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 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)main.c 8.6 (Berkeley) 5/28/95"; 38 #endif 39 #endif /* not lint */ 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD: head/bin/sh/main.c 364919 2020-08-28 15:35:45Z jilles $"); 42 43 #include <stdio.h> 44 #include <signal.h> 45 #include <sys/stat.h> 46 #include <unistd.h> 47 #include <fcntl.h> 48 #include <locale.h> 49 #include <errno.h> 50 51 #include "shell.h" 52 #include "main.h" 53 #include "mail.h" 54 #include "options.h" 55 #include "output.h" 56 #include "parser.h" 57 #include "nodes.h" 58 #include "expand.h" 59 #include "eval.h" 60 #include "jobs.h" 61 #include "input.h" 62 #include "trap.h" 63 #include "var.h" 64 #include "show.h" 65 #include "memalloc.h" 66 #include "error.h" 67 #include "mystring.h" 68 #include "exec.h" 69 #include "cd.h" 70 #include "redir.h" 71 #include "builtins.h" 72 73 int rootpid; 74 int rootshell; 75 struct jmploc main_handler; 76 int localeisutf8, initial_localeisutf8; 77 78 static void reset(void); 79 static void cmdloop(int); 80 static void read_profile(const char *); 81 static char *find_dot_file(char *); 82 83 /* 84 * Main routine. We initialize things, parse the arguments, execute 85 * profiles if we're a login shell, and then call cmdloop to execute 86 * commands. The setjmp call sets up the location to jump to when an 87 * exception occurs. When an exception occurs the variable "state" 88 * is used to figure out how far we had gotten. 89 */ 90 91 int 92 main(int argc, char *argv[]) 93 { 94 struct stackmark smark, smark2; 95 volatile int state; 96 char *shinit; 97 98 (void) setlocale(LC_ALL, ""); 99 initcharset(); 100 state = 0; 101 if (setjmp(main_handler.loc)) { 102 if (state == 0 || iflag == 0 || ! rootshell || 103 exception == EXEXIT) 104 exitshell(exitstatus); 105 reset(); 106 if (exception == EXINT) 107 out2fmt_flush("\n"); 108 popstackmark(&smark); 109 FORCEINTON; /* enable interrupts */ 110 if (state == 1) 111 goto state1; 112 else if (state == 2) 113 goto state2; 114 else if (state == 3) 115 goto state3; 116 else 117 goto state4; 118 } 119 handler = &main_handler; 120 #ifdef DEBUG 121 opentrace(); 122 trputs("Shell args: "); trargs(argv); 123 #endif 124 rootpid = getpid(); 125 rootshell = 1; 126 INTOFF; 127 initvar(); 128 setstackmark(&smark); 129 setstackmark(&smark2); 130 procargs(argc, argv); 131 trap_init(); 132 pwd_init(iflag); 133 INTON; 134 if (iflag) 135 chkmail(1); 136 if (argv[0] && argv[0][0] == '-') { 137 state = 1; 138 read_profile("/etc/profile"); 139 state1: 140 state = 2; 141 if (privileged == 0) 142 read_profile("${HOME-}/.profile"); 143 else 144 read_profile("/etc/suid_profile"); 145 } 146 state2: 147 state = 3; 148 if (!privileged && iflag) { 149 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') { 150 state = 3; 151 read_profile(shinit); 152 } 153 } 154 state3: 155 state = 4; 156 popstackmark(&smark2); 157 if (minusc) { 158 evalstring(minusc, sflag ? 0 : EV_EXIT); 159 } 160 state4: 161 if (sflag || minusc == NULL) { 162 cmdloop(1); 163 } 164 exitshell(exitstatus); 165 /*NOTREACHED*/ 166 return 0; 167 } 168 169 static void 170 reset(void) 171 { 172 reseteval(); 173 resetinput(); 174 } 175 176 /* 177 * Read and execute commands. "Top" is nonzero for the top level command 178 * loop; it turns on prompting if the shell is interactive. 179 */ 180 181 static void 182 cmdloop(int top) 183 { 184 union node *n; 185 struct stackmark smark; 186 int inter; 187 int numeof = 0; 188 189 TRACE(("cmdloop(%d) called\n", top)); 190 setstackmark(&smark); 191 for (;;) { 192 if (pendingsig) 193 dotrap(); 194 inter = 0; 195 if (iflag && top) { 196 inter++; 197 showjobs(1, SHOWJOBS_DEFAULT); 198 chkmail(0); 199 flushout(&output); 200 } 201 n = parsecmd(inter); 202 /* showtree(n); DEBUG */ 203 if (n == NEOF) { 204 if (!top || numeof >= 50) 205 break; 206 if (!stoppedjobs()) { 207 if (!Iflag) 208 break; 209 out2fmt_flush("\nUse \"exit\" to leave shell.\n"); 210 } 211 numeof++; 212 } else if (n != NULL && nflag == 0) { 213 job_warning = (job_warning == 2) ? 1 : 0; 214 numeof = 0; 215 evaltree(n, 0); 216 } 217 popstackmark(&smark); 218 setstackmark(&smark); 219 if (evalskip != 0) { 220 if (evalskip == SKIPRETURN) 221 evalskip = 0; 222 break; 223 } 224 } 225 popstackmark(&smark); 226 if (top && iflag) { 227 out2c('\n'); 228 flushout(out2); 229 } 230 } 231 232 233 234 /* 235 * Read /etc/profile or .profile. Return on error. 236 */ 237 238 static void 239 read_profile(const char *name) 240 { 241 int fd; 242 const char *expandedname; 243 244 expandedname = expandstr(name); 245 if (expandedname == NULL) 246 return; 247 INTOFF; 248 if ((fd = open(expandedname, O_RDONLY | O_CLOEXEC_MAYBE)) >= 0) 249 setinputfd(fd, 1); 250 INTON; 251 if (fd < 0) 252 return; 253 cmdloop(0); 254 popfile(); 255 } 256 257 258 259 /* 260 * Read a file containing shell functions. 261 */ 262 263 void 264 readcmdfile(const char *name) 265 { 266 setinputfile(name, 1); 267 cmdloop(0); 268 popfile(); 269 } 270 271 272 273 /* 274 * Take commands from a file. To be compatible we should do a path 275 * search for the file, which is necessary to find sub-commands. 276 */ 277 278 279 static char * 280 find_dot_file(char *basename) 281 { 282 char *fullname; 283 const char *opt; 284 const char *path = pathval(); 285 struct stat statb; 286 287 /* don't try this for absolute or relative paths */ 288 if( strchr(basename, '/')) 289 return basename; 290 291 while ((fullname = padvance(&path, &opt, basename)) != NULL) { 292 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) { 293 /* 294 * Don't bother freeing here, since it will 295 * be freed by the caller. 296 */ 297 return fullname; 298 } 299 stunalloc(fullname); 300 } 301 return basename; 302 } 303 304 int 305 dotcmd(int argc, char **argv) 306 { 307 char *filename, *fullname; 308 309 if (argc < 2) 310 error("missing filename"); 311 312 exitstatus = 0; 313 314 /* 315 * Because we have historically not supported any options, 316 * only treat "--" specially. 317 */ 318 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1]; 319 320 fullname = find_dot_file(filename); 321 setinputfile(fullname, 1); 322 commandname = fullname; 323 cmdloop(0); 324 popfile(); 325 return exitstatus; 326 } 327 328 329 int 330 exitcmd(int argc, char **argv) 331 { 332 if (stoppedjobs()) 333 return 0; 334 if (argc > 1) 335 exitshell(number(argv[1])); 336 else 337 exitshell_savedstatus(); 338 } 339