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 34 #if 0 35 static char sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <unistd.h> 46 #include <errno.h> 47 #include <limits.h> 48 49 /* 50 * The cd and pwd commands. 51 */ 52 53 #include "shell.h" 54 #include "var.h" 55 #include "nodes.h" /* for jobs.h */ 56 #include "jobs.h" 57 #include "options.h" 58 #include "output.h" 59 #include "memalloc.h" 60 #include "error.h" 61 #include "exec.h" 62 #include "redir.h" 63 #include "mystring.h" 64 #include "show.h" 65 #include "cd.h" 66 #include "builtins.h" 67 68 static int cdlogical(char *); 69 static int cdphysical(char *); 70 static int docd(char *, int, int); 71 static char *getcomponent(void); 72 static char *findcwd(char *); 73 static void updatepwd(char *); 74 static char *getpwd(void); 75 static char *getpwd2(void); 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 const char *dest; 85 const char *path; 86 char *p; 87 struct stat statb; 88 int ch, phys, print = 0, getcwderr = 0; 89 int rc; 90 int errno1 = ENOENT; 91 92 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 93 phys = Pflag; 94 while ((ch = getopt(argc, argv, "eLP")) != -1) { 95 switch (ch) { 96 case 'e': 97 getcwderr = 1; 98 break; 99 case 'L': 100 phys = 0; 101 break; 102 case 'P': 103 phys = 1; 104 break; 105 default: 106 error("unknown option: -%c", optopt); 107 break; 108 } 109 } 110 argc -= optind; 111 argv += optind; 112 113 if (argc > 1) 114 error("too many arguments"); 115 116 if ((dest = *argv) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 117 error("HOME not set"); 118 if (*dest == '\0') 119 dest = "."; 120 if (dest[0] == '-' && dest[1] == '\0') { 121 dest = prevdir ? prevdir : curdir; 122 if (dest) 123 print = 1; 124 else 125 dest = "."; 126 } 127 if (dest[0] == '/' || 128 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) || 129 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) || 130 (path = bltinlookup("CDPATH", 1)) == NULL) 131 path = nullstr; 132 while ((p = padvance(&path, dest)) != NULL) { 133 if (stat(p, &statb) < 0) { 134 if (errno != ENOENT) 135 errno1 = errno; 136 } else if (!S_ISDIR(statb.st_mode)) 137 errno1 = ENOTDIR; 138 else { 139 if (!print) { 140 /* 141 * XXX - rethink 142 */ 143 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 144 print = strcmp(p + 2, dest); 145 else 146 print = strcmp(p, dest); 147 } 148 rc = docd(p, print, phys); 149 if (rc >= 0) 150 return getcwderr ? rc : 0; 151 if (errno != ENOENT) 152 errno1 = errno; 153 } 154 } 155 error("%s: %s", dest, strerror(errno1)); 156 /*NOTREACHED*/ 157 return 0; 158 } 159 160 161 /* 162 * Actually change the directory. In an interactive shell, print the 163 * directory name if "print" is nonzero. 164 */ 165 static int 166 docd(char *dest, int print, int phys) 167 { 168 int rc; 169 170 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 171 172 /* If logical cd fails, fall back to physical. */ 173 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0) 174 return (-1); 175 176 if (print && iflag && curdir) 177 out1fmt("%s\n", curdir); 178 179 return (rc); 180 } 181 182 static int 183 cdlogical(char *dest) 184 { 185 char *p; 186 char *q; 187 char *component; 188 struct stat statb; 189 int first; 190 int badstat; 191 192 /* 193 * Check each component of the path. If we find a symlink or 194 * something we can't stat, clear curdir to force a getcwd() 195 * next time we get the value of the current directory. 196 */ 197 badstat = 0; 198 cdcomppath = stalloc(strlen(dest) + 1); 199 scopy(dest, cdcomppath); 200 STARTSTACKSTR(p); 201 if (*dest == '/') { 202 STPUTC('/', p); 203 cdcomppath++; 204 } 205 first = 1; 206 while ((q = getcomponent()) != NULL) { 207 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 208 continue; 209 if (! first) 210 STPUTC('/', p); 211 first = 0; 212 component = q; 213 STPUTS(q, p); 214 if (equal(component, "..")) 215 continue; 216 STACKSTRNUL(p); 217 if (lstat(stackblock(), &statb) < 0) { 218 badstat = 1; 219 break; 220 } 221 } 222 223 INTOFF; 224 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 225 INTON; 226 return (-1); 227 } 228 updatepwd(p); 229 INTON; 230 return (0); 231 } 232 233 static int 234 cdphysical(char *dest) 235 { 236 char *p; 237 int rc = 0; 238 239 INTOFF; 240 if (chdir(dest) < 0) { 241 INTON; 242 return (-1); 243 } 244 p = findcwd(NULL); 245 if (p == NULL) { 246 warning("warning: failed to get name of current directory"); 247 rc = 1; 248 } 249 updatepwd(p); 250 INTON; 251 return (rc); 252 } 253 254 /* 255 * Get the next component of the path name pointed to by cdcomppath. 256 * This routine overwrites the string pointed to by cdcomppath. 257 */ 258 static char * 259 getcomponent(void) 260 { 261 char *p; 262 char *start; 263 264 if ((p = cdcomppath) == NULL) 265 return NULL; 266 start = cdcomppath; 267 while (*p != '/' && *p != '\0') 268 p++; 269 if (*p == '\0') { 270 cdcomppath = NULL; 271 } else { 272 *p++ = '\0'; 273 cdcomppath = p; 274 } 275 return start; 276 } 277 278 279 static char * 280 findcwd(char *dir) 281 { 282 char *new; 283 char *p; 284 285 /* 286 * If our argument is NULL, we don't know the current directory 287 * any more because we traversed a symbolic link or something 288 * we couldn't stat(). 289 */ 290 if (dir == NULL || curdir == NULL) 291 return getpwd2(); 292 cdcomppath = stalloc(strlen(dir) + 1); 293 scopy(dir, cdcomppath); 294 STARTSTACKSTR(new); 295 if (*dir != '/') { 296 STPUTS(curdir, new); 297 if (STTOPC(new) == '/') 298 STUNPUTC(new); 299 } 300 while ((p = getcomponent()) != NULL) { 301 if (equal(p, "..")) { 302 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 303 } else if (*p != '\0' && ! equal(p, ".")) { 304 STPUTC('/', new); 305 STPUTS(p, new); 306 } 307 } 308 if (new == stackblock()) 309 STPUTC('/', new); 310 STACKSTRNUL(new); 311 return stackblock(); 312 } 313 314 /* 315 * Update curdir (the name of the current directory) in response to a 316 * cd command. We also call hashcd to let the routines in exec.c know 317 * that the current directory has changed. 318 */ 319 static void 320 updatepwd(char *dir) 321 { 322 hashcd(); /* update command hash table */ 323 324 if (prevdir) 325 ckfree(prevdir); 326 prevdir = curdir; 327 curdir = dir ? savestr(dir) : NULL; 328 setvar("PWD", curdir, VEXPORT); 329 setvar("OLDPWD", prevdir, VEXPORT); 330 } 331 332 int 333 pwdcmd(int argc, char **argv) 334 { 335 char *p; 336 int ch, phys; 337 338 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 339 phys = Pflag; 340 while ((ch = getopt(argc, argv, "LP")) != -1) { 341 switch (ch) { 342 case 'L': 343 phys = 0; 344 break; 345 case 'P': 346 phys = 1; 347 break; 348 default: 349 error("unknown option: -%c", optopt); 350 break; 351 } 352 } 353 argc -= optind; 354 argv += optind; 355 356 if (argc != 0) 357 error("too many arguments"); 358 359 if (!phys && getpwd()) { 360 out1str(curdir); 361 out1c('\n'); 362 } else { 363 if ((p = getpwd2()) == NULL) 364 error(".: %s", strerror(errno)); 365 out1str(p); 366 out1c('\n'); 367 } 368 369 return 0; 370 } 371 372 /* 373 * Get the current directory and cache the result in curdir. 374 */ 375 static char * 376 getpwd(void) 377 { 378 char *p; 379 380 if (curdir) 381 return curdir; 382 383 p = getpwd2(); 384 if (p != NULL) 385 curdir = savestr(p); 386 387 return curdir; 388 } 389 390 #define MAXPWD 256 391 392 /* 393 * Return the current directory. 394 */ 395 static char * 396 getpwd2(void) 397 { 398 char *pwd; 399 int i; 400 401 for (i = MAXPWD;; i *= 2) { 402 pwd = stalloc(i); 403 if (getcwd(pwd, i) != NULL) 404 return pwd; 405 stunalloc(pwd); 406 if (errno != ERANGE) 407 break; 408 } 409 410 return NULL; 411 } 412 413 /* 414 * Initialize PWD in a new shell. 415 * If the shell is interactive, we need to warn if this fails. 416 */ 417 void 418 pwd_init(int warn) 419 { 420 char *pwd; 421 struct stat stdot, stpwd; 422 423 pwd = lookupvar("PWD"); 424 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 425 stat(pwd, &stpwd) != -1 && 426 stdot.st_dev == stpwd.st_dev && 427 stdot.st_ino == stpwd.st_ino) { 428 if (curdir) 429 ckfree(curdir); 430 curdir = savestr(pwd); 431 } 432 if (getpwd() == NULL && warn) 433 out2fmt_flush("sh: cannot determine working directory\n"); 434 setvar("PWD", curdir, VEXPORT); 435 } 436