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 * 4. 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 static char const copyright[] =
35 "@(#) Copyright (c) 1991, 1993\n\
36 The Regents of the University of California. All rights reserved.\n";
37 #endif /* not lint */
38
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)main.c 8.6 (Berkeley) 5/28/95";
42 #endif
43 #endif /* not lint */
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD: stable/10/bin/sh/main.c 255215 2013-09-04 22:10:16Z jilles $");
46
47 #include <stdio.h>
48 #include <signal.h>
49 #include <sys/stat.h>
50 #include <unistd.h>
51 #include <fcntl.h>
52 #include <locale.h>
53 #include <errno.h>
54
55 #include "shell.h"
56 #include "main.h"
57 #include "mail.h"
58 #include "options.h"
59 #include "output.h"
60 #include "parser.h"
61 #include "nodes.h"
62 #include "expand.h"
63 #include "eval.h"
64 #include "jobs.h"
65 #include "input.h"
66 #include "trap.h"
67 #include "var.h"
68 #include "show.h"
69 #include "memalloc.h"
70 #include "error.h"
71 #include "mystring.h"
72 #include "exec.h"
73 #include "cd.h"
74 #include "redir.h"
75 #include "builtins.h"
76
77 int rootpid;
78 int rootshell;
79 struct jmploc main_handler;
80 int localeisutf8, initial_localeisutf8;
81
82 static void reset(void);
83 static void cmdloop(int);
84 static void read_profile(const char *);
85 static char *find_dot_file(char *);
86
87 /*
88 * Main routine. We initialize things, parse the arguments, execute
89 * profiles if we're a login shell, and then call cmdloop to execute
90 * commands. The setjmp call sets up the location to jump to when an
91 * exception occurs. When an exception occurs the variable "state"
92 * is used to figure out how far we had gotten.
93 */
94
95 int
main(int argc,char * argv[])96 main(int argc, char *argv[])
97 {
98 struct stackmark smark, smark2;
99 volatile int state;
100 char *shinit;
101
102 (void) setlocale(LC_ALL, "");
103 initcharset();
104 state = 0;
105 if (setjmp(main_handler.loc)) {
106 switch (exception) {
107 case EXEXEC:
108 exitstatus = exerrno;
109 break;
110
111 case EXERROR:
112 exitstatus = 2;
113 break;
114
115 default:
116 break;
117 }
118
119 if (state == 0 || iflag == 0 || ! rootshell ||
120 exception == EXEXIT)
121 exitshell(exitstatus);
122 reset();
123 if (exception == EXINT)
124 out2fmt_flush("\n");
125 popstackmark(&smark);
126 FORCEINTON; /* enable interrupts */
127 if (state == 1)
128 goto state1;
129 else if (state == 2)
130 goto state2;
131 else if (state == 3)
132 goto state3;
133 else
134 goto state4;
135 }
136 handler = &main_handler;
137 #ifdef DEBUG
138 opentrace();
139 trputs("Shell args: "); trargs(argv);
140 #endif
141 rootpid = getpid();
142 rootshell = 1;
143 initvar();
144 setstackmark(&smark);
145 setstackmark(&smark2);
146 procargs(argc, argv);
147 pwd_init(iflag);
148 if (iflag)
149 chkmail(1);
150 if (argv[0] && argv[0][0] == '-') {
151 state = 1;
152 read_profile("/etc/profile");
153 state1:
154 state = 2;
155 if (privileged == 0)
156 read_profile("${HOME-}/.profile");
157 else
158 read_profile("/etc/suid_profile");
159 }
160 state2:
161 state = 3;
162 if (!privileged && iflag) {
163 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
164 state = 3;
165 read_profile(shinit);
166 }
167 }
168 state3:
169 state = 4;
170 popstackmark(&smark2);
171 if (minusc) {
172 evalstring(minusc, sflag ? 0 : EV_EXIT);
173 }
174 state4:
175 if (sflag || minusc == NULL) {
176 cmdloop(1);
177 }
178 exitshell(exitstatus);
179 /*NOTREACHED*/
180 return 0;
181 }
182
183 static void
reset(void)184 reset(void)
185 {
186 reseteval();
187 resetinput();
188 }
189
190 /*
191 * Read and execute commands. "Top" is nonzero for the top level command
192 * loop; it turns on prompting if the shell is interactive.
193 */
194
195 static void
cmdloop(int top)196 cmdloop(int top)
197 {
198 union node *n;
199 struct stackmark smark;
200 int inter;
201 int numeof = 0;
202
203 TRACE(("cmdloop(%d) called\n", top));
204 setstackmark(&smark);
205 for (;;) {
206 if (pendingsig)
207 dotrap();
208 inter = 0;
209 if (iflag && top) {
210 inter++;
211 showjobs(1, SHOWJOBS_DEFAULT);
212 chkmail(0);
213 flushout(&output);
214 }
215 n = parsecmd(inter);
216 /* showtree(n); DEBUG */
217 if (n == NEOF) {
218 if (!top || numeof >= 50)
219 break;
220 if (!stoppedjobs()) {
221 if (!Iflag)
222 break;
223 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
224 }
225 numeof++;
226 } else if (n != NULL && nflag == 0) {
227 job_warning = (job_warning == 2) ? 1 : 0;
228 numeof = 0;
229 evaltree(n, 0);
230 }
231 popstackmark(&smark);
232 setstackmark(&smark);
233 if (evalskip != 0) {
234 if (evalskip == SKIPRETURN)
235 evalskip = 0;
236 break;
237 }
238 }
239 popstackmark(&smark);
240 }
241
242
243
244 /*
245 * Read /etc/profile or .profile. Return on error.
246 */
247
248 static void
read_profile(const char * name)249 read_profile(const char *name)
250 {
251 int fd;
252 const char *expandedname;
253
254 expandedname = expandstr(name);
255 if (expandedname == NULL)
256 return;
257 INTOFF;
258 if ((fd = open(expandedname, O_RDONLY | O_CLOEXEC)) >= 0)
259 setinputfd(fd, 1);
260 INTON;
261 if (fd < 0)
262 return;
263 cmdloop(0);
264 popfile();
265 }
266
267
268
269 /*
270 * Read a file containing shell functions.
271 */
272
273 void
readcmdfile(const char * name)274 readcmdfile(const char *name)
275 {
276 setinputfile(name, 1);
277 cmdloop(0);
278 popfile();
279 }
280
281
282
283 /*
284 * Take commands from a file. To be compatible we should do a path
285 * search for the file, which is necessary to find sub-commands.
286 */
287
288
289 static char *
find_dot_file(char * basename)290 find_dot_file(char *basename)
291 {
292 char *fullname;
293 const char *path = pathval();
294 struct stat statb;
295
296 /* don't try this for absolute or relative paths */
297 if( strchr(basename, '/'))
298 return basename;
299
300 while ((fullname = padvance(&path, basename)) != NULL) {
301 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
302 /*
303 * Don't bother freeing here, since it will
304 * be freed by the caller.
305 */
306 return fullname;
307 }
308 stunalloc(fullname);
309 }
310 return basename;
311 }
312
313 int
dotcmd(int argc,char ** argv)314 dotcmd(int argc, char **argv)
315 {
316 char *filename, *fullname;
317
318 if (argc < 2)
319 error("missing filename");
320
321 exitstatus = 0;
322
323 /*
324 * Because we have historically not supported any options,
325 * only treat "--" specially.
326 */
327 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
328
329 fullname = find_dot_file(filename);
330 setinputfile(fullname, 1);
331 commandname = fullname;
332 cmdloop(0);
333 popfile();
334 return exitstatus;
335 }
336
337
338 int
exitcmd(int argc,char ** argv)339 exitcmd(int argc, char **argv)
340 {
341 if (stoppedjobs())
342 return 0;
343 if (argc > 1)
344 exitshell(number(argv[1]));
345 else
346 exitshell_savedstatus();
347 }
348