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 99 (void) setlocale(LC_ALL, ""); 100 initcharset(); 101 state = 0; 102 if (setjmp(main_handler.loc)) { 103 if (state == 0 || iflag == 0 || ! rootshell || 104 exception == EXEXIT) 105 exitshell(exitstatus); 106 reset(); 107 if (exception == EXINT) 108 out2fmt_flush("\n"); 109 popstackmark(&smark); 110 FORCEINTON; /* enable interrupts */ 111 if (state == 1) 112 goto state1; 113 else if (state == 2) 114 goto state2; 115 else if (state == 3) 116 goto state3; 117 else 118 goto state4; 119 } 120 handler = &main_handler; 121 #ifdef DEBUG 122 opentrace(); 123 trputs("Shell args: "); trargs(argv); 124 #endif 125 rootpid = getpid(); 126 rootshell = 1; 127 INTOFF; 128 initvar(); 129 setstackmark(&smark); 130 setstackmark(&smark2); 131 procargs(argc, argv); 132 trap_init(); 133 pwd_init(iflag); 134 INTON; 135 if (iflag) 136 chkmail(1); 137 if (argv[0] && argv[0][0] == '-') { 138 state = 1; 139 read_profile("/etc/profile"); 140 state1: 141 state = 2; 142 if (privileged == 0) 143 read_profile("${HOME-}/.profile"); 144 else 145 read_profile("/etc/suid_profile"); 146 } 147 state2: 148 state = 3; 149 if (!privileged && iflag) { 150 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') { 151 state = 3; 152 read_profile(shinit); 153 } 154 } 155 #ifndef NO_HISTORY 156 if (iflag) 157 histload(); 158 #endif 159 state3: 160 state = 4; 161 popstackmark(&smark2); 162 if (minusc) { 163 evalstring(minusc, sflag ? 0 : EV_EXIT); 164 } 165 state4: 166 if (sflag || minusc == NULL) { 167 cmdloop(1); 168 } 169 exitshell(exitstatus); 170 /*NOTREACHED*/ 171 return 0; 172 } 173 174 static void 175 reset(void) 176 { 177 reseteval(); 178 resetinput(); 179 } 180 181 /* 182 * Read and execute commands. "Top" is nonzero for the top level command 183 * loop; it turns on prompting if the shell is interactive. 184 */ 185 186 static void 187 cmdloop(int top) 188 { 189 union node *n; 190 struct stackmark smark; 191 int inter; 192 int numeof = 0; 193 194 TRACE(("cmdloop(%d) called\n", top)); 195 setstackmark(&smark); 196 for (;;) { 197 if (pendingsig) 198 dotrap(); 199 inter = 0; 200 if (iflag && top) { 201 inter++; 202 showjobs(1, SHOWJOBS_DEFAULT); 203 chkmail(0); 204 flushout(&output); 205 } 206 n = parsecmd(inter); 207 /* showtree(n); DEBUG */ 208 if (n == NEOF) { 209 if (!top || numeof >= 50) 210 break; 211 if (!stoppedjobs()) { 212 if (!Iflag) 213 break; 214 out2fmt_flush("\nUse \"exit\" to leave shell.\n"); 215 } 216 numeof++; 217 } else if (n != NULL && nflag == 0) { 218 job_warning = (job_warning == 2) ? 1 : 0; 219 numeof = 0; 220 evaltree(n, 0); 221 } 222 popstackmark(&smark); 223 setstackmark(&smark); 224 if (evalskip != 0) { 225 if (evalskip == SKIPRETURN) 226 evalskip = 0; 227 break; 228 } 229 } 230 popstackmark(&smark); 231 if (top && iflag) { 232 out2c('\n'); 233 flushout(out2); 234 } 235 } 236 237 238 239 /* 240 * Read /etc/profile or .profile. Return on error. 241 */ 242 243 static void 244 read_profile(const char *name) 245 { 246 int fd; 247 const char *expandedname; 248 int oflags = O_RDONLY | O_CLOEXEC; 249 250 if (verifyflag) 251 oflags |= O_VERIFY; 252 253 expandedname = expandstr(name); 254 if (expandedname == NULL) 255 return; 256 INTOFF; 257 if ((fd = open(expandedname, oflags)) >= 0) 258 setinputfd(fd, 1); 259 INTON; 260 if (fd < 0) 261 return; 262 cmdloop(0); 263 popfile(); 264 } 265 266 267 268 /* 269 * Read a file containing shell functions. 270 */ 271 272 void 273 readcmdfile(const char *name, int verify) 274 { 275 setinputfile(name, 1, verify); 276 cmdloop(0); 277 popfile(); 278 } 279 280 281 282 /* 283 * Take commands from a file. To be compatible we should do a path 284 * search for the file, which is necessary to find sub-commands. 285 */ 286 287 288 static char * 289 find_dot_file(char *basename) 290 { 291 char *fullname; 292 const char *opt; 293 const char *path = pathval(); 294 struct stat statb; 295 296 /* don't try this for absolute or relative paths */ 297 if( strchr(basename, '/')) 298 return basename; 299 300 while ((fullname = padvance(&path, &opt, basename)) != NULL) { 301 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) { 302 /* 303 * Don't bother freeing here, since it will 304 * be freed by the caller. 305 */ 306 return fullname; 307 } 308 stunalloc(fullname); 309 } 310 return basename; 311 } 312 313 int 314 dotcmd(int argc, char **argv) 315 { 316 char *filename, *fullname; 317 318 if (argc < 2) 319 error("missing filename"); 320 321 exitstatus = 0; 322 323 /* 324 * Because we have historically not supported any options, 325 * only treat "--" specially. 326 */ 327 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1]; 328 329 fullname = find_dot_file(filename); 330 setinputfile(fullname, 1, -1 /* verify */); 331 commandname = fullname; 332 cmdloop(0); 333 popfile(); 334 return exitstatus; 335 } 336 337 338 int 339 exitcmd(int argc, char **argv) 340 { 341 if (stoppedjobs()) 342 return 0; 343 if (argc > 1) 344 exitshell(number(argv[1])); 345 else 346 exitshell_savedstatus(); 347 } 348