
148 #endif
149 		 ) {
150 			out2c('\n');
151 			flushout(&errout);
152 		}
153 		popstackmark(&smark);
154 		FORCEINTON;				/* enable interrupts */
155 		if (state == 1)
156 			goto state1;
157 		else if (state == 2)
158 			goto state2;
159 		else if (state == 3)
160 			goto state3;
161 		else
162 			goto state4;
163 	}
164 	handler = &jmploc;
165 #ifdef DEBUG
166 #if DEBUG == 2
167 	debug = 1;
168 #endif
169 	opentrace();
170 	trputs("Shell args:  ");  trargs(argv);
171 #endif
172 	rootpid = getpid();
173 	rootshell = 1;
174 	init();
175 	initpwd();
176 	setstackmark(&smark);
177 	procargs(argc, argv);
178 	if (argv[0] && argv[0][0] == '-') {
179 		state = 1;
180 		read_profile("/etc/profile");
181 state1:
182 		state = 2;
183 		read_profile(".profile");
184 	}
185 state2:
186 	state = 3;
187 	if (getuid() == geteuid() && getgid() == getegid()) {
188 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
189 			state = 3;
190 			read_profile(shinit);
191 		}
192 	}
193 state3:
194 	state = 4;
195 	if (sflag == 0 || minusc) {
196 		static int sigs[] =  {
197 		    SIGINT, SIGQUIT, SIGHUP,
198 #ifdef SIGTSTP
199 		    SIGTSTP,
200 #endif
201 		    SIGPIPE
202 		};
203 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
204 		int i;
205 
206 		for (i = 0; i < SIGSSIZE; i++)
207 		    setsignal(sigs[i], 0);
208 	}
209 
210 	if (minusc)
211 		evalstring(minusc, 0);
212 
213 	if (sflag || minusc == NULL) {
214 state4:	/* XXX ??? - why isn't this before the "if" statement */
215 		cmdloop(1);
216 	}
217 #if PROFILE
218 	monitor(0);
219 #endif
220 	exitshell(exitstatus);
221 	/* NOTREACHED */
222 }
223 
224 
225 /*
226  * Read and execute commands.  "Top" is nonzero for the top level command
227  * loop; it turns on prompting if the shell is interactive.
228  */
229 
230 void
231 cmdloop(int top)
232 {
233 	union node *n;
234 	struct stackmark smark;
235 	int inter;
236 	int numeof = 0;
237 
238 	TRACE(("cmdloop(%d) called\n", top));
239 	setstackmark(&smark);
240 	for (;;) {
241 		if (pendingsigs)
242 			dotrap();
243 		inter = 0;
244 		if (iflag == 1 && top) {
245 			inter = 1;
246 			showjobs(out2, SHOW_CHANGED);
247 			chkmail(0);
248 			flushout(&errout);
249 		}
250 		n = parsecmd(inter);
251 		/* showtree(n); DEBUG */
252 		if (n == NEOF) {
253 			if (!top || numeof >= 50)
254 				break;
255 			if (!stoppedjobs()) {
256 				if (!Iflag)
257 					break;
258 				out2str("\nUse \"exit\" to leave shell.\n");
259 			}
260 			numeof++;
261 		} else if (n != NULL && nflag == 0) {
262 			job_warning = (job_warning == 2) ? 1 : 0;
263 			numeof = 0;
264 			evaltree(n, 0);
265 		}
266 		popstackmark(&smark);
267 		setstackmark(&smark);
268 		if (evalskip == SKIPFILE) {
269 			evalskip = 0;
270 			break;
271 		}
272 	}
273 	popstackmark(&smark);
274 }
275 
276 
277 
278 /*
279  * Read /etc/profile or .profile.  Return on error.
280  */
281 
282 STATIC void
283 read_profile(const char *name)
284 {
285 	int fd;
286 	int xflag_set = 0;
287 	int vflag_set = 0;
288 
289 	INTOFF;
290 	if ((fd = open(name, O_RDONLY)) >= 0)
291 		setinputfd(fd, 1);
292 	INTON;
293 	if (fd < 0)
294 		return;
295 	/* -q turns off -x and -v just when executing init files */
296 	if (qflag)  {
297 	    if (xflag)
298 		    xflag = 0, xflag_set = 1;
299 	    if (vflag)
300 		    vflag = 0, vflag_set = 1;
301 	}
302 	cmdloop(0);
303 	if (qflag)  {
304 	    if (xflag_set)
305 		    xflag = 1;
306 	    if (vflag_set)
307 		    vflag = 1;
308 	}
309 	popfile();
310 }
311 
312 
313 
314 /*
315  * Read a file containing shell functions.
316  */
317 
318 void
319 readcmdfile(char *name)
320 {
321 	int fd;
322 
323 	INTOFF;
324 	if ((fd = open(name, O_RDONLY)) >= 0)
325 		setinputfd(fd, 1);
326 	else
327 		error("Can't open %s", name);
328 	INTON;
329 	cmdloop(0);
330 	popfile();
331 }
332 
333 
334 
335 /*
336  * Take commands from a file.  To be compatible we should do a path
337  * search for the file, which is necessary to find sub-commands.
338  */
339 
340 
341 STATIC char *
342 find_dot_file(char *basename)
343 {
344 	char *fullname;
345 	const char *path = pathval();
346 	struct stat statb;
347 
348 	/* don't try this for absolute or relative paths */
349 	if (strchr(basename, '/'))
350 		return basename;
351 
352 	while ((fullname = padvance(&path, basename)) != NULL) {
353 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
354 			/*
355 			 * Don't bother freeing here, since it will
356 			 * be freed by the caller.
357 			 */
358 			return fullname;
359 		}
360 		stunalloc(fullname);
361 	}
362 
363 	/* not found in the PATH */
364 	error("%s: not found", basename);
365 	/* NOTREACHED */
366 }
367 
368 int
369 dotcmd(int argc, char **argv)
370 {
371 	exitstatus = 0;
372 
373 	if (argc >= 2) {		/* That's what SVR2 does */
374 		char *fullname;
375 		struct stackmark smark;
376 
377 		setstackmark(&smark);
378 		fullname = find_dot_file(argv[1]);
379 		setinputfile(fullname, 1);
380 		commandname = fullname;
381 		cmdloop(0);
382 		popfile();
383 		popstackmark(&smark);
384 	}
385 	return exitstatus;
386 }
387 
388 
389 int
390 exitcmd(int argc, char **argv)
391 {
392 	if (stoppedjobs())
393 		return 0;
394 	if (argc > 1)
395 		exitstatus = number(argv[1]);
396 	exitshell(exitstatus);
397 	/* NOTREACHED */
398 }
399