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#include <termios.h>
43#include <paths.h>
44#include <unistd.h>
45
46#include "shell.h"
47#include "main.h"
48#include "mail.h"
49#include "options.h"
50#include "output.h"
51#include "parser.h"
52#include "nodes.h"
53#include "expand.h"
54#include "eval.h"
55#include "jobs.h"
56#include "input.h"
57#include "trap.h"
58#include "var.h"
59#include "show.h"
60#include "memalloc.h"
61#include "error.h"
62#include "mystring.h"
63#include "exec.h"
64#include "cd.h"
65#include "redir.h"
66#include "builtins.h"
67#ifndef NO_HISTORY
68#include "lineedit.h"
69#endif
70
71int rootpid;
72int rootshell;
73struct jmploc main_handler;
74int localeisutf8, initial_localeisutf8;
75
76static void reset(void);
77static void cmdloop(int);
78static void read_profile(const char *);
79static char *find_dot_file(char *);
80
81/*
82 * Main routine. We initialize things, parse the arguments, execute
83 * profiles if we're a login shell, and then call cmdloop to execute
84 * commands. The setjmp call sets up the location to jump to when an
85 * exception occurs. When an exception occurs the variable "state"
86 * is used to figure out how far we had gotten.
87 */
88
89int
90main(int argc, char *argv[])
91{
92 /*
93 * As smark is accessed after a longjmp, it cannot be a local in main().
94 * The C standard specifies that the values of non-volatile local
95 * variables are unspecified after a jump if modified between the
96 * setjmp and longjmp.
97 */
98 static struct stackmark smark, smark2;
99 volatile int state;
100 char *shinit;
101 int login;
102
103 (void) setlocale(LC_ALL, "");
104 initcharset();
105 state = 0;
106 if (setjmp(main_handler.loc)) {
107 if (state == 0 || iflag == 0 || ! rootshell ||
108 exception == EXEXIT)
109 exitshell(exitstatus);
110 reset();
111 if (exception == EXINT)
112 out2fmt_flush("\n");
113 popstackmark(&smark);
114 FORCEINTON; /* enable interrupts */
115 if (state == 1)
116 goto state1;
117 else if (state == 2)
118 goto state2;
119 else if (state == 3)
120 goto state3;
121 else
122 goto state4;
123 }
124 handler = &main_handler;
125#ifdef DEBUG
126 opentrace();
127 trputs("Shell args: "); trargs(argv);
128#endif
129 rootpid = getpid();
130 if (rootpid == 1) {
131 /*
132 * Make sh usable for invocation as interactive init
133 * substitute with init_path=/bin/sh, by opening
134 * file descriptors 0, 1, and 2 on /dev/console.
135 */
136 if (fcntl(STDIN_FILENO, F_GETFL, NULL) == -1 && errno == EBADF) {
137 (void)open(_PATH_CONSOLE, O_RDWR);
138 (void)setsid();
139 (void)tcsetsid(STDIN_FILENO, rootpid);
140 }
141 if (fcntl(STDOUT_FILENO, F_GETFL, NULL) == -1 && errno == EBADF)
142 (void)dup2(STDIN_FILENO, STDOUT_FILENO);
143 if (fcntl(STDERR_FILENO, F_GETFL, NULL) == -1 && errno == EBADF)
144 (void)dup2(STDIN_FILENO, STDERR_FILENO);
145 }
146 rootshell = 1;
147 INTOFF;
148 initvar();
149 setstackmark(&smark);
150 setstackmark(&smark2);
151 login = procargs(argc, argv);
152 trap_init();
153 pwd_init(iflag);
154 INTON;
155 if (iflag)
156 chkmail(1);
157 if (login) {
158 state = 1;
159 read_profile("/etc/profile");
160state1:
161 state = 2;
162 if (privileged == 0)
163 read_profile("${HOME-}/.profile");
164 else
165 read_profile("/etc/suid_profile");
166 }
167state2:
168 state = 3;
169 if (!privileged && iflag) {
170 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
171 state = 3;
172 read_profile(shinit);
173 }
174 }
175#ifndef NO_HISTORY
176 if (iflag)
177 histload();
178#endif
179state3:
180 state = 4;
181 popstackmark(&smark2);
182 if (minusc) {
183 evalstring(minusc, sflag ? 0 : EV_EXIT);
184 }
185state4:
186 if (sflag || minusc == NULL) {
187 cmdloop(1);
188 }
189 exitshell(exitstatus);
190 /*NOTREACHED*/
191 return 0;
192}
193
194static void
195reset(void)
196{
197 reseteval();
198 resetinput();
199}
200
201/*
202 * Read and execute commands. "Top" is nonzero for the top level command
203 * loop; it turns on prompting if the shell is interactive.
204 */
205
206static void
207cmdloop(int top)
208{
209 union node *n;
210 struct stackmark smark;
211 int inter;
212 int numeof = 0;
213
214 TRACE(("cmdloop(%d) called\n", top));
215 setstackmark(&smark);
216 for (;;) {
217 if (pendingsig)
218 dotrap();
219 inter = 0;
220 if (iflag && top) {
221 inter++;
222 showjobs(1, SHOWJOBS_DEFAULT);
223 chkmail(0);
224 flushout(&output);
225 }
226 n = parsecmd(inter);
227 /* showtree(n); DEBUG */
228 if (n == NEOF) {
229 if (!top || numeof >= 50)
230 break;
231 if (!stoppedjobs()) {
232 if (!Iflag)
233 break;
234 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
235 }
236 numeof++;
237 } else if (n != NULL && nflag == 0) {
238 job_warning = (job_warning == 2) ? 1 : 0;
239 numeof = 0;
240 evaltree(n, 0);
241 }
242 popstackmark(&smark);
243 setstackmark(&smark);
244 if (evalskip != 0) {
245 if (evalskip == SKIPRETURN)
246 evalskip = 0;
247 break;
248 }
249 }
250 popstackmark(&smark);
251 if (top && iflag) {
252 out2c('\n');
253 flushout(out2);
254 }
255}
256
257
258
259/*
260 * Read /etc/profile or .profile. Return on error.
261 */
262
263static void
264read_profile(const char *name)
265{
266 int fd;
267 const char *expandedname;
268 int oflags = O_RDONLY | O_CLOEXEC;
269
270 if (verifyflag)
271 oflags |= O_VERIFY;
272
273 expandedname = expandstr(name);
274 if (expandedname == NULL)
275 return;
276 INTOFF;
277 if ((fd = open(expandedname, oflags)) >= 0)
278 setinputfd(fd, 1);
279 INTON;
280 if (fd < 0)
281 return;
282 cmdloop(0);
283 popfile();
284}
285
286
287
288/*
289 * Read a file containing shell functions.
290 */
291
292void
293readcmdfile(const char *name, int verify)
294{
295 setinputfile(name, 1, verify);
296 cmdloop(0);
297 popfile();
298}
299
300
301
302/*
303 * Take commands from a file. To be compatible we should do a path
304 * search for the file, which is necessary to find sub-commands.
305 */
306
307
308static char *
309find_dot_file(char *basename)
310{
311 char *fullname;
312 const char *opt;
313 const char *path = pathval();
314 struct stat statb;
315
316 /* don't try this for absolute or relative paths */
317 if( strchr(basename, '/'))
318 return basename;
319
320 while ((fullname = padvance(&path, &opt, basename)) != NULL) {
321 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
322 /*
323 * Don't bother freeing here, since it will
324 * be freed by the caller.
325 */
326 return fullname;
327 }
328 stunalloc(fullname);
329 }
330 return basename;
331}
332
333int
334dotcmd(int argc, char **argv)
335{
336 char *filename, *fullname;
337
338 if (argc < 2)
339 error("missing filename");
340
341 exitstatus = 0;
342
343 /*
344 * Because we have historically not supported any options,
345 * only treat "--" specially.
346 */
347 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
348
349 fullname = find_dot_file(filename);
350 setinputfile(fullname, 1, -1 /* verify */);
351 commandname = fullname;
352 cmdloop(0);
353 popfile();
354 return exitstatus;
355}
356
357
358int
359exitcmd(int argc, char **argv)
360{
361 if (stoppedjobs())
362 return 0;
363 if (argc > 1)
364 exitshell(number(argv[1]));
365 else
366 exitshell_savedstatus();
367}
