main.c revision 221559
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 221559 2011-05-06 22:31:27Z 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; 79int localeisutf8; 80 81static void read_profile(const char *); 82static char *find_dot_file(char *); 83 84/* 85 * Main routine. We initialize things, parse the arguments, execute 86 * profiles if we're a login shell, and then call cmdloop to execute 87 * commands. The setjmp call sets up the location to jump to when an 88 * exception occurs. When an exception occurs the variable "state" 89 * is used to figure out how far we had gotten. 90 */ 91 92int 93main(int argc, char *argv[]) 94{ 95 struct stackmark smark; 96 volatile int state; 97 char *shinit; 98 99 (void) setlocale(LC_ALL, ""); 100 updatecharset(); 101 state = 0; 102 if (setjmp(main_handler.loc)) { 103 switch (exception) { 104 case EXEXEC: 105 exitstatus = exerrno; 106 break; 107 108 case EXERROR: 109 exitstatus = 2; 110 break; 111 112 default: 113 break; 114 } 115 116 if (state == 0 || iflag == 0 || ! rootshell || 117 exception == EXEXIT) 118 exitshell(exitstatus); 119 reset(); 120 if (exception == EXINT) 121 out2fmt_flush("\n"); 122 popstackmark(&smark); 123 FORCEINTON; /* enable interrupts */ 124 if (state == 1) 125 goto state1; 126 else if (state == 2) 127 goto state2; 128 else if (state == 3) 129 goto state3; 130 else 131 goto state4; 132 } 133 handler = &main_handler; 134#ifdef DEBUG 135 opentrace(); 136 trputs("Shell args: "); trargs(argv); 137#endif 138 rootpid = getpid(); 139 rootshell = 1; 140 init(); 141 setstackmark(&smark); 142 procargs(argc, argv); 143 pwd_init(iflag); 144 if (iflag) 145 chkmail(1); 146 if (argv[0] && argv[0][0] == '-') { 147 state = 1; 148 read_profile("/etc/profile"); 149state1: 150 state = 2; 151 if (privileged == 0) 152 read_profile(".profile"); 153 else 154 read_profile("/etc/suid_profile"); 155 } 156state2: 157 state = 3; 158 if (!privileged && iflag) { 159 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') { 160 state = 3; 161 read_profile(shinit); 162 } 163 } 164state3: 165 state = 4; 166 if (minusc) { 167 evalstring(minusc, sflag ? 0 : EV_EXIT); 168 } 169 if (sflag || minusc == NULL) { 170state4: /* XXX ??? - why isn't this before the "if" statement */ 171 cmdloop(1); 172 } 173 exitshell(exitstatus); 174 /*NOTREACHED*/ 175 return 0; 176} 177 178 179/* 180 * Read and execute commands. "Top" is nonzero for the top level command 181 * loop; it turns on prompting if the shell is interactive. 182 */ 183 184void 185cmdloop(int top) 186{ 187 union node *n; 188 struct stackmark smark; 189 int inter; 190 int numeof = 0; 191 192 TRACE(("cmdloop(%d) called\n", top)); 193 setstackmark(&smark); 194 for (;;) { 195 if (pendingsigs) 196 dotrap(); 197 inter = 0; 198 if (iflag && top) { 199 inter++; 200 showjobs(1, SHOWJOBS_DEFAULT); 201 chkmail(0); 202 flushout(&output); 203 } 204 n = parsecmd(inter); 205 /* showtree(n); DEBUG */ 206 if (n == NEOF) { 207 if (!top || numeof >= 50) 208 break; 209 if (!stoppedjobs()) { 210 if (!Iflag) 211 break; 212 out2fmt_flush("\nUse \"exit\" to leave shell.\n"); 213 } 214 numeof++; 215 } else if (n != NULL && nflag == 0) { 216 job_warning = (job_warning == 2) ? 1 : 0; 217 numeof = 0; 218 evaltree(n, 0); 219 } 220 popstackmark(&smark); 221 setstackmark(&smark); 222 if (evalskip != 0) { 223 if (evalskip == SKIPFILE) 224 evalskip = 0; 225 break; 226 } 227 } 228 popstackmark(&smark); 229} 230 231 232 233/* 234 * Read /etc/profile or .profile. Return on error. 235 */ 236 237static void 238read_profile(const char *name) 239{ 240 int fd; 241 242 INTOFF; 243 if ((fd = open(name, O_RDONLY)) >= 0) 244 setinputfd(fd, 1); 245 INTON; 246 if (fd < 0) 247 return; 248 cmdloop(0); 249 popfile(); 250} 251 252 253 254/* 255 * Read a file containing shell functions. 256 */ 257 258void 259readcmdfile(const char *name) 260{ 261 int fd; 262 263 INTOFF; 264 if ((fd = open(name, O_RDONLY)) >= 0) 265 setinputfd(fd, 1); 266 else 267 error("Can't open %s: %s", name, strerror(errno)); 268 INTON; 269 cmdloop(0); 270 popfile(); 271} 272 273 274 275/* 276 * Take commands from a file. To be compatible we should do a path 277 * search for the file, which is necessary to find sub-commands. 278 */ 279 280 281static char * 282find_dot_file(char *basename) 283{ 284 static char localname[FILENAME_MAX+1]; 285 char *fullname; 286 const char *path = pathval(); 287 struct stat statb; 288 289 /* don't try this for absolute or relative paths */ 290 if( strchr(basename, '/')) 291 return basename; 292 293 while ((fullname = padvance(&path, basename)) != NULL) { 294 strcpy(localname, fullname); 295 stunalloc(fullname); 296 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) 297 return localname; 298 } 299 return basename; 300} 301 302int 303dotcmd(int argc, char **argv) 304{ 305 char *filename, *fullname; 306 307 if (argc < 2) 308 error("missing filename"); 309 310 exitstatus = 0; 311 312 /* 313 * Because we have historically not supported any options, 314 * only treat "--" specially. 315 */ 316 filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1]; 317 318 fullname = find_dot_file(filename); 319 setinputfile(fullname, 1); 320 commandname = fullname; 321 cmdloop(0); 322 popfile(); 323 return exitstatus; 324} 325 326 327int 328exitcmd(int argc, char **argv) 329{ 330 if (stoppedjobs()) 331 return 0; 332 if (argc > 1) 333 exitshell(number(argv[1])); 334 else 335 exitshell_savedstatus(); 336} 337