1 /* $NetBSD: main.c,v 1.67 2016/05/09 21:03:10 kre Exp $ */ 2 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 <sys/cdefs.h> 36 #ifndef lint 37 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\ 38 The Regents of the University of California. All rights reserved."); 39 #endif /* not lint */ 40 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)main.c 8.7 (Berkeley) 7/19/95"; 44 #else 45 __RCSID("$NetBSD: main.c,v 1.67 2016/05/09 21:03:10 kre Exp $"); 46 #endif 47 #endif /* not lint */ 48 49 #include <errno.h> 50 #include <stdio.h> 51 #include <signal.h> 52 #include <sys/stat.h> 53 #include <unistd.h> 54 #include <stdlib.h> 55 #include <locale.h> 56 #include <fcntl.h> 57 58 59 #include "shell.h" 60 #include "main.h" 61 #include "mail.h" 62 #include "options.h" 63 #include "builtins.h" 64 #include "output.h" 65 #include "parser.h" 66 #include "nodes.h" 67 #include "expand.h" 68 #include "eval.h" 69 #include "jobs.h" 70 #include "input.h" 71 #include "trap.h" 72 #include "var.h" 73 #include "show.h" 74 #include "memalloc.h" 75 #include "error.h" 76 #include "init.h" 77 #include "mystring.h" 78 #include "exec.h" 79 #include "cd.h" 80 81 #define PROFILE 0 82 83 int rootpid; 84 int rootshell; 85 #if PROFILE 86 short profile_buf[16384]; 87 extern int etext(); 88 #endif 89 90 STATIC void read_profile(const char *); 91 int main(int, char **); 92 93 /* 94 * Main routine. We initialize things, parse the arguments, execute 95 * profiles if we're a login shell, and then call cmdloop to execute 96 * commands. The setjmp call sets up the location to jump to when an 97 * exception occurs. When an exception occurs the variable "state" 98 * is used to figure out how far we had gotten. 99 */ 100 101 int 102 main(int argc, char **argv) 103 { 104 struct jmploc jmploc; 105 struct stackmark smark; 106 volatile int state; 107 char *shinit; 108 uid_t uid; 109 gid_t gid; 110 111 uid = getuid(); 112 gid = getgid(); 113 114 setlocale(LC_ALL, ""); 115 116 posix = getenv("POSIXLY_CORRECT") != NULL; 117 #if PROFILE 118 monitor(4, etext, profile_buf, sizeof profile_buf, 50); 119 #endif 120 state = 0; 121 if (setjmp(jmploc.loc)) { 122 /* 123 * When a shell procedure is executed, we raise the 124 * exception EXSHELLPROC to clean up before executing 125 * the shell procedure. 126 */ 127 switch (exception) { 128 case EXSHELLPROC: 129 rootpid = getpid(); 130 rootshell = 1; 131 minusc = NULL; 132 state = 3; 133 break; 134 135 case EXEXEC: 136 exitstatus = exerrno; 137 break; 138 139 case EXERROR: 140 exitstatus = 2; 141 break; 142 143 default: 144 break; 145 } 146 147 if (exception != EXSHELLPROC) { 148 if (state == 0 || iflag == 0 || ! rootshell) 149 exitshell(exitstatus); 150 } 151 reset(); 152 if (exception == EXINT) { 153 out2c('\n'); 154 flushout(&errout); 155 } 156 popstackmark(&smark); 157 FORCEINTON; /* enable interrupts */ 158 if (state == 1) 159 goto state1; 160 else if (state == 2) 161 goto state2; 162 else if (state == 3) 163 goto state3; 164 else 165 goto state4; 166 } 167 handler = &jmploc; 168 #ifdef DEBUG 169 #if DEBUG == 2 170 debug = 1; 171 #endif 172 opentrace(); 173 trputs("Shell args: "); trargs(argv); 174 #endif 175 rootpid = getpid(); 176 rootshell = 1; 177 init(); 178 initpwd(); 179 setstackmark(&smark); 180 procargs(argc, argv); 181 182 /* 183 * Limit bogus system(3) or popen(3) calls in setuid binaries, 184 * by requiring the -p flag 185 */ 186 if (!pflag && (uid != geteuid() || gid != getegid())) { 187 setuid(uid); 188 setgid(gid); 189 /* PS1 might need to be changed accordingly. */ 190 choose_ps1(); 191 } 192 193 if (argv[0] && argv[0][0] == '-') { 194 state = 1; 195 read_profile("/etc/profile"); 196 state1: 197 state = 2; 198 read_profile(".profile"); 199 } 200 state2: 201 state = 3; 202 if ((iflag || !posix) && 203 getuid() == geteuid() && getgid() == getegid()) { 204 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') { 205 state = 3; 206 read_profile(shinit); 207 } 208 } 209 state3: 210 state = 4; 211 if (sflag == 0 || minusc) { 212 static int sigs[] = { 213 SIGINT, SIGQUIT, SIGHUP, 214 #ifdef SIGTSTP 215 SIGTSTP, 216 #endif 217 SIGPIPE 218 }; 219 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0])) 220 size_t i; 221 222 for (i = 0; i < SIGSSIZE; i++) 223 setsignal(sigs[i], 0); 224 } 225 226 if (minusc) 227 evalstring(minusc, 0); 228 229 if (sflag || minusc == NULL) { 230 state4: /* XXX ??? - why isn't this before the "if" statement */ 231 cmdloop(1); 232 } 233 #if PROFILE 234 monitor(0); 235 #endif 236 exitshell(exitstatus); 237 /* NOTREACHED */ 238 } 239 240 241 /* 242 * Read and execute commands. "Top" is nonzero for the top level command 243 * loop; it turns on prompting if the shell is interactive. 244 */ 245 246 void 247 cmdloop(int top) 248 { 249 union node *n; 250 struct stackmark smark; 251 int inter; 252 int numeof = 0; 253 enum skipstate skip; 254 255 TRACE(("cmdloop(%d) called\n", top)); 256 setstackmark(&smark); 257 for (;;) { 258 if (pendingsigs) 259 dotrap(); 260 inter = 0; 261 if (iflag == 1 && top) { 262 inter = 1; 263 showjobs(out2, SHOW_CHANGED); 264 chkmail(0); 265 flushout(&errout); 266 nflag = 0; 267 } 268 n = parsecmd(inter); 269 TRACE(("cmdloop: "); showtree(n)); 270 /* showtree(n); DEBUG */ 271 if (n == NEOF) { 272 if (!top || numeof >= 50) 273 break; 274 if (nflag) 275 break; 276 if (!stoppedjobs()) { 277 if (!iflag || !Iflag) 278 break; 279 out2str("\nUse \"exit\" to leave shell.\n"); 280 } 281 numeof++; 282 } else if (n != NULL && nflag == 0) { 283 job_warning = (job_warning == 2) ? 1 : 0; 284 numeof = 0; 285 evaltree(n, EV_MORE); 286 } 287 popstackmark(&smark); 288 setstackmark(&smark); 289 290 /* 291 * Any SKIP* can occur here! SKIP(FUNC|BREAK|CONT) occur when 292 * a dotcmd is in a loop or a function body and appropriate 293 * built-ins occurs in file scope in the sourced file. Values 294 * other than SKIPFILE are reset by the appropriate eval*() 295 * that contained the dotcmd() call. 296 */ 297 skip = current_skipstate(); 298 if (skip != SKIPNONE) { 299 if (skip == SKIPFILE) 300 stop_skipping(); 301 break; 302 } 303 } 304 popstackmark(&smark); 305 } 306 307 308 309 /* 310 * Read /etc/profile or .profile. Return on error. 311 */ 312 313 STATIC void 314 read_profile(const char *name) 315 { 316 int fd; 317 int xflag_set = 0; 318 int vflag_set = 0; 319 320 INTOFF; 321 if ((fd = open(name, O_RDONLY)) >= 0) 322 setinputfd(fd, 1); 323 INTON; 324 if (fd < 0) 325 return; 326 /* -q turns off -x and -v just when executing init files */ 327 if (qflag) { 328 if (xflag) 329 xflag = 0, xflag_set = 1; 330 if (vflag) 331 vflag = 0, vflag_set = 1; 332 } 333 cmdloop(0); 334 if (qflag) { 335 if (xflag_set) 336 xflag = 1; 337 if (vflag_set) 338 vflag = 1; 339 } 340 popfile(); 341 } 342 343 344 345 /* 346 * Read a file containing shell functions. 347 */ 348 349 void 350 readcmdfile(char *name) 351 { 352 int fd; 353 354 INTOFF; 355 if ((fd = open(name, O_RDONLY)) >= 0) 356 setinputfd(fd, 1); 357 else 358 error("Can't open %s", name); 359 INTON; 360 cmdloop(0); 361 popfile(); 362 } 363 364 365 366 int 367 exitcmd(int argc, char **argv) 368 { 369 if (stoppedjobs()) 370 return 0; 371 if (argc > 1) 372 exitstatus = number(argv[1]); 373 exitshell(exitstatus); 374 /* NOTREACHED */ 375 } 376