xref: /original-bsd/bin/sh/main.c (revision 7b9eb693)
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	5.7 (Berkeley) 07/16/92";
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 ATTY
94 		if (exception == EXINT
95 		 && (! attyset() || equal(termval(), "emacs"))) {
96 #else
97 		if (exception == EXINT) {
98 #endif
99 			out2c('\n');
100 			flushout(&errout);
101 		}
102 		popstackmark(&smark);
103 		FORCEINTON;				/* enable interrupts */
104 		if (state == 1)
105 			goto state1;
106 		else if (state == 2)
107 			goto state2;
108 		else if (state == 3)
109 			goto state3;
110 		else
111 			goto state4;
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 	}
130 state2:
131 	state = 3;
132 	if ((shinit = lookupvar("ENV")) != NULL &&
133 	     *shinit != '\0') {
134 		state = 3;
135 		read_profile(shinit);
136 	}
137 state3:
138 	state = 4;
139 	if (minusc) {
140 		evalstring(minusc);
141 	}
142 	if (sflag || minusc == NULL) {
143 state4:	/* XXX ??? - why isn't this before the "if" statement */
144 		cmdloop(1);
145 	}
146 #if PROFILE
147 	monitor(0);
148 #endif
149 	exitshell(exitstatus);
150 }
151 
152 
153 /*
154  * Read and execute commands.  "Top" is nonzero for the top level command
155  * loop; it turns on prompting if the shell is interactive.
156  */
157 
158 void
159 cmdloop(top) {
160 	union node *n;
161 	struct stackmark smark;
162 	int inter;
163 	int numeof = 0;
164 
165 	TRACE(("cmdloop(%d) called\n", top));
166 	setstackmark(&smark);
167 	for (;;) {
168 		if (pendingsigs)
169 			dotrap();
170 		inter = 0;
171 		if (iflag && top) {
172 			inter++;
173 			showjobs(1);
174 			chkmail(0);
175 			flushout(&output);
176 		}
177 		n = parsecmd(inter);
178 		/* showtree(n); DEBUG */
179 		if (n == NEOF) {
180 			if (!top || numeof >= 50)
181 				break;
182 			if (!stoppedjobs()) {
183 				if (!Iflag)
184 					break;
185 				out2str("\nUse \"exit\" to leave shell.\n");
186 			}
187 			numeof++;
188 		} else if (n != NULL && nflag == 0) {
189 			job_warning = (job_warning == 2) ? 1 : 0;
190 			numeof = 0;
191 			evaltree(n, 0);
192 		}
193 		popstackmark(&smark);
194 	}
195 	popstackmark(&smark);		/* unnecessary */
196 }
197 
198 
199 
200 /*
201  * Read /etc/profile or .profile.  Return on error.
202  */
203 
204 STATIC void
205 read_profile(name)
206 	char *name;
207 	{
208 	int fd;
209 
210 	INTOFF;
211 	if ((fd = open(name, O_RDONLY)) >= 0)
212 		setinputfd(fd, 1);
213 	INTON;
214 	if (fd < 0)
215 		return;
216 	cmdloop(0);
217 	popfile();
218 }
219 
220 
221 
222 /*
223  * Read a file containing shell functions.
224  */
225 
226 void
227 readcmdfile(name)
228 	char *name;
229 	{
230 	int fd;
231 
232 	INTOFF;
233 	if ((fd = open(name, O_RDONLY)) >= 0)
234 		setinputfd(fd, 1);
235 	else
236 		error("Can't open %s", name);
237 	INTON;
238 	cmdloop(0);
239 	popfile();
240 }
241 
242 
243 
244 /*
245  * Take commands from a file.  To be compatable we should do a path
246  * search for the file, but a path search doesn't make any sense.
247  */
248 
249 dotcmd(argc, argv)  char **argv; {
250 	exitstatus = 0;
251 	if (argc >= 2) {		/* That's what SVR2 does */
252 		setinputfile(argv[1], 1);
253 		commandname = argv[1];
254 		cmdloop(0);
255 		popfile();
256 	}
257 	return exitstatus;
258 }
259 
260 
261 exitcmd(argc, argv)  char **argv; {
262 	if (stoppedjobs())
263 		return;
264 	if (argc > 1)
265 		exitstatus = number(argv[1]);
266 	exitshell(exitstatus);
267 }
268 
269 
270 #ifdef notdef
271 /*
272  * Should never be called.
273  */
274 
275 void
276 exit(exitstatus) {
277 	_exit(exitstatus);
278 }
279 #endif
280