xref: /netbsd-src/bin/sh/main.c (revision 811e6386f8c5e4a3521c7003da29ec8673e344fa)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * 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. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 char copyright[] =
39 "@(#) Copyright (c) 1991 The Regents of the University of California.\n\
40  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 static char sccsid[] = "@(#)main.c	5.2 (Berkeley) 3/13/91";
45 static char rcsid[] = "$Header: /cvsroot/src/bin/sh/main.c,v 1.3 1993/03/23 00:28:22 cgd Exp $";
46 #endif /* not lint */
47 
48 #include <signal.h>
49 #include <fcntl.h>
50 #include "shell.h"
51 #include "main.h"
52 #include "mail.h"
53 #include "options.h"
54 #include "output.h"
55 #include "parser.h"
56 #include "nodes.h"
57 #include "eval.h"
58 #include "jobs.h"
59 #include "input.h"
60 #include "trap.h"
61 #if ATTY
62 #include "var.h"
63 #endif
64 #include "memalloc.h"
65 #include "error.h"
66 #include "init.h"
67 #include "mystring.h"
68 
69 #define PROFILE 0
70 
71 int rootpid;
72 int rootshell;
73 STATIC union node *curcmd;
74 STATIC union node *prevcmd;
75 extern int errno;
76 #if PROFILE
77 short profile_buf[16384];
78 extern int etext();
79 #endif
80 
81 #ifdef __STDC__
82 STATIC void read_profile(char *);
83 char *getenv(char *);
84 #else
85 STATIC void read_profile();
86 char *getenv();
87 #endif
88 
89 
90 /*
91  * Main routine.  We initialize things, parse the arguments, execute
92  * profiles if we're a login shell, and then call cmdloop to execute
93  * commands.  The setjmp call sets up the location to jump to when an
94  * exception occurs.  When an exception occurs the variable "state"
95  * is used to figure out how far we had gotten.
96  */
97 
98 main(argc, argv)  char **argv; {
99 	struct jmploc jmploc;
100 	struct stackmark smark;
101 	volatile int state;
102 	char *shinit;
103 
104 #if PROFILE
105 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
106 #endif
107 	state = 0;
108 	if (setjmp(jmploc.loc)) {
109 		/*
110 		 * When a shell procedure is executed, we raise the
111 		 * exception EXSHELLPROC to clean up before executing
112 		 * the shell procedure.
113 		 */
114 		if (exception == EXSHELLPROC) {
115 			rootpid = getpid();
116 			rootshell = 1;
117 			minusc = NULL;
118 			state = 3;
119 		} else if (state == 0 || iflag == 0 || ! rootshell)
120 			exitshell(2);
121 		reset();
122 #if ATTY
123 		if (exception == EXINT
124 		 && (! attyset() || equal(termval(), "emacs"))) {
125 #else
126 		if (exception == EXINT) {
127 #endif
128 			out2c('\n');
129 			flushout(&errout);
130 		}
131 		popstackmark(&smark);
132 		FORCEINTON;				/* enable interrupts */
133 		if (state == 1)
134 			goto state1;
135 		else if (state == 2)
136 			goto state2;
137 		else
138 			goto state3;
139 	}
140 	handler = &jmploc;
141 #ifdef DEBUG
142 	opentrace();
143 	trputs("Shell args:  ");  trargs(argv);
144 #endif
145 	rootpid = getpid();
146 	rootshell = 1;
147 	init();
148 	setstackmark(&smark);
149 	procargs(argc, argv);
150 	if (argv[0] && argv[0][0] == '-') {
151 		state = 1;
152 		read_profile("/etc/profile");
153 state1:
154 		state = 2;
155 		read_profile(".profile");
156 	} else if ((sflag || minusc) && (shinit = getenv("SHINIT")) != NULL) {
157 		state = 2;
158 		evalstring(shinit);
159 	}
160 state2:
161 	state = 3;
162 	if (minusc) {
163 		evalstring(minusc);
164 	}
165 	if (sflag || minusc == NULL) {
166 state3:
167 		cmdloop(1);
168 	}
169 #if PROFILE
170 	monitor(0);
171 #endif
172 	exitshell(exitstatus);
173 }
174 
175 
176 /*
177  * Read and execute commands.  "Top" is nonzero for the top level command
178  * loop; it turns on prompting if the shell is interactive.
179  */
180 
181 void
182 cmdloop(top) {
183 	union node *n;
184 	struct stackmark smark;
185 	int inter;
186 	int numeof;
187 
188 	TRACE(("cmdloop(%d) called\n", top));
189 	setstackmark(&smark);
190 	numeof = 0;
191 	for (;;) {
192 		if (pendingsigs)
193 			dotrap();
194 		inter = 0;
195 		if (iflag && top) {
196 			inter++;
197 			showjobs(1);
198 			chkmail(0);
199 			flushout(&output);
200 		}
201 		n = parsecmd(inter);
202 #ifdef DEBUG
203 		/* showtree(n); */
204 #endif
205 		if (n == NEOF) {
206 			if (Iflag == 0 || numeof >= 50)
207 				break;
208 			out2str("\nUse \"exit\" to leave shell.\n");
209 			numeof++;
210 		} else if (n != NULL && nflag == 0) {
211 			if (inter) {
212 				INTOFF;
213 				if (prevcmd)
214 					freefunc(prevcmd);
215 				prevcmd = curcmd;
216 				curcmd = copyfunc(n);
217 				INTON;
218 			}
219 			evaltree(n, 0);
220 #ifdef notdef
221 			if (exitstatus)				      /*DEBUG*/
222 				outfmt(&errout, "Exit status 0x%X\n", exitstatus);
223 #endif
224 		}
225 		popstackmark(&smark);
226 	}
227 	popstackmark(&smark);		/* unnecessary */
228 }
229 
230 
231 
232 /*
233  * Read /etc/profile or .profile.  Return on error.
234  */
235 
236 STATIC void
237 read_profile(name)
238 	char *name;
239 	{
240 	int fd;
241 
242 	INTOFF;
243 	if ((fd = open(name, O_RDONLY)) >= 0)
244 		setinputfd(fd, 1);
245 	INTON;
246 	if (fd < 0)
247 		return;
248 	cmdloop(0);
249 	popfile();
250 }
251 
252 
253 
254 /*
255  * Read a file containing shell functions.
256  */
257 
258 void
259 readcmdfile(name)
260 	char *name;
261 	{
262 	int fd;
263 
264 	INTOFF;
265 	if ((fd = open(name, O_RDONLY)) >= 0)
266 		setinputfd(fd, 1);
267 	else
268 		error("Can't open %s", name);
269 	INTON;
270 	cmdloop(0);
271 	popfile();
272 }
273 
274 
275 
276 /*
277  * Take commands from a file.  To be compatable we should do a path
278  * search for the file, but a path search doesn't make any sense.
279  */
280 
281 dotcmd(argc, argv)  char **argv; {
282 	exitstatus = 0;
283 	if (argc >= 2) {		/* That's what SVR2 does */
284 		setinputfile(argv[1], 1);
285 		commandname = argv[1];
286 		cmdloop(0);
287 		popfile();
288 	}
289 	return exitstatus;
290 }
291 
292 
293 exitcmd(argc, argv)  char **argv; {
294 	if (argc > 1)
295 		exitstatus = number(argv[1]);
296 	exitshell(exitstatus);
297 }
298 
299 
300 lccmd(argc, argv)  char **argv; {
301 	if (argc > 1) {
302 		defun(argv[1], prevcmd);
303 		return 0;
304 	} else {
305 		INTOFF;
306 		freefunc(curcmd);
307 		curcmd = prevcmd;
308 		prevcmd = NULL;
309 		INTON;
310 		evaltree(curcmd, 0);
311 		return exitstatus;
312 	}
313 }
314 
315 
316 
317 #ifdef notdef
318 /*
319  * Should never be called.
320  */
321 
322 void
323 exit(exitstatus) {
324 	_exit(exitstatus);
325 }
326 #endif
327