xref: /original-bsd/bin/sh/main.c (revision 02e832b2)
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	5.8 (Berkeley) 10/15/92";
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 #include "var.h"
35 #include "memalloc.h"
36 #include "error.h"
37 #include "init.h"
38 #include "mystring.h"
39 
40 #define PROFILE 0
41 
42 int rootpid;
43 int rootshell;
44 STATIC union node *curcmd;
45 STATIC union node *prevcmd;
46 extern int errno;
47 #if PROFILE
48 short profile_buf[16384];
49 extern int etext();
50 #endif
51 
52 #ifdef __STDC__
53 STATIC void read_profile(char *);
54 char *getenv(char *);
55 #else
56 STATIC void read_profile();
57 char *getenv();
58 #endif
59 
60 
61 /*
62  * Main routine.  We initialize things, parse the arguments, execute
63  * profiles if we're a login shell, and then call cmdloop to execute
64  * commands.  The setjmp call sets up the location to jump to when an
65  * exception occurs.  When an exception occurs the variable "state"
66  * is used to figure out how far we had gotten.
67  */
68 
69 main(argc, argv)  char **argv; {
70 	struct jmploc jmploc;
71 	struct stackmark smark;
72 	volatile int state;
73 	char *shinit;
74 
75 #if PROFILE
76 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
77 #endif
78 	state = 0;
79 	if (setjmp(jmploc.loc)) {
80 		/*
81 		 * When a shell procedure is executed, we raise the
82 		 * exception EXSHELLPROC to clean up before executing
83 		 * the shell procedure.
84 		 */
85 		if (exception == EXSHELLPROC) {
86 			rootpid = getpid();
87 			rootshell = 1;
88 			minusc = NULL;
89 			state = 3;
90 		} else if (state == 0 || iflag == 0 || ! rootshell)
91 			exitshell(2);
92 		reset();
93 		if (exception == EXINT
94 #if ATTY
95 		 && (! attyset() || equal(termval(), "emacs"))
96 #endif
97 		 ) {
98 			out2c('\n');
99 			flushout(&errout);
100 		}
101 		popstackmark(&smark);
102 		FORCEINTON;				/* enable interrupts */
103 		if (state == 1)
104 			goto state1;
105 		else if (state == 2)
106 			goto state2;
107 		else if (state == 3)
108 			goto state3;
109 		else
110 			goto state4;
111 	}
112 	handler = &jmploc;
113 #ifdef DEBUG
114 	opentrace();
115 	trputs("Shell args:  ");  trargs(argv);
116 #endif
117 	rootpid = getpid();
118 	rootshell = 1;
119 	init();
120 	setstackmark(&smark);
121 	procargs(argc, argv);
122 	if (argv[0] && argv[0][0] == '-') {
123 		state = 1;
124 		read_profile("/etc/profile");
125 state1:
126 		state = 2;
127 		read_profile(".profile");
128 	}
129 state2:
130 	state = 3;
131 	if ((shinit = lookupvar("ENV")) != NULL &&
132 	     *shinit != '\0') {
133 		state = 3;
134 		read_profile(shinit);
135 	}
136 state3:
137 	state = 4;
138 	if (minusc) {
139 		evalstring(minusc);
140 	}
141 	if (sflag || minusc == NULL) {
142 state4:	/* XXX ??? - why isn't this before the "if" statement */
143 		cmdloop(1);
144 	}
145 #if PROFILE
146 	monitor(0);
147 #endif
148 	exitshell(exitstatus);
149 }
150 
151 
152 /*
153  * Read and execute commands.  "Top" is nonzero for the top level command
154  * loop; it turns on prompting if the shell is interactive.
155  */
156 
157 void
158 cmdloop(top) {
159 	union node *n;
160 	struct stackmark smark;
161 	int inter;
162 	int numeof = 0;
163 
164 	TRACE(("cmdloop(%d) called\n", top));
165 	setstackmark(&smark);
166 	for (;;) {
167 		if (pendingsigs)
168 			dotrap();
169 		inter = 0;
170 		if (iflag && top) {
171 			inter++;
172 			showjobs(1);
173 			chkmail(0);
174 			flushout(&output);
175 		}
176 		n = parsecmd(inter);
177 		/* showtree(n); DEBUG */
178 		if (n == NEOF) {
179 			if (!top || numeof >= 50)
180 				break;
181 			if (!stoppedjobs()) {
182 				if (!Iflag)
183 					break;
184 				out2str("\nUse \"exit\" to leave shell.\n");
185 			}
186 			numeof++;
187 		} else if (n != NULL && nflag == 0) {
188 			job_warning = (job_warning == 2) ? 1 : 0;
189 			numeof = 0;
190 			evaltree(n, 0);
191 		}
192 		popstackmark(&smark);
193 	}
194 	popstackmark(&smark);		/* unnecessary */
195 }
196 
197 
198 
199 /*
200  * Read /etc/profile or .profile.  Return on error.
201  */
202 
203 STATIC void
204 read_profile(name)
205 	char *name;
206 	{
207 	int fd;
208 
209 	INTOFF;
210 	if ((fd = open(name, O_RDONLY)) >= 0)
211 		setinputfd(fd, 1);
212 	INTON;
213 	if (fd < 0)
214 		return;
215 	cmdloop(0);
216 	popfile();
217 }
218 
219 
220 
221 /*
222  * Read a file containing shell functions.
223  */
224 
225 void
226 readcmdfile(name)
227 	char *name;
228 	{
229 	int fd;
230 
231 	INTOFF;
232 	if ((fd = open(name, O_RDONLY)) >= 0)
233 		setinputfd(fd, 1);
234 	else
235 		error("Can't open %s", name);
236 	INTON;
237 	cmdloop(0);
238 	popfile();
239 }
240 
241 
242 
243 /*
244  * Take commands from a file.  To be compatable we should do a path
245  * search for the file, but a path search doesn't make any sense.
246  */
247 
248 dotcmd(argc, argv)  char **argv; {
249 	exitstatus = 0;
250 	if (argc >= 2) {		/* That's what SVR2 does */
251 		setinputfile(argv[1], 1);
252 		commandname = argv[1];
253 		cmdloop(0);
254 		popfile();
255 	}
256 	return exitstatus;
257 }
258 
259 
260 exitcmd(argc, argv)  char **argv; {
261 	if (stoppedjobs())
262 		return;
263 	if (argc > 1)
264 		exitstatus = number(argv[1]);
265 	exitshell(exitstatus);
266 }
267 
268 
269 #ifdef notdef
270 /*
271  * Should never be called.
272  */
273 
274 void
275 exit(exitstatus) {
276 	_exit(exitstatus);
277 }
278 #endif
279