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 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 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 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 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 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 * 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 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 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