xref: /netbsd-src/bin/sh/main.c (revision bada23909e740596d0a3785a73bd3583a9807fb8)
1 /*	$NetBSD: main.c,v 1.32 1999/02/05 21:21:27 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 1.32 1999/02/05 21:21:27 christos Exp $");
50 #endif
51 #endif /* not lint */
52 
53 #include <stdio.h>
54 #include <signal.h>
55 #include <sys/stat.h>
56 #include <unistd.h>
57 #include <fcntl.h>
58 
59 
60 #include "shell.h"
61 #include "main.h"
62 #include "mail.h"
63 #include "options.h"
64 #include "output.h"
65 #include "parser.h"
66 #include "nodes.h"
67 #include "expand.h"
68 #include "eval.h"
69 #include "jobs.h"
70 #include "input.h"
71 #include "trap.h"
72 #include "var.h"
73 #include "show.h"
74 #include "memalloc.h"
75 #include "error.h"
76 #include "init.h"
77 #include "mystring.h"
78 #include "exec.h"
79 #include "cd.h"
80 
81 #define PROFILE 0
82 
83 int rootpid;
84 int rootshell;
85 STATIC union node *curcmd;
86 STATIC union node *prevcmd;
87 extern int errno;
88 #if PROFILE
89 short profile_buf[16384];
90 extern int etext();
91 #endif
92 
93 STATIC void read_profile __P((char *));
94 STATIC char *find_dot_file __P((char *));
95 int main __P((int, char **));
96 
97 /*
98  * Main routine.  We initialize things, parse the arguments, execute
99  * profiles if we're a login shell, and then call cmdloop to execute
100  * commands.  The setjmp call sets up the location to jump to when an
101  * exception occurs.  When an exception occurs the variable "state"
102  * is used to figure out how far we had gotten.
103  */
104 
105 int
106 main(argc, argv)
107 	int argc;
108 	char **argv;
109 {
110 	struct jmploc jmploc;
111 	struct stackmark smark;
112 	volatile int state;
113 	char *shinit;
114 
115 #if PROFILE
116 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
117 #endif
118 	state = 0;
119 	if (setjmp(jmploc.loc)) {
120 		/*
121 		 * When a shell procedure is executed, we raise the
122 		 * exception EXSHELLPROC to clean up before executing
123 		 * the shell procedure.
124 		 */
125 		switch (exception) {
126 		case EXSHELLPROC:
127 			rootpid = getpid();
128 			rootshell = 1;
129 			minusc = NULL;
130 			state = 3;
131 			break;
132 
133 		case EXEXEC:
134 			exitstatus = exerrno;
135 			break;
136 
137 		case EXERROR:
138 			exitstatus = 2;
139 			break;
140 
141 		default:
142 			break;
143 		}
144 
145 		if (exception != EXSHELLPROC) {
146 		    if (state == 0 || iflag == 0 || ! rootshell)
147 			    exitshell(exitstatus);
148 		}
149 		reset();
150 		if (exception == EXINT
151 #if ATTY
152 		 && (! attyset() || equal(termval(), "emacs"))
153 #endif
154 		 ) {
155 			out2c('\n');
156 			flushout(&errout);
157 		}
158 		popstackmark(&smark);
159 		FORCEINTON;				/* enable interrupts */
160 		if (state == 1)
161 			goto state1;
162 		else if (state == 2)
163 			goto state2;
164 		else if (state == 3)
165 			goto state3;
166 		else
167 			goto state4;
168 	}
169 	handler = &jmploc;
170 #ifdef DEBUG
171 	opentrace();
172 	trputs("Shell args:  ");  trargs(argv);
173 #endif
174 	rootpid = getpid();
175 	rootshell = 1;
176 	init();
177 	setstackmark(&smark);
178 	procargs(argc, argv);
179 	if (argv[0] && argv[0][0] == '-') {
180 		state = 1;
181 		read_profile("/etc/profile");
182 state1:
183 		state = 2;
184 		read_profile(".profile");
185 	}
186 state2:
187 	state = 3;
188 	if (getuid() == geteuid() && getgid() == getegid()) {
189 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
190 			state = 3;
191 			read_profile(shinit);
192 		}
193 	}
194 state3:
195 	state = 4;
196 	if (minusc) {
197 		static int sigs[] =  {
198 		    SIGINT, SIGQUIT, SIGHUP,
199 #ifdef SIGTSTP
200 		    SIGTSTP,
201 #endif
202 		    SIGPIPE
203 		};
204 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
205 		int i;
206 
207 		for (i = 0; i < SIGSSIZE; i++)
208 		    setsignal(sigs[i]);
209 		evalstring(minusc);
210 	}
211 	if (sflag || minusc == NULL) {
212 state4:	/* XXX ??? - why isn't this before the "if" statement */
213 		cmdloop(1);
214 	}
215 #if PROFILE
216 	monitor(0);
217 #endif
218 	exitshell(exitstatus);
219 	/* NOTREACHED */
220 }
221 
222 
223 /*
224  * Read and execute commands.  "Top" is nonzero for the top level command
225  * loop; it turns on prompting if the shell is interactive.
226  */
227 
228 void
229 cmdloop(top)
230 	int top;
231 {
232 	union node *n;
233 	struct stackmark smark;
234 	int inter;
235 	int numeof = 0;
236 
237 	TRACE(("cmdloop(%d) called\n", top));
238 	setstackmark(&smark);
239 	for (;;) {
240 		if (pendingsigs)
241 			dotrap();
242 		inter = 0;
243 		if (iflag && top) {
244 			inter++;
245 			showjobs(1);
246 			chkmail(0);
247 			flushout(&output);
248 		}
249 		n = parsecmd(inter);
250 		/* showtree(n); DEBUG */
251 		if (n == NEOF) {
252 			if (!top || numeof >= 50)
253 				break;
254 			if (!stoppedjobs()) {
255 				if (!Iflag)
256 					break;
257 				out2str("\nUse \"exit\" to leave shell.\n");
258 			}
259 			numeof++;
260 		} else if (n != NULL && nflag == 0) {
261 			job_warning = (job_warning == 2) ? 1 : 0;
262 			numeof = 0;
263 			evaltree(n, 0);
264 		}
265 		popstackmark(&smark);
266 		if (evalskip == SKIPFILE) {
267 			evalskip = 0;
268 			break;
269 		}
270 	}
271 	popstackmark(&smark);		/* unnecessary */
272 }
273 
274 
275 
276 /*
277  * Read /etc/profile or .profile.  Return on error.
278  */
279 
280 STATIC void
281 read_profile(name)
282 	char *name;
283 {
284 	int fd;
285 	int xflag_set = 0;
286 	int vflag_set = 0;
287 
288 	INTOFF;
289 	if ((fd = open(name, O_RDONLY)) >= 0)
290 		setinputfd(fd, 1);
291 	INTON;
292 	if (fd < 0)
293 		return;
294 	/* -q turns off -x and -v just when executing init files */
295 	if (qflag)  {
296 	    if (xflag)
297 		    xflag = 0, xflag_set = 1;
298 	    if (vflag)
299 		    vflag = 0, vflag_set = 1;
300 	}
301 	cmdloop(0);
302 	if (qflag)  {
303 	    if (xflag_set)
304 		    xflag = 1;
305 	    if (vflag_set)
306 		    vflag = 1;
307 	}
308 	popfile();
309 }
310 
311 
312 
313 /*
314  * Read a file containing shell functions.
315  */
316 
317 void
318 readcmdfile(name)
319 	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 compatable 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(basename)
343 	char *basename;
344 {
345 	char *fullname;
346 	char *path = pathval();
347 	struct stat statb;
348 
349 	/* don't try this for absolute or relative paths */
350 	if (strchr(basename, '/'))
351 		return basename;
352 
353 	while ((fullname = padvance(&path, basename)) != NULL) {
354 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
355 			/*
356 			 * Don't bother freeing here, since it will
357 			 * be freed by the caller.
358 			 */
359 			return fullname;
360 		}
361 		stunalloc(fullname);
362 	}
363 
364 	/* not found in the PATH */
365 	error("%s: not found", basename);
366 	/* NOTREACHED */
367 }
368 
369 int
370 dotcmd(argc, argv)
371 	int argc;
372 	char **argv;
373 {
374 	struct strlist *sp;
375 	exitstatus = 0;
376 
377 	for (sp = cmdenviron; sp ; sp = sp->next)
378 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
379 
380 	if (argc >= 2) {		/* That's what SVR2 does */
381 		char *fullname;
382 		struct stackmark smark;
383 
384 		setstackmark(&smark);
385 		fullname = find_dot_file(argv[1]);
386 		setinputfile(fullname, 1);
387 		commandname = fullname;
388 		cmdloop(0);
389 		popfile();
390 		popstackmark(&smark);
391 	}
392 	return exitstatus;
393 }
394 
395 
396 int
397 exitcmd(argc, argv)
398 	int argc;
399 	char **argv;
400 {
401 	extern int oexitstatus;
402 
403 	if (stoppedjobs())
404 		return 0;
405 	if (argc > 1)
406 		exitstatus = number(argv[1]);
407 	else
408 		exitstatus = oexitstatus;
409 	exitshell(exitstatus);
410 	/* NOTREACHED */
411 }
412