1/*	$NetBSD: main.c,v 1.56 2010/02/21 09:54:57 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. 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
43static char sccsid[] = "@(#)main.c	8.7 (Berkeley) 7/19/95";
44#else
45__RCSID("$NetBSD: main.c,v 1.56 2010/02/21 09:54:57 christos 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 <stdlib.h>
55#include <locale.h>
56#include <fcntl.h>
57
58
59#include "shell.h"
60#include "main.h"
61#include "mail.h"
62#include "options.h"
63#include "builtins.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
83int rootpid;
84int rootshell;
85int posix;
86#if PROFILE
87short profile_buf[16384];
88extern int etext();
89#endif
90
91STATIC void read_profile(const char *);
92STATIC char *find_dot_file(char *);
93int main(int, char **);
94
95/*
96 * Main routine.  We initialize things, parse the arguments, execute
97 * profiles if we're a login shell, and then call cmdloop to execute
98 * commands.  The setjmp call sets up the location to jump to when an
99 * exception occurs.  When an exception occurs the variable "state"
100 * is used to figure out how far we had gotten.
101 */
102
103int
104main(int argc, char **argv)
105{
106	struct jmploc jmploc;
107	struct stackmark smark;
108	volatile int state;
109	char *shinit;
110
111	setlocale(LC_ALL, "");
112
113	posix = getenv("POSIXLY_CORRECT") != NULL;
114#if PROFILE
115	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
116#endif
117	state = 0;
118	if (setjmp(jmploc.loc)) {
119		/*
120		 * When a shell procedure is executed, we raise the
121		 * exception EXSHELLPROC to clean up before executing
122		 * the shell procedure.
123		 */
124		switch (exception) {
125		case EXSHELLPROC:
126			rootpid = getpid();
127			rootshell = 1;
128			minusc = NULL;
129			state = 3;
130			break;
131
132		case EXEXEC:
133			exitstatus = exerrno;
134			break;
135
136		case EXERROR:
137			exitstatus = 2;
138			break;
139
140		default:
141			break;
142		}
143
144		if (exception != EXSHELLPROC) {
145			if (state == 0 || iflag == 0 || ! rootshell)
146				exitshell(exitstatus);
147		}
148		reset();
149		if (exception == EXINT
150#if ATTY
151		 && (! attyset() || equal(termval(), "emacs"))
152#endif
153		 ) {
154			out2c('\n');
155			flushout(&errout);
156		}
157		popstackmark(&smark);
158		FORCEINTON;				/* enable interrupts */
159		if (state == 1)
160			goto state1;
161		else if (state == 2)
162			goto state2;
163		else if (state == 3)
164			goto state3;
165		else
166			goto state4;
167	}
168	handler = &jmploc;
169#ifdef DEBUG
170#if DEBUG == 2
171	debug = 1;
172#endif
173	opentrace();
174	trputs("Shell args:  ");  trargs(argv);
175#endif
176	rootpid = getpid();
177	rootshell = 1;
178	init();
179	initpwd();
180	setstackmark(&smark);
181	procargs(argc, argv);
182	if (argv[0] && argv[0][0] == '-') {
183		state = 1;
184		read_profile("/etc/profile");
185state1:
186		state = 2;
187		read_profile(".profile");
188	}
189state2:
190	state = 3;
191	if ((iflag || !posix) &&
192	    getuid() == geteuid() && getgid() == getegid()) {
193		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
194			state = 3;
195			read_profile(shinit);
196		}
197	}
198state3:
199	state = 4;
200	if (sflag == 0 || minusc) {
201		static int sigs[] =  {
202		    SIGINT, SIGQUIT, SIGHUP,
203#ifdef SIGTSTP
204		    SIGTSTP,
205#endif
206		    SIGPIPE
207		};
208#define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
209		size_t i;
210
211		for (i = 0; i < SIGSSIZE; i++)
212		    setsignal(sigs[i], 0);
213	}
214
215	if (minusc)
216		evalstring(minusc, 0);
217
218	if (sflag || minusc == NULL) {
219state4:	/* XXX ??? - why isn't this before the "if" statement */
220		cmdloop(1);
221	}
222#if PROFILE
223	monitor(0);
224#endif
225	exitshell(exitstatus);
226	/* NOTREACHED */
227}
228
229
230/*
231 * Read and execute commands.  "Top" is nonzero for the top level command
232 * loop; it turns on prompting if the shell is interactive.
233 */
234
235void
236cmdloop(int top)
237{
238	union node *n;
239	struct stackmark smark;
240	int inter;
241	int numeof = 0;
242
243	TRACE(("cmdloop(%d) called\n", top));
244	setstackmark(&smark);
245	for (;;) {
246		if (pendingsigs)
247			dotrap();
248		inter = 0;
249		if (iflag == 1 && top) {
250			inter = 1;
251			showjobs(out2, SHOW_CHANGED);
252			chkmail(0);
253			flushout(&errout);
254		}
255		n = parsecmd(inter);
256		/* showtree(n); DEBUG */
257		if (n == NEOF) {
258			if (!top || numeof >= 50)
259				break;
260			if (!stoppedjobs()) {
261				if (!Iflag)
262					break;
263				out2str("\nUse \"exit\" to leave shell.\n");
264			}
265			numeof++;
266		} else if (n != NULL && nflag == 0) {
267			job_warning = (job_warning == 2) ? 1 : 0;
268			numeof = 0;
269			evaltree(n, 0);
270		}
271		popstackmark(&smark);
272		setstackmark(&smark);
273		if (evalskip == SKIPFILE) {
274			evalskip = 0;
275			break;
276		}
277	}
278	popstackmark(&smark);
279}
280
281
282
283/*
284 * Read /etc/profile or .profile.  Return on error.
285 */
286
287STATIC void
288read_profile(const char *name)
289{
290	int fd;
291	int xflag_set = 0;
292	int vflag_set = 0;
293
294	INTOFF;
295	if ((fd = open(name, O_RDONLY)) >= 0)
296		setinputfd(fd, 1);
297	INTON;
298	if (fd < 0)
299		return;
300	/* -q turns off -x and -v just when executing init files */
301	if (qflag)  {
302	    if (xflag)
303		    xflag = 0, xflag_set = 1;
304	    if (vflag)
305		    vflag = 0, vflag_set = 1;
306	}
307	cmdloop(0);
308	if (qflag)  {
309	    if (xflag_set)
310		    xflag = 1;
311	    if (vflag_set)
312		    vflag = 1;
313	}
314	popfile();
315}
316
317
318
319/*
320 * Read a file containing shell functions.
321 */
322
323void
324readcmdfile(char *name)
325{
326	int fd;
327
328	INTOFF;
329	if ((fd = open(name, O_RDONLY)) >= 0)
330		setinputfd(fd, 1);
331	else
332		error("Can't open %s", name);
333	INTON;
334	cmdloop(0);
335	popfile();
336}
337
338
339
340/*
341 * Take commands from a file.  To be compatible we should do a path
342 * search for the file, which is necessary to find sub-commands.
343 */
344
345
346STATIC char *
347find_dot_file(char *basename)
348{
349	char *fullname;
350	const char *path = pathval();
351	struct stat statb;
352
353	/* don't try this for absolute or relative paths */
354	if (strchr(basename, '/'))
355		return basename;
356
357	while ((fullname = padvance(&path, basename)) != NULL) {
358		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
359			/*
360			 * Don't bother freeing here, since it will
361			 * be freed by the caller.
362			 */
363			return fullname;
364		}
365		stunalloc(fullname);
366	}
367
368	/* not found in the PATH */
369	error("%s: not found", basename);
370	/* NOTREACHED */
371}
372
373int
374dotcmd(int argc, char **argv)
375{
376	exitstatus = 0;
377
378	if (argc >= 2) {		/* That's what SVR2 does */
379		char *fullname;
380		struct stackmark smark;
381
382		setstackmark(&smark);
383		fullname = find_dot_file(argv[1]);
384		setinputfile(fullname, 1);
385		commandname = fullname;
386		cmdloop(0);
387		popfile();
388		popstackmark(&smark);
389	}
390	return exitstatus;
391}
392
393
394int
395exitcmd(int argc, char **argv)
396{
397	if (stoppedjobs())
398		return 0;
399	if (argc > 1)
400		exitstatus = number(argv[1]);
401	exitshell(exitstatus);
402	/* NOTREACHED */
403}
404