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 int login;
99
100 (void) setlocale(LC_ALL, "");
101 initcharset();
102 state = 0;
103 if (setjmp(main_handler.loc)) {
104 if (state == 0 || iflag == 0 || ! rootshell ||
105 exception == EXEXIT)
106 exitshell(exitstatus);
107 reset();
108 if (exception == EXINT)
109 out2fmt_flush("\n");
110 popstackmark(&smark);
111 FORCEINTON; /* enable interrupts */
112 if (state == 1)
113 goto state1;
114 else if (state == 2)
115 goto state2;
116 else if (state == 3)
117 goto state3;
118 else
119 goto state4;
120 }
121 handler = &main_handler;
122 #ifdef DEBUG
123 opentrace();
124 trputs("Shell args: "); trargs(argv);
125 #endif
126 rootpid = getpid();
127 rootshell = 1;
128 INTOFF;
129 initvar();
130 setstackmark(&smark);
131 setstackmark(&smark2);
132 login = procargs(argc, argv);
133 trap_init();
134 pwd_init(iflag);
135 INTON;
136 if (iflag)
137 chkmail(1);
138 if (login) {
139 state = 1;
140 read_profile("/etc/profile");
141 state1:
142 state = 2;
143 if (privileged == 0)
144 read_profile("${HOME-}/.profile");
145 else
146 read_profile("/etc/suid_profile");
147 }
148 state2:
149 state = 3;
150 if (!privileged && iflag) {
151 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
152 state = 3;
153 read_profile(shinit);
154 }
155 }
156 #ifndef NO_HISTORY
157 if (iflag)
158 histload();
159 #endif
160 state3:
161 state = 4;
162 popstackmark(&smark2);
163 if (minusc) {
164 evalstring(minusc, sflag ? 0 : EV_EXIT);
165 }
166 state4:
167 if (sflag || minusc == NULL) {
168 cmdloop(1);
169 }
170 exitshell(exitstatus);
171 /*NOTREACHED*/
172 return 0;
173 }
174
175 static void
reset(void)176 reset(void)
177 {
178 reseteval();
179 resetinput();
180 }
181
182 /*
183 * Read and execute commands. "Top" is nonzero for the top level command
184 * loop; it turns on prompting if the shell is interactive.
185 */
186
187 static void
cmdloop(int top)188 cmdloop(int top)
189 {
190 union node *n;
191 struct stackmark smark;
192 int inter;
193 int numeof = 0;
194
195 TRACE(("cmdloop(%d) called\n", top));
196 setstackmark(&smark);
197 for (;;) {
198 if (pendingsig)
199 dotrap();
200 inter = 0;
201 if (iflag && top) {
202 inter++;
203 showjobs(1, SHOWJOBS_DEFAULT);
204 chkmail(0);
205 flushout(&output);
206 }
207 n = parsecmd(inter);
208 /* showtree(n); DEBUG */
209 if (n == NEOF) {
210 if (!top || numeof >= 50)
211 break;
212 if (!stoppedjobs()) {
213 if (!Iflag)
214 break;
215 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
216 }
217 numeof++;
218 } else if (n != NULL && nflag == 0) {
219 job_warning = (job_warning == 2) ? 1 : 0;
220 numeof = 0;
221 evaltree(n, 0);
222 }
223 popstackmark(&smark);
224 setstackmark(&smark);
225 if (evalskip != 0) {
226 if (evalskip == SKIPRETURN)
227 evalskip = 0;
228 break;
229 }
230 }
231 popstackmark(&smark);
232 if (top && iflag) {
233 out2c('\n');
234 flushout(out2);
235 }
236 }
237
238
239
240 /*
241 * Read /etc/profile or .profile. Return on error.
242 */
243
244 static void
read_profile(const char * name)245 read_profile(const char *name)
246 {
247 int fd;
248 const char *expandedname;
249 int oflags = O_RDONLY | O_CLOEXEC;
250
251 if (verifyflag)
252 oflags |= O_VERIFY;
253
254 expandedname = expandstr(name);
255 if (expandedname == NULL)
256 return;
257 INTOFF;
258 if ((fd = open(expandedname, oflags)) >= 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,int verify)274 readcmdfile(const char *name, int verify)
275 {
276 setinputfile(name, 1, verify);
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 *opt;
294 const char *path = pathval();
295 struct stat statb;
296
297 /* don't try this for absolute or relative paths */
298 if( strchr(basename, '/'))
299 return basename;
300
301 while ((fullname = padvance(&path, &opt, basename)) != NULL) {
302 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
303 /*
304 * Don't bother freeing here, since it will
305 * be freed by the caller.
306 */
307 return fullname;
308 }
309 stunalloc(fullname);
310 }
311 return basename;
312 }
313
314 int
dotcmd(int argc,char ** argv)315 dotcmd(int argc, char **argv)
316 {
317 char *filename, *fullname;
318
319 if (argc < 2)
320 error("missing filename");
321
322 exitstatus = 0;
323
324 /*
325 * Because we have historically not supported any options,
326 * only treat "--" specially.
327 */
328 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
329
330 fullname = find_dot_file(filename);
331 setinputfile(fullname, 1, -1 /* verify */);
332 commandname = fullname;
333 cmdloop(0);
334 popfile();
335 return exitstatus;
336 }
337
338
339 int
exitcmd(int argc,char ** argv)340 exitcmd(int argc, char **argv)
341 {
342 if (stoppedjobs())
343 return 0;
344 if (argc > 1)
345 exitshell(number(argv[1]));
346 else
347 exitshell_savedstatus();
348 }
349