xref: /netbsd-src/bin/sh/main.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: main.c,v 1.46 2002/12/11 19:12:18 christos 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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #ifndef lint
41 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\n\
42 	The Regents of the University of California.  All rights reserved.\n");
43 #endif /* not lint */
44 
45 #ifndef lint
46 #if 0
47 static char sccsid[] = "@(#)main.c	8.7 (Berkeley) 7/19/95";
48 #else
49 __RCSID("$NetBSD: main.c,v 1.46 2002/12/11 19:12:18 christos Exp $");
50 #endif
51 #endif /* not lint */
52 
53 #include <errno.h>
54 #include <stdio.h>
55 #include <signal.h>
56 #include <sys/stat.h>
57 #include <unistd.h>
58 #include <locale.h>
59 #include <fcntl.h>
60 
61 
62 #include "shell.h"
63 #include "main.h"
64 #include "mail.h"
65 #include "options.h"
66 #include "output.h"
67 #include "parser.h"
68 #include "nodes.h"
69 #include "expand.h"
70 #include "eval.h"
71 #include "jobs.h"
72 #include "input.h"
73 #include "trap.h"
74 #include "var.h"
75 #include "show.h"
76 #include "memalloc.h"
77 #include "error.h"
78 #include "init.h"
79 #include "mystring.h"
80 #include "exec.h"
81 #include "cd.h"
82 
83 #define PROFILE 0
84 
85 int rootpid;
86 int rootshell;
87 STATIC union node *curcmd;
88 STATIC union node *prevcmd;
89 #if PROFILE
90 short profile_buf[16384];
91 extern int etext();
92 #endif
93 
94 STATIC void read_profile(const char *);
95 STATIC char *find_dot_file(char *);
96 int main(int, char **);
97 
98 /*
99  * Main routine.  We initialize things, parse the arguments, execute
100  * profiles if we're a login shell, and then call cmdloop to execute
101  * commands.  The setjmp call sets up the location to jump to when an
102  * exception occurs.  When an exception occurs the variable "state"
103  * is used to figure out how far we had gotten.
104  */
105 
106 int
107 main(int argc, char **argv)
108 {
109 	struct jmploc jmploc;
110 	struct stackmark smark;
111 	volatile int state;
112 	char *shinit;
113 
114 	setlocale(LC_ALL, "");
115 
116 #if PROFILE
117 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
118 #endif
119 	state = 0;
120 	if (setjmp(jmploc.loc)) {
121 		/*
122 		 * When a shell procedure is executed, we raise the
123 		 * exception EXSHELLPROC to clean up before executing
124 		 * the shell procedure.
125 		 */
126 		switch (exception) {
127 		case EXSHELLPROC:
128 			rootpid = getpid();
129 			rootshell = 1;
130 			minusc = NULL;
131 			state = 3;
132 			break;
133 
134 		case EXEXEC:
135 			exitstatus = exerrno;
136 			break;
137 
138 		case EXERROR:
139 			exitstatus = 2;
140 			break;
141 
142 		default:
143 			break;
144 		}
145 
146 		if (exception != EXSHELLPROC) {
147 			if (state == 0 || iflag == 0 || ! rootshell)
148 				exitshell(exitstatus);
149 		}
150 		reset();
151 		if (exception == EXINT
152 #if ATTY
153 		 && (! attyset() || equal(termval(), "emacs"))
154 #endif
155 		 ) {
156 			out2c('\n');
157 			flushout(&errout);
158 		}
159 		popstackmark(&smark);
160 		FORCEINTON;				/* enable interrupts */
161 		if (state == 1)
162 			goto state1;
163 		else if (state == 2)
164 			goto state2;
165 		else if (state == 3)
166 			goto state3;
167 		else
168 			goto state4;
169 	}
170 	handler = &jmploc;
171 #ifdef DEBUG
172 	opentrace();
173 	trputs("Shell args:  ");  trargs(argv);
174 #endif
175 	rootpid = getpid();
176 	rootshell = 1;
177 	init();
178 	setstackmark(&smark);
179 	procargs(argc, argv);
180 	if (argv[0] && argv[0][0] == '-') {
181 		state = 1;
182 		read_profile("/etc/profile");
183 state1:
184 		state = 2;
185 		read_profile(".profile");
186 	}
187 state2:
188 	state = 3;
189 	if (getuid() == geteuid() && getgid() == getegid()) {
190 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
191 			state = 3;
192 			read_profile(shinit);
193 		}
194 	}
195 state3:
196 	state = 4;
197 	if (sflag == 0 || minusc) {
198 		static int sigs[] =  {
199 		    SIGINT, SIGQUIT, SIGHUP,
200 #ifdef SIGTSTP
201 		    SIGTSTP,
202 #endif
203 		    SIGPIPE
204 		};
205 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
206 		int i;
207 
208 		for (i = 0; i < SIGSSIZE; i++)
209 		    setsignal(sigs[i], 0);
210 	}
211 
212 	if (minusc)
213 		evalstring(minusc, 0);
214 
215 	if (sflag || minusc == NULL) {
216 state4:	/* XXX ??? - why isn't this before the "if" statement */
217 		cmdloop(1);
218 	}
219 #if PROFILE
220 	monitor(0);
221 #endif
222 	exitshell(exitstatus);
223 	/* NOTREACHED */
224 }
225 
226 
227 /*
228  * Read and execute commands.  "Top" is nonzero for the top level command
229  * loop; it turns on prompting if the shell is interactive.
230  */
231 
232 void
233 cmdloop(int top)
234 {
235 	union node *n;
236 	struct stackmark smark;
237 	int inter;
238 	int numeof = 0;
239 
240 	TRACE(("cmdloop(%d) called\n", top));
241 	setstackmark(&smark);
242 	for (;;) {
243 		if (pendingsigs)
244 			dotrap();
245 		inter = 0;
246 		if (iflag && top) {
247 			inter = 1;
248 			showjobs(out2, SHOW_CHANGED);
249 			chkmail(0);
250 			flushout(&errout);
251 		}
252 		n = parsecmd(inter);
253 		/* showtree(n); DEBUG */
254 		if (n == NEOF) {
255 			if (!top || numeof >= 50)
256 				break;
257 			if (!stoppedjobs()) {
258 				if (!Iflag)
259 					break;
260 				out2str("\nUse \"exit\" to leave shell.\n");
261 			}
262 			numeof++;
263 		} else if (n != NULL && nflag == 0) {
264 			job_warning = (job_warning == 2) ? 1 : 0;
265 			numeof = 0;
266 			evaltree(n, 0);
267 		}
268 		popstackmark(&smark);
269 		setstackmark(&smark);
270 		if (evalskip == SKIPFILE) {
271 			evalskip = 0;
272 			break;
273 		}
274 	}
275 	popstackmark(&smark);
276 }
277 
278 
279 
280 /*
281  * Read /etc/profile or .profile.  Return on error.
282  */
283 
284 STATIC void
285 read_profile(const char *name)
286 {
287 	int fd;
288 	int xflag_set = 0;
289 	int vflag_set = 0;
290 
291 	INTOFF;
292 	if ((fd = open(name, O_RDONLY)) >= 0)
293 		setinputfd(fd, 1);
294 	INTON;
295 	if (fd < 0)
296 		return;
297 	/* -q turns off -x and -v just when executing init files */
298 	if (qflag)  {
299 	    if (xflag)
300 		    xflag = 0, xflag_set = 1;
301 	    if (vflag)
302 		    vflag = 0, vflag_set = 1;
303 	}
304 	cmdloop(0);
305 	if (qflag)  {
306 	    if (xflag_set)
307 		    xflag = 1;
308 	    if (vflag_set)
309 		    vflag = 1;
310 	}
311 	popfile();
312 }
313 
314 
315 
316 /*
317  * Read a file containing shell functions.
318  */
319 
320 void
321 readcmdfile(char *name)
322 {
323 	int fd;
324 
325 	INTOFF;
326 	if ((fd = open(name, O_RDONLY)) >= 0)
327 		setinputfd(fd, 1);
328 	else
329 		error("Can't open %s", name);
330 	INTON;
331 	cmdloop(0);
332 	popfile();
333 }
334 
335 
336 
337 /*
338  * Take commands from a file.  To be compatible we should do a path
339  * search for the file, which is necessary to find sub-commands.
340  */
341 
342 
343 STATIC char *
344 find_dot_file(char *basename)
345 {
346 	char *fullname;
347 	const char *path = pathval();
348 	struct stat statb;
349 
350 	/* don't try this for absolute or relative paths */
351 	if (strchr(basename, '/'))
352 		return basename;
353 
354 	while ((fullname = padvance(&path, basename)) != NULL) {
355 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
356 			/*
357 			 * Don't bother freeing here, since it will
358 			 * be freed by the caller.
359 			 */
360 			return fullname;
361 		}
362 		stunalloc(fullname);
363 	}
364 
365 	/* not found in the PATH */
366 	error("%s: not found", basename);
367 	/* NOTREACHED */
368 }
369 
370 int
371 dotcmd(int argc, char **argv)
372 {
373 	exitstatus = 0;
374 
375 	if (argc >= 2) {		/* That's what SVR2 does */
376 		char *fullname;
377 		struct stackmark smark;
378 
379 		setstackmark(&smark);
380 		fullname = find_dot_file(argv[1]);
381 		setinputfile(fullname, 1);
382 		commandname = fullname;
383 		cmdloop(0);
384 		popfile();
385 		popstackmark(&smark);
386 	}
387 	return exitstatus;
388 }
389 
390 
391 int
392 exitcmd(int argc, char **argv)
393 {
394 	if (stoppedjobs())
395 		return 0;
396 	if (argc > 1)
397 		exitstatus = number(argv[1]);
398 	exitshell(exitstatus);
399 	/* NOTREACHED */
400 }
401