1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <stdio.h>
36 #include <signal.h>
37 #include <sys/stat.h>
38 #include <unistd.h>
39 #include <fcntl.h>
40 #include <locale.h>
41 #include <errno.h>
42
43 #include "shell.h"
44 #include "main.h"
45 #include "mail.h"
46 #include "options.h"
47 #include "output.h"
48 #include "parser.h"
49 #include "nodes.h"
50 #include "expand.h"
51 #include "eval.h"
52 #include "jobs.h"
53 #include "input.h"
54 #include "trap.h"
55 #include "var.h"
56 #include "show.h"
57 #include "memalloc.h"
58 #include "error.h"
59 #include "mystring.h"
60 #include "exec.h"
61 #include "cd.h"
62 #include "redir.h"
63 #include "builtins.h"
64 #ifndef NO_HISTORY
65 #include "myhistedit.h"
66 #endif
67
68 int rootpid;
69 int rootshell;
70 struct jmploc main_handler;
71 int localeisutf8, initial_localeisutf8;
72
73 static void reset(void);
74 static void cmdloop(int);
75 static void read_profile(const char *);
76 static char *find_dot_file(char *);
77
78 /*
79 * Main routine. We initialize things, parse the arguments, execute
80 * profiles if we're a login shell, and then call cmdloop to execute
81 * commands. The setjmp call sets up the location to jump to when an
82 * exception occurs. When an exception occurs the variable "state"
83 * is used to figure out how far we had gotten.
84 */
85
86 int
main(int argc,char * argv[])87 main(int argc, char *argv[])
88 {
89 /*
90 * As smark is accessed after a longjmp, it cannot be a local in main().
91 * The C standard specifies that the values of non-volatile local
92 * variables are unspecified after a jump if modified between the
93 * setjmp and longjmp.
94 */
95 static struct stackmark smark, smark2;
96 volatile int state;
97 char *shinit;
98
99 (void) setlocale(LC_ALL, "");
100 initcharset();
101 state = 0;
102 if (setjmp(main_handler.loc)) {
103 if (state == 0 || iflag == 0 || ! rootshell ||
104 exception == EXEXIT)
105 exitshell(exitstatus);
106 reset();
107 if (exception == EXINT)
108 out2fmt_flush("\n");
109 popstackmark(&smark);
110 FORCEINTON; /* enable interrupts */
111 if (state == 1)
112 goto state1;
113 else if (state == 2)
114 goto state2;
115 else if (state == 3)
116 goto state3;
117 else
118 goto state4;
119 }
120 handler = &main_handler;
121 #ifdef DEBUG
122 opentrace();
123 trputs("Shell args: "); trargs(argv);
124 #endif
125 rootpid = getpid();
126 rootshell = 1;
127 INTOFF;
128 initvar();
129 setstackmark(&smark);
130 setstackmark(&smark2);
131 procargs(argc, argv);
132 trap_init();
133 pwd_init(iflag);
134 INTON;
135 if (iflag)
136 chkmail(1);
137 if (argv[0] && argv[0][0] == '-') {
138 state = 1;
139 read_profile("/etc/profile");
140 state1:
141 state = 2;
142 if (privileged == 0)
143 read_profile("${HOME-}/.profile");
144 else
145 read_profile("/etc/suid_profile");
146 }
147 state2:
148 state = 3;
149 if (!privileged && iflag) {
150 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
151 state = 3;
152 read_profile(shinit);
153 }
154 }
155 #ifndef NO_HISTORY
156 if (iflag)
157 histload();
158 #endif
159 state3:
160 state = 4;
161 popstackmark(&smark2);
162 if (minusc) {
163 evalstring(minusc, sflag ? 0 : EV_EXIT);
164 }
165 state4:
166 if (sflag || minusc == NULL) {
167 cmdloop(1);
168 }
169 exitshell(exitstatus);
170 /*NOTREACHED*/
171 return 0;
172 }
173
174 static void
reset(void)175 reset(void)
176 {
177 reseteval();
178 resetinput();
179 }
180
181 /*
182 * Read and execute commands. "Top" is nonzero for the top level command
183 * loop; it turns on prompting if the shell is interactive.
184 */
185
186 static void
cmdloop(int top)187 cmdloop(int top)
188 {
189 union node *n;
190 struct stackmark smark;
191 int inter;
192 int numeof = 0;
193
194 TRACE(("cmdloop(%d) called\n", top));
195 setstackmark(&smark);
196 for (;;) {
197 if (pendingsig)
198 dotrap();
199 inter = 0;
200 if (iflag && top) {
201 inter++;
202 showjobs(1, SHOWJOBS_DEFAULT);
203 chkmail(0);
204 flushout(&output);
205 }
206 n = parsecmd(inter);
207 /* showtree(n); DEBUG */
208 if (n == NEOF) {
209 if (!top || numeof >= 50)
210 break;
211 if (!stoppedjobs()) {
212 if (!Iflag)
213 break;
214 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
215 }
216 numeof++;
217 } else if (n != NULL && nflag == 0) {
218 job_warning = (job_warning == 2) ? 1 : 0;
219 numeof = 0;
220 evaltree(n, 0);
221 }
222 popstackmark(&smark);
223 setstackmark(&smark);
224 if (evalskip != 0) {
225 if (evalskip == SKIPRETURN)
226 evalskip = 0;
227 break;
228 }
229 }
230 popstackmark(&smark);
231 if (top && iflag) {
232 out2c('\n');
233 flushout(out2);
234 }
235 }
236
237
238
239 /*
240 * Read /etc/profile or .profile. Return on error.
241 */
242
243 static void
read_profile(const char * name)244 read_profile(const char *name)
245 {
246 int fd;
247 const char *expandedname;
248 int oflags = O_RDONLY | O_CLOEXEC;
249
250 if (verifyflag)
251 oflags |= O_VERIFY;
252
253 expandedname = expandstr(name);
254 if (expandedname == NULL)
255 return;
256 INTOFF;
257 if ((fd = open(expandedname, oflags)) >= 0)
258 setinputfd(fd, 1);
259 INTON;
260 if (fd < 0)
261 return;
262 cmdloop(0);
263 popfile();
264 }
265
266
267
268 /*
269 * Read a file containing shell functions.
270 */
271
272 void
readcmdfile(const char * name,int verify)273 readcmdfile(const char *name, int verify)
274 {
275 setinputfile(name, 1, verify);
276 cmdloop(0);
277 popfile();
278 }
279
280
281
282 /*
283 * Take commands from a file. To be compatible we should do a path
284 * search for the file, which is necessary to find sub-commands.
285 */
286
287
288 static char *
find_dot_file(char * basename)289 find_dot_file(char *basename)
290 {
291 char *fullname;
292 const char *opt;
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, &opt, 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, -1 /* verify */);
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