main.c revision 211349
1/*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#ifndef lint 34static char const copyright[] = 35"@(#) Copyright (c) 1991, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37#endif /* not lint */ 38 39#ifndef lint 40#if 0 41static char sccsid[] = "@(#)main.c 8.6 (Berkeley) 5/28/95"; 42#endif 43#endif /* not lint */ 44#include <sys/cdefs.h> 45__FBSDID("$FreeBSD: head/bin/sh/main.c 211349 2010-08-15 21:06:53Z jilles $"); 46 47#include <stdio.h> 48#include <signal.h> 49#include <sys/stat.h> 50#include <unistd.h> 51#include <fcntl.h> 52#include <locale.h> 53#include <errno.h> 54 55#include "shell.h" 56#include "main.h" 57#include "mail.h" 58#include "options.h" 59#include "output.h" 60#include "parser.h" 61#include "nodes.h" 62#include "expand.h" 63#include "eval.h" 64#include "jobs.h" 65#include "input.h" 66#include "trap.h" 67#include "var.h" 68#include "show.h" 69#include "memalloc.h" 70#include "error.h" 71#include "init.h" 72#include "mystring.h" 73#include "exec.h" 74#include "cd.h" 75 76int rootpid; 77int rootshell; 78struct jmploc main_handler; 79 80STATIC void read_profile(const char *); 81STATIC 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 91int 92main(int argc, char *argv[]) 93{ 94 struct stackmark smark; 95 volatile int state; 96 char *shinit; 97 98 (void) setlocale(LC_ALL, ""); 99 state = 0; 100 if (setjmp(main_handler.loc)) { 101 /* 102 * When a shell procedure is executed, we raise the 103 * exception EXSHELLPROC to clean up before executing 104 * the shell procedure. 105 */ 106 switch (exception) { 107 case EXSHELLPROC: 108 rootpid = getpid(); 109 rootshell = 1; 110 minusc = NULL; 111 state = 3; 112 break; 113 114 case EXEXEC: 115 exitstatus = exerrno; 116 break; 117 118 case EXERROR: 119 exitstatus = 2; 120 break; 121 122 default: 123 break; 124 } 125 126 if (exception != EXSHELLPROC) { 127 if (state == 0 || iflag == 0 || ! rootshell) 128 exitshell(exitstatus); 129 } 130 reset(); 131 if (exception == EXINT) { 132 out2c('\n'); 133 flushout(&errout); 134 } 135 popstackmark(&smark); 136 FORCEINTON; /* enable interrupts */ 137 if (state == 1) 138 goto state1; 139 else if (state == 2) 140 goto state2; 141 else if (state == 3) 142 goto state3; 143 else 144 goto state4; 145 } 146 handler = &main_handler; 147#ifdef DEBUG 148 opentrace(); 149 trputs("Shell args: "); trargs(argv); 150#endif 151 rootpid = getpid(); 152 rootshell = 1; 153 init(); 154 setstackmark(&smark); 155 procargs(argc, argv); 156 pwd_init(iflag); 157 if (iflag) 158 chkmail(1); 159 if (argv[0] && argv[0][0] == '-') { 160 state = 1; 161 read_profile("/etc/profile"); 162state1: 163 state = 2; 164 if (privileged == 0) 165 read_profile(".profile"); 166 else 167 read_profile("/etc/suid_profile"); 168 } 169state2: 170 state = 3; 171 if (!privileged && iflag) { 172 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') { 173 state = 3; 174 read_profile(shinit); 175 } 176 } 177state3: 178 state = 4; 179 if (minusc) { 180 evalstring(minusc, sflag ? 0 : EV_EXIT); 181 } 182 if (sflag || minusc == NULL) { 183state4: /* XXX ??? - why isn't this before the "if" statement */ 184 cmdloop(1); 185 } 186 exitshell(exitstatus); 187 /*NOTREACHED*/ 188 return 0; 189} 190 191 192/* 193 * Read and execute commands. "Top" is nonzero for the top level command 194 * loop; it turns on prompting if the shell is interactive. 195 */ 196 197void 198cmdloop(int top) 199{ 200 union node *n; 201 struct stackmark smark; 202 int inter; 203 int numeof = 0; 204 205 TRACE(("cmdloop(%d) called\n", top)); 206 setstackmark(&smark); 207 for (;;) { 208 if (pendingsigs) 209 dotrap(); 210 inter = 0; 211 if (iflag && top) { 212 inter++; 213 showjobs(1, SHOWJOBS_DEFAULT); 214 chkmail(0); 215 flushout(&output); 216 } 217 n = parsecmd(inter); 218 /* showtree(n); DEBUG */ 219 if (n == NEOF) { 220 if (!top || numeof >= 50) 221 break; 222 if (!stoppedjobs()) { 223 if (!Iflag) 224 break; 225 out2fmt_flush("\nUse \"exit\" to leave shell.\n"); 226 } 227 numeof++; 228 } else if (n != NULL && nflag == 0) { 229 job_warning = (job_warning == 2) ? 1 : 0; 230 numeof = 0; 231 evaltree(n, 0); 232 } 233 popstackmark(&smark); 234 setstackmark(&smark); 235 if (evalskip != 0) { 236 if (evalskip == SKIPFILE) 237 evalskip = 0; 238 break; 239 } 240 } 241 popstackmark(&smark); 242} 243 244 245 246/* 247 * Read /etc/profile or .profile. Return on error. 248 */ 249 250STATIC void 251read_profile(const char *name) 252{ 253 int fd; 254 255 INTOFF; 256 if ((fd = open(name, O_RDONLY)) >= 0) 257 setinputfd(fd, 1); 258 INTON; 259 if (fd < 0) 260 return; 261 cmdloop(0); 262 popfile(); 263} 264 265 266 267/* 268 * Read a file containing shell functions. 269 */ 270 271void 272readcmdfile(const char *name) 273{ 274 int fd; 275 276 INTOFF; 277 if ((fd = open(name, O_RDONLY)) >= 0) 278 setinputfd(fd, 1); 279 else 280 error("Can't open %s: %s", name, strerror(errno)); 281 INTON; 282 cmdloop(0); 283 popfile(); 284} 285 286 287 288/* 289 * Take commands from a file. To be compatible we should do a path 290 * search for the file, which is necessary to find sub-commands. 291 */ 292 293 294STATIC char * 295find_dot_file(char *basename) 296{ 297 static char localname[FILENAME_MAX+1]; 298 char *fullname; 299 const char *path = pathval(); 300 struct stat statb; 301 302 /* don't try this for absolute or relative paths */ 303 if( strchr(basename, '/')) 304 return basename; 305 306 while ((fullname = padvance(&path, basename)) != NULL) { 307 strcpy(localname, fullname); 308 stunalloc(fullname); 309 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) 310 return localname; 311 } 312 return basename; 313} 314 315int 316dotcmd(int argc, char **argv) 317{ 318 char *filename, *fullname; 319 320 if (argc < 2) 321 error("missing filename"); 322 323 exitstatus = 0; 324 325 /* 326 * Because we have historically not supported any options, 327 * only treat "--" specially. 328 */ 329 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1]; 330 331 fullname = find_dot_file(filename); 332 setinputfile(fullname, 1); 333 commandname = fullname; 334 cmdloop(0); 335 popfile(); 336 return exitstatus; 337} 338 339 340int 341exitcmd(int argc, char **argv) 342{ 343 if (stoppedjobs()) 344 return 0; 345 if (argc > 1) 346 exitstatus = number(argv[1]); 347 else 348 exitstatus = oexitstatus; 349 exitshell(exitstatus); 350 /*NOTREACHED*/ 351 return 0; 352} 353