xref: /dragonfly/bin/sh/main.c (revision eca362d0)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Kenneth Almquist.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)main.c	8.6 (Berkeley) 5/28/95";
36 #endif
37 #endif /* not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <stdio.h>
42 #include <signal.h>
43 #include <sys/stat.h>
44 #include <unistd.h>
45 #include <fcntl.h>
46 #include <locale.h>
47 #include <errno.h>
48 
49 #include "shell.h"
50 #include "main.h"
51 #include "mail.h"
52 #include "options.h"
53 #include "output.h"
54 #include "parser.h"
55 #include "nodes.h"
56 #include "expand.h"
57 #include "eval.h"
58 #include "jobs.h"
59 #include "input.h"
60 #include "trap.h"
61 #include "var.h"
62 #include "show.h"
63 #include "memalloc.h"
64 #include "error.h"
65 #include "mystring.h"
66 #include "exec.h"
67 #include "cd.h"
68 #include "redir.h"
69 #include "builtins.h"
70 
71 int rootpid;
72 int rootshell;
73 struct jmploc main_handler;
74 int localeisutf8, initial_localeisutf8;
75 
76 static void reset(void);
77 static void cmdloop(int);
78 static void read_profile(const char *);
79 static char *find_dot_file(char *);
80 
81 /*
82  * Main routine.  We initialize things, parse the arguments, execute
83  * profiles if we're a login shell, and then call cmdloop to execute
84  * commands.  The setjmp call sets up the location to jump to when an
85  * exception occurs.  When an exception occurs the variable "state"
86  * is used to figure out how far we had gotten.
87  */
88 
89 int
90 main(int argc, char *argv[])
91 {
92 	struct stackmark smark, smark2;
93 	volatile int state;
94 	char *shinit;
95 
96 	(void) setlocale(LC_ALL, "");
97 	initcharset();
98 	state = 0;
99 	if (setjmp(main_handler.loc)) {
100 		switch (exception) {
101 		case EXEXEC:
102 			exitstatus = exerrno;
103 			break;
104 
105 		case EXERROR:
106 			exitstatus = 2;
107 			break;
108 
109 		default:
110 			break;
111 		}
112 
113 		if (state == 0 || iflag == 0 || ! rootshell ||
114 		    exception == EXEXIT)
115 			exitshell(exitstatus);
116 		reset();
117 		if (exception == EXINT)
118 			out2fmt_flush("\n");
119 		popstackmark(&smark);
120 		FORCEINTON;				/* enable interrupts */
121 		if (state == 1)
122 			goto state1;
123 		else if (state == 2)
124 			goto state2;
125 		else if (state == 3)
126 			goto state3;
127 		else
128 			goto state4;
129 	}
130 	handler = &main_handler;
131 #ifdef DEBUG
132 	opentrace();
133 	trputs("Shell args:  ");  trargs(argv);
134 #endif
135 	rootpid = getpid();
136 	rootshell = 1;
137 	INTOFF;
138 	initvar();
139 	setstackmark(&smark);
140 	setstackmark(&smark2);
141 	procargs(argc, argv);
142 	pwd_init(iflag);
143 	INTON;
144 	if (iflag)
145 		chkmail(1);
146 	if (argv[0] && argv[0][0] == '-') {
147 		state = 1;
148 		read_profile("/etc/profile");
149 state1:
150 		state = 2;
151 		if (privileged == 0)
152 			read_profile("${HOME-}/.profile");
153 		else
154 			read_profile("/etc/suid_profile");
155 	}
156 state2:
157 	state = 3;
158 	if (!privileged && iflag) {
159 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
160 			state = 3;
161 			read_profile(shinit);
162 		}
163 	}
164 state3:
165 	state = 4;
166 	popstackmark(&smark2);
167 	if (minusc) {
168 		evalstring(minusc, sflag ? 0 : EV_EXIT);
169 	}
170 state4:
171 	if (sflag || minusc == NULL) {
172 		cmdloop(1);
173 	}
174 	exitshell(exitstatus);
175 	/*NOTREACHED*/
176 	return 0;
177 }
178 
179 static void
180 reset(void)
181 {
182 	reseteval();
183 	resetinput();
184 }
185 
186 /*
187  * Read and execute commands.  "Top" is nonzero for the top level command
188  * loop; it turns on prompting if the shell is interactive.
189  */
190 
191 static void
192 cmdloop(int top)
193 {
194 	union node *n;
195 	struct stackmark smark;
196 	int inter;
197 	int numeof = 0;
198 
199 	TRACE(("cmdloop(%d) called\n", top));
200 	setstackmark(&smark);
201 	for (;;) {
202 		if (pendingsig)
203 			dotrap();
204 		inter = 0;
205 		if (iflag && top) {
206 			inter++;
207 			showjobs(1, SHOWJOBS_DEFAULT);
208 			chkmail(0);
209 			flushout(&output);
210 		}
211 		n = parsecmd(inter);
212 		/* showtree(n); DEBUG */
213 		if (n == NEOF) {
214 			if (!top || numeof >= 50)
215 				break;
216 			if (!stoppedjobs()) {
217 				if (!Iflag)
218 					break;
219 				out2fmt_flush("\nUse \"exit\" to leave shell.\n");
220 			}
221 			numeof++;
222 		} else if (n != NULL && nflag == 0) {
223 			job_warning = (job_warning == 2) ? 1 : 0;
224 			numeof = 0;
225 			evaltree(n, 0);
226 		}
227 		popstackmark(&smark);
228 		setstackmark(&smark);
229 		if (evalskip != 0) {
230 			if (evalskip == SKIPRETURN)
231 				evalskip = 0;
232 			break;
233 		}
234 	}
235 	popstackmark(&smark);
236 }
237 
238 
239 
240 /*
241  * Read /etc/profile or .profile.  Return on error.
242  */
243 
244 static void
245 read_profile(const char *name)
246 {
247 	int fd;
248 	const char *expandedname;
249 
250 	expandedname = expandstr(name);
251 	if (expandedname == NULL)
252 		return;
253 	INTOFF;
254 	if ((fd = open(expandedname, O_RDONLY | O_CLOEXEC_MAYBE)) >= 0)
255 		setinputfd(fd, 1);
256 	INTON;
257 	if (fd < 0)
258 		return;
259 	cmdloop(0);
260 	popfile();
261 }
262 
263 
264 
265 /*
266  * Read a file containing shell functions.
267  */
268 
269 void
270 readcmdfile(const char *name)
271 {
272 	setinputfile(name, 1);
273 	cmdloop(0);
274 	popfile();
275 }
276 
277 
278 
279 /*
280  * Take commands from a file.  To be compatible we should do a path
281  * search for the file, which is necessary to find sub-commands.
282  */
283 
284 
285 static char *
286 find_dot_file(char *basename)
287 {
288 	char *fullname;
289 	const char *path = pathval();
290 	struct stat statb;
291 
292 	/* don't try this for absolute or relative paths */
293 	if( strchr(basename, '/'))
294 		return basename;
295 
296 	while ((fullname = padvance(&path, basename)) != NULL) {
297 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
298 			/*
299 			 * Don't bother freeing here, since it will
300 			 * be freed by the caller.
301 			 */
302 			return fullname;
303 		}
304 		stunalloc(fullname);
305 	}
306 	return basename;
307 }
308 
309 int
310 dotcmd(int argc, char **argv)
311 {
312 	char *filename, *fullname;
313 
314 	if (argc < 2)
315 		error("missing filename");
316 
317 	exitstatus = 0;
318 
319 	/*
320 	 * Because we have historically not supported any options,
321 	 * only treat "--" specially.
322 	 */
323 	filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
324 
325 	fullname = find_dot_file(filename);
326 	setinputfile(fullname, 1);
327 	commandname = fullname;
328 	cmdloop(0);
329 	popfile();
330 	return exitstatus;
331 }
332 
333 
334 int
335 exitcmd(int argc, char **argv)
336 {
337 	if (stoppedjobs())
338 		return 0;
339 	if (argc > 1)
340 		exitshell(number(argv[1]));
341 	else
342 		exitshell_savedstatus();
343 }
344