main.c revision 1.11
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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static char copyright[] = 39 "@(#) Copyright (c) 1991, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 static char sccsid[] = "@(#)main.c 8.1 (Berkeley) 5/31/93"; 45 #endif /* not lint */ 46 47 #include <stdio.h> 48 #include <signal.h> 49 #include <sys/stat.h> 50 #include <fcntl.h> 51 #include "shell.h" 52 #include "main.h" 53 #include "mail.h" 54 #include "options.h" 55 #include "output.h" 56 #include "parser.h" 57 #include "nodes.h" 58 #include "eval.h" 59 #include "jobs.h" 60 #include "input.h" 61 #include "trap.h" 62 #include "var.h" 63 #include "memalloc.h" 64 #include "error.h" 65 #include "init.h" 66 #include "mystring.h" 67 #include "exec.h" 68 69 #define PROFILE 0 70 71 int rootpid; 72 int rootshell; 73 STATIC union node *curcmd; 74 STATIC union node *prevcmd; 75 extern int errno; 76 #if PROFILE 77 short profile_buf[16384]; 78 extern int etext(); 79 #endif 80 81 #ifdef __STDC__ 82 STATIC void read_profile(char *); 83 char *getenv(char *); 84 #else 85 STATIC void read_profile(); 86 char *getenv(); 87 #endif 88 89 90 /* 91 * Main routine. We initialize things, parse the arguments, execute 92 * profiles if we're a login shell, and then call cmdloop to execute 93 * commands. The setjmp call sets up the location to jump to when an 94 * exception occurs. When an exception occurs the variable "state" 95 * is used to figure out how far we had gotten. 96 */ 97 98 main(argc, argv) char **argv; { 99 struct jmploc jmploc; 100 struct stackmark smark; 101 volatile int state; 102 char *shinit; 103 104 #if PROFILE 105 monitor(4, etext, profile_buf, sizeof profile_buf, 50); 106 #endif 107 state = 0; 108 if (setjmp(jmploc.loc)) { 109 /* 110 * When a shell procedure is executed, we raise the 111 * exception EXSHELLPROC to clean up before executing 112 * the shell procedure. 113 */ 114 if (exception == EXSHELLPROC) { 115 rootpid = getpid(); 116 rootshell = 1; 117 minusc = NULL; 118 state = 3; 119 } else if (state == 0 || iflag == 0 || ! rootshell) 120 exitshell(2); 121 reset(); 122 if (exception == EXINT 123 #if ATTY 124 && (! attyset() || equal(termval(), "emacs")) 125 #endif 126 ) { 127 out2c('\n'); 128 flushout(&errout); 129 } 130 popstackmark(&smark); 131 FORCEINTON; /* enable interrupts */ 132 if (state == 1) 133 goto state1; 134 else if (state == 2) 135 goto state2; 136 else if (state == 3) 137 goto state3; 138 else 139 goto state4; 140 } 141 handler = &jmploc; 142 #ifdef DEBUG 143 opentrace(); 144 trputs("Shell args: "); trargs(argv); 145 #endif 146 rootpid = getpid(); 147 rootshell = 1; 148 init(); 149 setstackmark(&smark); 150 procargs(argc, argv); 151 if (argv[0] && argv[0][0] == '-') { 152 state = 1; 153 read_profile("/etc/profile"); 154 state1: 155 state = 2; 156 read_profile(".profile"); 157 } 158 state2: 159 state = 3; 160 if ((shinit = lookupvar("ENV")) != NULL && 161 *shinit != '\0') { 162 state = 3; 163 read_profile(shinit); 164 } 165 state3: 166 state = 4; 167 if (minusc) { 168 evalstring(minusc); 169 } 170 if (sflag || minusc == NULL) { 171 state4: /* XXX ??? - why isn't this before the "if" statement */ 172 cmdloop(1); 173 } 174 #if PROFILE 175 monitor(0); 176 #endif 177 exitshell(exitstatus); 178 } 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 void 187 cmdloop(top) { 188 union node *n; 189 struct stackmark smark; 190 int inter; 191 int numeof = 0; 192 193 TRACE(("cmdloop(%d) called\n", top)); 194 setstackmark(&smark); 195 for (;;) { 196 if (pendingsigs) 197 dotrap(); 198 inter = 0; 199 if (iflag && top) { 200 inter++; 201 showjobs(1); 202 chkmail(0); 203 flushout(&output); 204 } 205 n = parsecmd(inter); 206 /* showtree(n); DEBUG */ 207 if (n == NEOF) { 208 if (!top || numeof >= 50) 209 break; 210 if (!stoppedjobs()) { 211 if (!Iflag) 212 break; 213 out2str("\nUse \"exit\" to leave shell.\n"); 214 } 215 numeof++; 216 } else if (n != NULL && nflag == 0) { 217 job_warning = (job_warning == 2) ? 1 : 0; 218 numeof = 0; 219 evaltree(n, 0); 220 } 221 popstackmark(&smark); 222 } 223 popstackmark(&smark); /* unnecessary */ 224 } 225 226 227 228 /* 229 * Read /etc/profile or .profile. Return on error. 230 */ 231 232 STATIC void 233 read_profile(name) 234 char *name; 235 { 236 int fd; 237 238 INTOFF; 239 if ((fd = open(name, O_RDONLY)) >= 0) 240 setinputfd(fd, 1); 241 INTON; 242 if (fd < 0) 243 return; 244 cmdloop(0); 245 popfile(); 246 } 247 248 249 250 /* 251 * Read a file containing shell functions. 252 */ 253 254 void 255 readcmdfile(name) 256 char *name; 257 { 258 int fd; 259 260 INTOFF; 261 if ((fd = open(name, O_RDONLY)) >= 0) 262 setinputfd(fd, 1); 263 else 264 error("Can't open %s", name); 265 INTON; 266 cmdloop(0); 267 popfile(); 268 } 269 270 271 272 /* 273 * Take commands from a file. To be compatable we should do a path 274 * search for the file, which is necessary to find sub-commands. 275 */ 276 277 278 static char * 279 find_dot_file(basename) char *basename; { 280 static char localname[FILENAME_MAX+1]; 281 char *fullname; 282 char *path = pathval(); 283 struct stat statb; 284 285 /* don't try this for absolute or relative paths */ 286 if( strchr(basename, '/')) 287 return basename; 288 289 while ((fullname = padvance(&path, basename)) != NULL) { 290 strcpy(localname, fullname); 291 stunalloc(fullname); 292 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) 293 return localname; 294 } 295 return basename; 296 } 297 298 dotcmd(argc, argv) char **argv; { 299 exitstatus = 0; 300 if (argc >= 2) { /* That's what SVR2 does */ 301 char *fullname = find_dot_file(argv[1]); 302 setinputfile(fullname, 1); 303 commandname = fullname; 304 cmdloop(0); 305 popfile(); 306 } 307 return exitstatus; 308 } 309 310 311 exitcmd(argc, argv) char **argv; { 312 if (stoppedjobs()) 313 return; 314 if (argc > 1) 315 exitstatus = number(argv[1]); 316 exitshell(exitstatus); 317 } 318 319 320 #ifdef notdef 321 /* 322 * Should never be called. 323 */ 324 325 void 326 exit(exitstatus) { 327 _exit(exitstatus); 328 } 329 #endif 330
Indexes created Wed Sep 24 05:09:52 GMT 2025