xref: /original-bsd/bin/sh/main.c (revision 454fcdce)
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  * %sccs.include.redist.c%
9  */
10 
11 #ifndef lint
12 char copyright[] =
13 "@(#) Copyright (c) 1991 The Regents of the University of California.\n\
14  All rights reserved.\n";
15 #endif /* not lint */
16 
17 #ifndef lint
18 static char sccsid[] = "@(#)main.c	5.1 (Berkeley) 03/07/91";
19 #endif /* not lint */
20 
21 #include <signal.h>
22 #include <fcntl.h>
23 #include "shell.h"
24 #include "main.h"
25 #include "mail.h"
26 #include "options.h"
27 #include "output.h"
28 #include "parser.h"
29 #include "nodes.h"
30 #include "eval.h"
31 #include "jobs.h"
32 #include "input.h"
33 #include "trap.h"
34 #if ATTY
35 #include "var.h"
36 #endif
37 #include "memalloc.h"
38 #include "error.h"
39 #include "init.h"
40 #include "mystring.h"
41 
42 #define PROFILE 0
43 
44 int rootpid;
45 int rootshell;
46 STATIC union node *curcmd;
47 STATIC union node *prevcmd;
48 extern int errno;
49 #if PROFILE
50 short profile_buf[16384];
51 extern int etext();
52 #endif
53 
54 #ifdef __STDC__
55 STATIC void read_profile(char *);
56 char *getenv(char *);
57 #else
58 STATIC void read_profile();
59 char *getenv();
60 #endif
61 
62 
63 /*
64  * Main routine.  We initialize things, parse the arguments, execute
65  * profiles if we're a login shell, and then call cmdloop to execute
66  * commands.  The setjmp call sets up the location to jump to when an
67  * exception occurs.  When an exception occurs the variable "state"
68  * is used to figure out how far we had gotten.
69  */
70 
71 main(argc, argv)  char **argv; {
72 	struct jmploc jmploc;
73 	struct stackmark smark;
74 	volatile int state;
75 	char *shinit;
76 
77 #if PROFILE
78 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
79 #endif
80 	state = 0;
81 	if (setjmp(jmploc.loc)) {
82 		/*
83 		 * When a shell procedure is executed, we raise the
84 		 * exception EXSHELLPROC to clean up before executing
85 		 * the shell procedure.
86 		 */
87 		if (exception == EXSHELLPROC) {
88 			rootpid = getpid();
89 			rootshell = 1;
90 			minusc = NULL;
91 			state = 3;
92 		} else if (state == 0 || iflag == 0 || ! rootshell)
93 			exitshell(2);
94 		reset();
95 #if ATTY
96 		if (exception == EXINT
97 		 && (! attyset() || equal(termval(), "emacs"))) {
98 #else
99 		if (exception == EXINT) {
100 #endif
101 			out2c('\n');
102 			flushout(&errout);
103 		}
104 		popstackmark(&smark);
105 		FORCEINTON;				/* enable interrupts */
106 		if (state == 1)
107 			goto state1;
108 		else if (state == 2)
109 			goto state2;
110 		else
111 			goto state3;
112 	}
113 	handler = &jmploc;
114 #ifdef DEBUG
115 	opentrace();
116 	trputs("Shell args:  ");  trargs(argv);
117 #endif
118 	rootpid = getpid();
119 	rootshell = 1;
120 	init();
121 	setstackmark(&smark);
122 	procargs(argc, argv);
123 	if (argv[0] && argv[0][0] == '-') {
124 		state = 1;
125 		read_profile("/etc/profile");
126 state1:
127 		state = 2;
128 		read_profile(".profile");
129 	} else if ((sflag || minusc) && (shinit = getenv("SHINIT")) != NULL) {
130 		state = 2;
131 		evalstring(shinit);
132 	}
133 state2:
134 	state = 3;
135 	if (minusc) {
136 		evalstring(minusc);
137 	}
138 	if (sflag || minusc == NULL) {
139 state3:
140 		cmdloop(1);
141 	}
142 #if PROFILE
143 	monitor(0);
144 #endif
145 	exitshell(exitstatus);
146 }
147 
148 
149 /*
150  * Read and execute commands.  "Top" is nonzero for the top level command
151  * loop; it turns on prompting if the shell is interactive.
152  */
153 
154 void
155 cmdloop(top) {
156 	union node *n;
157 	struct stackmark smark;
158 	int inter;
159 	int numeof;
160 
161 	TRACE(("cmdloop(%d) called\n", top));
162 	setstackmark(&smark);
163 	numeof = 0;
164 	for (;;) {
165 		if (pendingsigs)
166 			dotrap();
167 		inter = 0;
168 		if (iflag && top) {
169 			inter++;
170 			showjobs(1);
171 			chkmail(0);
172 			flushout(&output);
173 		}
174 		n = parsecmd(inter);
175 #ifdef DEBUG
176 		/* BROKEN - FIX showtree(n); */
177 #endif
178 		if (n == NEOF) {
179 			if (Iflag == 0 || numeof >= 50)
180 				break;
181 			out2str("\nUse \"exit\" to leave shell.\n");
182 			numeof++;
183 		} else if (n != NULL && nflag == 0) {
184 			if (inter) {
185 				INTOFF;
186 				if (prevcmd)
187 					freefunc(prevcmd);
188 				prevcmd = curcmd;
189 				curcmd = copyfunc(n);
190 				INTON;
191 			}
192 			evaltree(n, 0);
193 #ifdef notdef
194 			if (exitstatus)				      /*DEBUG*/
195 				outfmt(&errout, "Exit status 0x%X\n", exitstatus);
196 #endif
197 		}
198 		popstackmark(&smark);
199 	}
200 	popstackmark(&smark);		/* unnecessary */
201 }
202 
203 
204 
205 /*
206  * Read /etc/profile or .profile.  Return on error.
207  */
208 
209 STATIC void
210 read_profile(name)
211 	char *name;
212 	{
213 	int fd;
214 
215 	INTOFF;
216 	if ((fd = open(name, O_RDONLY)) >= 0)
217 		setinputfd(fd, 1);
218 	INTON;
219 	if (fd < 0)
220 		return;
221 	cmdloop(0);
222 	popfile();
223 }
224 
225 
226 
227 /*
228  * Read a file containing shell functions.
229  */
230 
231 void
232 readcmdfile(name)
233 	char *name;
234 	{
235 	int fd;
236 
237 	INTOFF;
238 	if ((fd = open(name, O_RDONLY)) >= 0)
239 		setinputfd(fd, 1);
240 	else
241 		error("Can't open %s", name);
242 	INTON;
243 	cmdloop(0);
244 	popfile();
245 }
246 
247 
248 
249 /*
250  * Take commands from a file.  To be compatable we should do a path
251  * search for the file, but a path search doesn't make any sense.
252  */
253 
254 dotcmd(argc, argv)  char **argv; {
255 	exitstatus = 0;
256 	if (argc >= 2) {		/* That's what SVR2 does */
257 		setinputfile(argv[1], 1);
258 		commandname = argv[1];
259 		cmdloop(0);
260 		popfile();
261 	}
262 	return exitstatus;
263 }
264 
265 
266 exitcmd(argc, argv)  char **argv; {
267 	if (argc > 1)
268 		exitstatus = number(argv[1]);
269 	exitshell(exitstatus);
270 }
271 
272 
273 lccmd(argc, argv)  char **argv; {
274 	if (argc > 1) {
275 		defun(argv[1], prevcmd);
276 		return 0;
277 	} else {
278 		INTOFF;
279 		freefunc(curcmd);
280 		curcmd = prevcmd;
281 		prevcmd = NULL;
282 		INTON;
283 		evaltree(curcmd, 0);
284 		return exitstatus;
285 	}
286 }
287 
288 
289 
290 #ifdef notdef
291 /*
292  * Should never be called.
293  */
294 
295 void
296 exit(exitstatus) {
297 	_exit(exitstatus);
298 }
299 #endif
300