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 <errno.h>
36#include <fcntl.h>
37#include <locale.h>
38#include <signal.h>
39#include <stdio.h>
40#include <sys/stat.h>
41#include <termios.h>
42#include <unistd.h>
43
44#include "../../../shared/paths.h"
45#include "../../../shared/wexec.h"
46#include "builtins.h"
47#include "cd.h"
48#include "error.h"
49#include "eval.h"
50#include "exec.h"
51#include "expand.h"
52#include "input.h"
53#include "jobs.h"
54#include "mail.h"
55#include "main.h"
56#include "memalloc.h"
57#include "mystring.h"
58#include "nodes.h"
59#include "options.h"
60#include "output.h"
61#include "parser.h"
62#include "redir.h"
63#include "shell.h"
64#include "show.h"
65#include "trap.h"
66#include "var.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 wexec_register_env_lookup(lookupvar);
105 initcharset();
106 state = 0;
107 if (setjmp(main_handler.loc)) {
108 if (state == 0 || iflag == 0 || !rootshell || 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: ");
128 trargs(argv);
129#endif
130 rootpid = getpid();
131 if (rootpid == 1) {
132 /*
133 * Make sh usable for invocation as interactive init
134 * substitute with init_path=/bin/sh, by opening
135 * file descriptors 0, 1, and 2 on /dev/console.
136 */
137 if (fcntl(STDIN_FILENO, F_GETFL, NULL) == -1 && errno == EBADF) {
138 (void)open(ARUU_PATH_DEVCONSOLE, O_RDWR);
139 (void)setsid();
140 (void)tcsetsid(STDIN_FILENO, rootpid);
141 }
142 if (fcntl(STDOUT_FILENO, F_GETFL, NULL) == -1 && errno == EBADF)
143 (void)dup2(STDIN_FILENO, STDOUT_FILENO);
144 if (fcntl(STDERR_FILENO, F_GETFL, NULL) == -1 && errno == EBADF)
145 (void)dup2(STDIN_FILENO, STDERR_FILENO);
146 }
147 rootshell = 1;
148 INTOFF;
149 initvar();
150 setstackmark(&smark);
151 setstackmark(&smark2);
152 login = procargs(argc, argv);
153 trap_init();
154 pwd_init(iflag);
155 INTON;
156 if (iflag)
157 chkmail(1);
158 if (login) {
159 state = 1;
160 read_profile("/etc/profile");
161 state1:
162 state = 2;
163 if (privileged == 0)
164 read_profile("${HOME-}/.profile");
165 else
166 read_profile("/etc/suid_profile");
167 }
168state2:
169 state = 3;
170 if (!privileged && iflag) {
171 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
172 state = 3;
173 read_profile(shinit);
174 }
175 }
176#ifndef NO_HISTORY
177 if (iflag)
178 histload();
179#endif
180state3:
181 state = 4;
182 popstackmark(&smark2);
183 if (minusc) {
184 evalstring(minusc, sflag ? 0 : EV_EXIT);
185 }
186state4:
187 if (sflag || minusc == NULL) {
188 cmdloop(1);
189 }
190 exitshell(exitstatus);
191 /*NOTREACHED*/
192 return 0;
193}
194
195static void
196reset(void)
197{
198 reseteval();
199 resetinput();
200}
201
202/*
203 * Read and execute commands. "Top" is nonzero for the top level command
204 * loop; it turns on prompting if the shell is interactive.
205 */
206
207static void
208cmdloop(int top)
209{
210 union node *n;
211 struct stackmark smark;
212 int inter;
213 int numeof = 0;
214
215 TRACE(("cmdloop(%d) called\n", top));
216 setstackmark(&smark);
217 for (;;) {
218 if (pendingsig)
219 dotrap();
220 inter = 0;
221 if (iflag && top) {
222 inter++;
223 showjobs(1, SHOWJOBS_DEFAULT);
224 chkmail(0);
225 flushout(&output);
226 }
227 n = parsecmd(inter);
228 /* showtree(n); DEBUG */
229 if (n == NEOF) {
230 if (!top || numeof >= 50)
231 break;
232 if (!stoppedjobs()) {
233 if (!Iflag)
234 break;
235 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
236 }
237 numeof++;
238 } else if (n != NULL && nflag == 0) {
239 job_warning = (job_warning == 2) ? 1 : 0;
240 numeof = 0;
241 evaltree(n, 0);
242 }
243 popstackmark(&smark);
244 setstackmark(&smark);
245 if (evalskip != 0) {
246 if (evalskip == SKIPRETURN)
247 evalskip = 0;
248 break;
249 }
250 }
251 popstackmark(&smark);
252 if (top && iflag) {
253 out2c('\n');
254 flushout(out2);
255 }
256}
257
258/*
259 * Read /etc/profile or .profile. Return on error.
260 */
261
262static void
263read_profile(const char *name)
264{
265 int fd;
266 const char *expandedname;
267 int oflags = O_RDONLY | O_CLOEXEC;
268
269 if (verifyflag)
270 oflags |= O_VERIFY;
271
272 expandedname = expandstr(name);
273 if (expandedname == NULL)
274 return;
275 INTOFF;
276 if ((fd = open(expandedname, oflags)) >= 0)
277 setinputfd(fd, 1);
278 INTON;
279 if (fd < 0)
280 return;
281 cmdloop(0);
282 popfile();
283}
284
285/*
286 * Read a file containing shell functions.
287 */
288
289void
290readcmdfile(const char *name, int verify)
291{
292 setinputfile(name, 1, verify);
293 cmdloop(0);
294 popfile();
295}
296
297/*
298 * Take commands from a file. To be compatible we should do a path
299 * search for the file, which is necessary to find sub-commands.
300 */
301
302static char *
303find_dot_file(char *basename)
304{
305 char *fullname;
306 const char *opt;
307 const char *path = pathval();
308 struct stat statb;
309
310 /* don't try this for absolute or relative paths */
311 if (strchr(basename, '/'))
312 return basename;
313
314 while ((fullname = padvance(&path, &opt, basename)) != NULL) {
315 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
316 /*
317 * Don't bother freeing here, since it will
318 * be freed by the caller.
319 */
320 return fullname;
321 }
322 stunalloc(fullname);
323 }
324 return basename;
325}
326
327int
328dotcmd(int argc, char **argv)
329{
330 char *filename, *fullname;
331
332 if (argc < 2)
333 error("missing filename");
334
335 exitstatus = 0;
336
337 /*
338 * Because we have historically not supported any options,
339 * only treat "--" specially.
340 */
341 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
342
343 fullname = find_dot_file(filename);
344 setinputfile(fullname, 1, -1 /* verify */);
345 commandname = fullname;
346 cmdloop(0);
347 popfile();
348 return exitstatus;
349}
350
351int
352exitcmd(int argc, char **argv)
353{
354 if (stoppedjobs())
355 return 0;
356 if (argc > 1)
357 exitshell(number(argv[1]));
358 else
359 exitshell_savedstatus();
360}
