1 /* $NetBSD: main.c,v 1.59 2015/05/26 21:35:15 christos 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 1.59 2015/05/26 21:35:15 christos 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 int posix; 86 #if PROFILE 87 short profile_buf[16384]; 88 extern int etext(); 89 #endif 90 91 STATIC void read_profile(const char *); 92 int main(int, char **); 93 94 /* 95 * Main routine. We initialize things, parse the arguments, execute 96 * profiles if we're a login shell, and then call cmdloop to execute 97 * commands. The setjmp call sets up the location to jump to when an 98 * exception occurs. When an exception occurs the variable "state" 99 * is used to figure out how far we had gotten. 100 */ 101 102 int 103 main(int argc, char **argv) 104 { 105 struct jmploc jmploc; 106 struct stackmark smark; 107 volatile int state; 108 char *shinit; 109 uid_t uid; 110 gid_t gid; 111 112 uid = getuid(); 113 gid = getgid(); 114 115 setlocale(LC_ALL, ""); 116 117 posix = getenv("POSIXLY_CORRECT") != NULL; 118 #if PROFILE 119 monitor(4, etext, profile_buf, sizeof profile_buf, 50); 120 #endif 121 state = 0; 122 if (setjmp(jmploc.loc)) { 123 /* 124 * When a shell procedure is executed, we raise the 125 * exception EXSHELLPROC to clean up before executing 126 * the shell procedure. 127 */ 128 switch (exception) { 129 case EXSHELLPROC: 130 rootpid = getpid(); 131 rootshell = 1; 132 minusc = NULL; 133 state = 3; 134 break; 135 136 case EXEXEC: 137 exitstatus = exerrno; 138 break; 139 140 case EXERROR: 141 exitstatus = 2; 142 break; 143 144 default: 145 break; 146 } 147 148 if (exception != EXSHELLPROC) { 149 if (state == 0 || iflag == 0 || ! rootshell) 150 exitshell(exitstatus); 151 } 152 reset(); 153 if (exception == EXINT 154 #if ATTY 155 && (! attyset() || equal(termval(), "emacs")) 156 #endif 157 ) { 158 out2c('\n'); 159 flushout(&errout); 160 } 161 popstackmark(&smark); 162 FORCEINTON; /* enable interrupts */ 163 if (state == 1) 164 goto state1; 165 else if (state == 2) 166 goto state2; 167 else if (state == 3) 168 goto state3; 169 else 170 goto state4; 171 } 172 handler = &jmploc; 173 #ifdef DEBUG 174 #if DEBUG == 2 175 debug = 1; 176 #endif 177 opentrace(); 178 trputs("Shell args: "); trargs(argv); 179 #endif 180 rootpid = getpid(); 181 rootshell = 1; 182 init(); 183 initpwd(); 184 setstackmark(&smark); 185 procargs(argc, argv); 186 187 /* 188 * Limit bogus system(3) or popen(3) calls in setuid binaries, 189 * by requiring the -p flag 190 */ 191 if (!pflag && (uid != geteuid() || gid != getegid())) { 192 setuid(uid); 193 setgid(gid); 194 /* PS1 might need to be changed accordingly. */ 195 choose_ps1(); 196 } 197 198 if (argv[0] && argv[0][0] == '-') { 199 state = 1; 200 read_profile("/etc/profile"); 201 state1: 202 state = 2; 203 read_profile(".profile"); 204 } 205 state2: 206 state = 3; 207 if ((iflag || !posix) && 208 getuid() == geteuid() && getgid() == getegid()) { 209 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') { 210 state = 3; 211 read_profile(shinit); 212 } 213 } 214 state3: 215 state = 4; 216 if (sflag == 0 || minusc) { 217 static int sigs[] = { 218 SIGINT, SIGQUIT, SIGHUP, 219 #ifdef SIGTSTP 220 SIGTSTP, 221 #endif 222 SIGPIPE 223 }; 224 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0])) 225 size_t i; 226 227 for (i = 0; i < SIGSSIZE; i++) 228 setsignal(sigs[i], 0); 229 } 230 231 if (minusc) 232 evalstring(minusc, 0); 233 234 if (sflag || minusc == NULL) { 235 state4: /* XXX ??? - why isn't this before the "if" statement */ 236 cmdloop(1); 237 } 238 #if PROFILE 239 monitor(0); 240 #endif 241 exitshell(exitstatus); 242 /* NOTREACHED */ 243 } 244 245 246 /* 247 * Read and execute commands. "Top" is nonzero for the top level command 248 * loop; it turns on prompting if the shell is interactive. 249 */ 250 251 void 252 cmdloop(int top) 253 { 254 union node *n; 255 struct stackmark smark; 256 int inter; 257 int numeof = 0; 258 enum skipstate skip; 259 260 TRACE(("cmdloop(%d) called\n", top)); 261 setstackmark(&smark); 262 for (;;) { 263 if (pendingsigs) 264 dotrap(); 265 inter = 0; 266 if (iflag == 1 && top) { 267 inter = 1; 268 showjobs(out2, SHOW_CHANGED); 269 chkmail(0); 270 flushout(&errout); 271 } 272 n = parsecmd(inter); 273 /* showtree(n); DEBUG */ 274 if (n == NEOF) { 275 if (!top || numeof >= 50) 276 break; 277 if (!stoppedjobs()) { 278 if (!Iflag) 279 break; 280 out2str("\nUse \"exit\" to leave shell.\n"); 281 } 282 numeof++; 283 } else if (n != NULL && nflag == 0) { 284 job_warning = (job_warning == 2) ? 1 : 0; 285 numeof = 0; 286 evaltree(n, 0); 287 } 288 popstackmark(&smark); 289 setstackmark(&smark); 290 291 /* 292 * Any SKIP* can occur here! SKIP(FUNC|BREAK|CONT) occur when 293 * a dotcmd is in a loop or a function body and appropriate 294 * built-ins occurs in file scope in the sourced file. Values 295 * other than SKIPFILE are reset by the appropriate eval*() 296 * that contained the dotcmd() call. 297 */ 298 skip = current_skipstate(); 299 if (skip != SKIPNONE) { 300 if (skip == SKIPFILE) 301 stop_skipping(); 302 break; 303 } 304 } 305 popstackmark(&smark); 306 } 307 308 309 310 /* 311 * Read /etc/profile or .profile. Return on error. 312 */ 313 314 STATIC void 315 read_profile(const char *name) 316 { 317 int fd; 318 int xflag_set = 0; 319 int vflag_set = 0; 320 321 INTOFF; 322 if ((fd = open(name, O_RDONLY)) >= 0) 323 setinputfd(fd, 1); 324 INTON; 325 if (fd < 0) 326 return; 327 /* -q turns off -x and -v just when executing init files */ 328 if (qflag) { 329 if (xflag) 330 xflag = 0, xflag_set = 1; 331 if (vflag) 332 vflag = 0, vflag_set = 1; 333 } 334 cmdloop(0); 335 if (qflag) { 336 if (xflag_set) 337 xflag = 1; 338 if (vflag_set) 339 vflag = 1; 340 } 341 popfile(); 342 } 343 344 345 346 /* 347 * Read a file containing shell functions. 348 */ 349 350 void 351 readcmdfile(char *name) 352 { 353 int fd; 354 355 INTOFF; 356 if ((fd = open(name, O_RDONLY)) >= 0) 357 setinputfd(fd, 1); 358 else 359 error("Can't open %s", name); 360 INTON; 361 cmdloop(0); 362 popfile(); 363 } 364 365 366 367 int 368 exitcmd(int argc, char **argv) 369 { 370 if (stoppedjobs()) 371 return 0; 372 if (argc > 1) 373 exitstatus = number(argv[1]); 374 exitshell(exitstatus); 375 /* NOTREACHED */ 376 } 377