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 #if 0 39 static char sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95"; 40 #endif 41 #endif /* not lint */ 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <sys/types.h> 46 #include <sys/stat.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 #include <errno.h> 51 #include <limits.h> 52 53 /* 54 * The cd and pwd commands. 55 */ 56 57 #include "shell.h" 58 #include "var.h" 59 #include "nodes.h" /* for jobs.h */ 60 #include "jobs.h" 61 #include "options.h" 62 #include "output.h" 63 #include "memalloc.h" 64 #include "error.h" 65 #include "exec.h" 66 #include "redir.h" 67 #include "mystring.h" 68 #include "show.h" 69 #include "cd.h" 70 71 STATIC int cdlogical(char *); 72 STATIC int cdphysical(char *); 73 STATIC int docd(char *, int, int); 74 STATIC char *getcomponent(void); 75 STATIC int updatepwd(char *); 76 77 STATIC char *curdir = NULL; /* current working directory */ 78 STATIC char *prevdir; /* previous working directory */ 79 STATIC char *cdcomppath; 80 81 int 82 cdcmd(int argc, char **argv) 83 { 84 char *dest; 85 char *path; 86 char *p; 87 struct stat statb; 88 int ch, phys, print = 0; 89 90 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 91 phys = Pflag; 92 while ((ch = getopt(argc, argv, "LP")) != -1) { 93 switch (ch) { 94 case 'L': 95 phys = 0; 96 break; 97 case 'P': 98 phys = 1; 99 break; 100 default: 101 error("unknown option: -%c", optopt); 102 break; 103 } 104 } 105 argc -= optind; 106 argv += optind; 107 108 if (argc > 1) 109 error("too many arguments"); 110 111 if ((dest = *argv) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 112 error("HOME not set"); 113 if (*dest == '\0') 114 dest = "."; 115 if (dest[0] == '-' && dest[1] == '\0') { 116 dest = prevdir ? prevdir : curdir; 117 if (dest) 118 print = 1; 119 else 120 dest = "."; 121 } 122 if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL) 123 path = nullstr; 124 while ((p = padvance(&path, dest)) != NULL) { 125 if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { 126 if (!print) { 127 /* 128 * XXX - rethink 129 */ 130 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 131 p += 2; 132 print = strcmp(p, dest); 133 } 134 if (docd(p, print, phys) >= 0) 135 return 0; 136 } 137 } 138 error("can't cd to %s", dest); 139 /*NOTREACHED*/ 140 return 0; 141 } 142 143 144 /* 145 * Actually change the directory. In an interactive shell, print the 146 * directory name if "print" is nonzero. 147 */ 148 STATIC int 149 docd(char *dest, int print, int phys) 150 { 151 152 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 153 154 /* If logical cd fails, fall back to physical. */ 155 if ((phys || cdlogical(dest) < 0) && cdphysical(dest) < 0) 156 return (-1); 157 158 if (print && iflag && curdir) 159 out1fmt("%s\n", curdir); 160 161 return 0; 162 } 163 164 STATIC int 165 cdlogical(char *dest) 166 { 167 char *p; 168 char *q; 169 char *component; 170 struct stat statb; 171 int first; 172 int badstat; 173 174 /* 175 * Check each component of the path. If we find a symlink or 176 * something we can't stat, clear curdir to force a getcwd() 177 * next time we get the value of the current directory. 178 */ 179 badstat = 0; 180 cdcomppath = stalloc(strlen(dest) + 1); 181 scopy(dest, cdcomppath); 182 STARTSTACKSTR(p); 183 if (*dest == '/') { 184 STPUTC('/', p); 185 cdcomppath++; 186 } 187 first = 1; 188 while ((q = getcomponent()) != NULL) { 189 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 190 continue; 191 if (! first) 192 STPUTC('/', p); 193 first = 0; 194 component = q; 195 while (*q) 196 STPUTC(*q++, p); 197 if (equal(component, "..")) 198 continue; 199 STACKSTRNUL(p); 200 if (lstat(stackblock(), &statb) < 0) { 201 badstat = 1; 202 break; 203 } 204 } 205 206 INTOFF; 207 if (updatepwd(badstat ? NULL : dest) < 0 || chdir(curdir) < 0) { 208 INTON; 209 return (-1); 210 } 211 INTON; 212 return (0); 213 } 214 215 STATIC int 216 cdphysical(char *dest) 217 { 218 219 INTOFF; 220 if (chdir(dest) < 0 || updatepwd(NULL) < 0) { 221 INTON; 222 return (-1); 223 } 224 INTON; 225 return (0); 226 } 227 228 /* 229 * Get the next component of the path name pointed to by cdcomppath. 230 * This routine overwrites the string pointed to by cdcomppath. 231 */ 232 STATIC char * 233 getcomponent(void) 234 { 235 char *p; 236 char *start; 237 238 if ((p = cdcomppath) == NULL) 239 return NULL; 240 start = cdcomppath; 241 while (*p != '/' && *p != '\0') 242 p++; 243 if (*p == '\0') { 244 cdcomppath = NULL; 245 } else { 246 *p++ = '\0'; 247 cdcomppath = p; 248 } 249 return start; 250 } 251 252 253 /* 254 * Update curdir (the name of the current directory) in response to a 255 * cd command. We also call hashcd to let the routines in exec.c know 256 * that the current directory has changed. 257 */ 258 STATIC int 259 updatepwd(char *dir) 260 { 261 char *new; 262 char *p; 263 264 hashcd(); /* update command hash table */ 265 266 /* 267 * If our argument is NULL, we don't know the current directory 268 * any more because we traversed a symbolic link or something 269 * we couldn't stat(). 270 */ 271 if (dir == NULL || curdir == NULL) { 272 if (prevdir) 273 ckfree(prevdir); 274 INTOFF; 275 prevdir = curdir; 276 curdir = NULL; 277 if (getpwd() == NULL) { 278 INTON; 279 return (-1); 280 } 281 setvar("PWD", curdir, VEXPORT); 282 setvar("OLDPWD", prevdir, VEXPORT); 283 INTON; 284 return (0); 285 } 286 cdcomppath = stalloc(strlen(dir) + 1); 287 scopy(dir, cdcomppath); 288 STARTSTACKSTR(new); 289 if (*dir != '/') { 290 p = curdir; 291 while (*p) 292 STPUTC(*p++, new); 293 if (p[-1] == '/') 294 STUNPUTC(new); 295 } 296 while ((p = getcomponent()) != NULL) { 297 if (equal(p, "..")) { 298 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 299 } else if (*p != '\0' && ! equal(p, ".")) { 300 STPUTC('/', new); 301 while (*p) 302 STPUTC(*p++, new); 303 } 304 } 305 if (new == stackblock()) 306 STPUTC('/', new); 307 STACKSTRNUL(new); 308 INTOFF; 309 if (prevdir) 310 ckfree(prevdir); 311 prevdir = curdir; 312 curdir = savestr(stackblock()); 313 setvar("PWD", curdir, VEXPORT); 314 setvar("OLDPWD", prevdir, VEXPORT); 315 INTON; 316 317 return (0); 318 } 319 320 int 321 pwdcmd(int argc, char **argv) 322 { 323 char buf[PATH_MAX]; 324 int ch, phys; 325 326 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 327 phys = Pflag; 328 while ((ch = getopt(argc, argv, "LP")) != -1) { 329 switch (ch) { 330 case 'L': 331 phys = 0; 332 break; 333 case 'P': 334 phys = 1; 335 break; 336 default: 337 error("unknown option: -%c", optopt); 338 break; 339 } 340 } 341 argc -= optind; 342 argv += optind; 343 344 if (argc != 0) 345 error("too many arguments"); 346 347 if (!phys && getpwd()) { 348 out1str(curdir); 349 out1c('\n'); 350 } else { 351 if (getcwd(buf, sizeof(buf)) == NULL) 352 error(".: %s", strerror(errno)); 353 out1str(buf); 354 out1c('\n'); 355 } 356 357 return 0; 358 } 359 360 /* 361 * Find out what the current directory is. If we already know the current 362 * directory, this routine returns immediately. 363 */ 364 char * 365 getpwd(void) 366 { 367 char buf[PATH_MAX]; 368 369 if (curdir) 370 return curdir; 371 if (getcwd(buf, sizeof(buf)) == NULL) { 372 char *pwd = getenv("PWD"); 373 struct stat stdot, stpwd; 374 375 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 376 stat(pwd, &stpwd) != -1 && 377 stdot.st_dev == stpwd.st_dev && 378 stdot.st_ino == stpwd.st_ino) { 379 curdir = savestr(pwd); 380 return curdir; 381 } 382 return NULL; 383 } 384 curdir = savestr(buf); 385 386 return curdir; 387 } 388