1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 <stdio.h>
36#include <signal.h>
37#include <sys/stat.h>
38#include <unistd.h>
39#include <fcntl.h>
40#include <locale.h>
41#include <errno.h>
42
43#include "shell.h"
44#include "main.h"
45#include "mail.h"
46#include "options.h"
47#include "output.h"
48#include "parser.h"
49#include "nodes.h"
50#include "expand.h"
51#include "eval.h"
52#include "jobs.h"
53#include "input.h"
54#include "trap.h"
55#include "var.h"
56#include "show.h"
57#include "memalloc.h"
58#include "error.h"
59#include "mystring.h"
60#include "exec.h"
61#include "cd.h"
62#include "redir.h"
63#include "builtins.h"
64#ifndef NO_HISTORY
65#include "myhistedit.h"
66#endif
67
68int rootpid;
69int rootshell;
70struct jmploc main_handler;
71int localeisutf8, initial_localeisutf8;
72
73static void reset(void);
74static void cmdloop(int);
75static void read_profile(const char *);
76static char *find_dot_file(char *);
77
78/*
79 * Main routine.  We initialize things, parse the arguments, execute
80 * profiles if we're a login shell, and then call cmdloop to execute
81 * commands.  The setjmp call sets up the location to jump to when an
82 * exception occurs.  When an exception occurs the variable "state"
83 * is used to figure out how far we had gotten.
84 */
85
86int
87main(int argc, char *argv[])
88{
89	/*
90	 * As smark is accessed after a longjmp, it cannot be a local in main().
91	 * The C standard specifies that the values of non-volatile local
92	 * variables are unspecified after a jump if modified between the
93	 * setjmp and longjmp.
94	 */
95	static struct stackmark smark, smark2;
96	volatile int state;
97	char *shinit;
98
99	(void) setlocale(LC_ALL, "");
100	initcharset();
101	state = 0;
102	if (setjmp(main_handler.loc)) {
103		if (state == 0 || iflag == 0 || ! rootshell ||
104		    exception == EXEXIT)
105			exitshell(exitstatus);
106		reset();
107		if (exception == EXINT)
108			out2fmt_flush("\n");
109		popstackmark(&smark);
110		FORCEINTON;				/* enable interrupts */
111		if (state == 1)
112			goto state1;
113		else if (state == 2)
114			goto state2;
115		else if (state == 3)
116			goto state3;
117		else
118			goto state4;
119	}
120	handler = &main_handler;
121#ifdef DEBUG
122	opentrace();
123	trputs("Shell args:  ");  trargs(argv);
124#endif
125	rootpid = getpid();
126	rootshell = 1;
127	INTOFF;
128	initvar();
129	setstackmark(&smark);
130	setstackmark(&smark2);
131	procargs(argc, argv);
132	trap_init();
133	pwd_init(iflag);
134	INTON;
135	if (iflag)
136		chkmail(1);
137	if (argv[0] && argv[0][0] == '-') {
138		state = 1;
139		read_profile("/etc/profile");
140state1:
141		state = 2;
142		if (privileged == 0)
143			read_profile("${HOME-}/.profile");
144		else
145			read_profile("/etc/suid_profile");
146	}
147state2:
148	state = 3;
149	if (!privileged && iflag) {
150		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
151			state = 3;
152			read_profile(shinit);
153		}
154	}
155#ifndef NO_HISTORY
156	if (iflag)
157		histload();
158#endif
159state3:
160	state = 4;
161	popstackmark(&smark2);
162	if (minusc) {
163		evalstring(minusc, sflag ? 0 : EV_EXIT);
164	}
165state4:
166	if (sflag || minusc == NULL) {
167		cmdloop(1);
168	}
169	exitshell(exitstatus);
170	/*NOTREACHED*/
171	return 0;
172}
173
174static void
175reset(void)
176{
177	reseteval();
178	resetinput();
179}
180
181/*
182 * Read and execute commands.  "Top" is nonzero for the top level command
183 * loop; it turns on prompting if the shell is interactive.
184 */
185
186static void
187cmdloop(int top)
188{
189	union node *n;
190	struct stackmark smark;
191	int inter;
192	int numeof = 0;
193
194	TRACE(("cmdloop(%d) called\n", top));
195	setstackmark(&smark);
196	for (;;) {
197		if (pendingsig)
198			dotrap();
199		inter = 0;
200		if (iflag && top) {
201			inter++;
202			showjobs(1, SHOWJOBS_DEFAULT);
203			chkmail(0);
204			flushout(&output);
205		}
206		n = parsecmd(inter);
207		/* showtree(n); DEBUG */
208		if (n == NEOF) {
209			if (!top || numeof >= 50)
210				break;
211			if (!stoppedjobs()) {
212				if (!Iflag)
213					break;
214				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
215			}
216			numeof++;
217		} else if (n != NULL && nflag == 0) {
218			job_warning = (job_warning == 2) ? 1 : 0;
219			numeof = 0;
220			evaltree(n, 0);
221		}
222		popstackmark(&smark);
223		setstackmark(&smark);
224		if (evalskip != 0) {
225			if (evalskip == SKIPRETURN)
226				evalskip = 0;
227			break;
228		}
229	}
230	popstackmark(&smark);
231	if (top && iflag) {
232		out2c('\n');
233		flushout(out2);
234	}
235}
236
237
238
239/*
240 * Read /etc/profile or .profile.  Return on error.
241 */
242
243static void
244read_profile(const char *name)
245{
246	int fd;
247	const char *expandedname;
248	int oflags = O_RDONLY | O_CLOEXEC;
249
250	if (verifyflag)
251		oflags |= O_VERIFY;
252
253	expandedname = expandstr(name);
254	if (expandedname == NULL)
255		return;
256	INTOFF;
257	if ((fd = open(expandedname, oflags)) >= 0)
258		setinputfd(fd, 1);
259	INTON;
260	if (fd < 0)
261		return;
262	cmdloop(0);
263	popfile();
264}
265
266
267
268/*
269 * Read a file containing shell functions.
270 */
271
272void
273readcmdfile(const char *name, int verify)
274{
275	setinputfile(name, 1, verify);
276	cmdloop(0);
277	popfile();
278}
279
280
281
282/*
283 * Take commands from a file.  To be compatible we should do a path
284 * search for the file, which is necessary to find sub-commands.
285 */
286
287
288static char *
289find_dot_file(char *basename)
290{
291	char *fullname;
292	const char *opt;
293	const char *path = pathval();
294	struct stat statb;
295
296	/* don't try this for absolute or relative paths */
297	if( strchr(basename, '/'))
298		return basename;
299
300	while ((fullname = padvance(&path, &opt, basename)) != NULL) {
301		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
302			/*
303			 * Don't bother freeing here, since it will
304			 * be freed by the caller.
305			 */
306			return fullname;
307		}
308		stunalloc(fullname);
309	}
310	return basename;
311}
312
313int
314dotcmd(int argc, char **argv)
315{
316	char *filename, *fullname;
317
318	if (argc < 2)
319		error("missing filename");
320
321	exitstatus = 0;
322
323	/*
324	 * Because we have historically not supported any options,
325	 * only treat "--" specially.
326	 */
327	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
328
329	fullname = find_dot_file(filename);
330	setinputfile(fullname, 1, -1 /* verify */);
331	commandname = fullname;
332	cmdloop(0);
333	popfile();
334	return exitstatus;
335}
336
337
338int
339exitcmd(int argc, char **argv)
340{
341	if (stoppedjobs())
342		return 0;
343	if (argc > 1)
344		exitshell(number(argv[1]));
345	else
346		exitshell_savedstatus();
347}
348