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 * @(#)cd.c 8.2 (Berkeley) 5/4/95 37 * $FreeBSD: src/bin/sh/cd.c,v 1.49 2011/06/13 21:03:27 jilles Exp $ 38 */ 39 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 #include <errno.h> 46 #include <limits.h> 47 48 /* 49 * The cd and pwd commands. 50 */ 51 52 #include "shell.h" 53 #include "var.h" 54 #include "nodes.h" /* for jobs.h */ 55 #include "jobs.h" 56 #include "options.h" 57 #include "output.h" 58 #include "memalloc.h" 59 #include "error.h" 60 #include "exec.h" 61 #include "redir.h" 62 #include "mystring.h" 63 #include "show.h" 64 #include "cd.h" 65 #include "builtins.h" 66 67 static int cdlogical(char *); 68 static int cdphysical(char *); 69 static int docd(char *, int, int); 70 static char *getcomponent(void); 71 static char *findcwd(char *); 72 static void updatepwd(char *); 73 static char *getpwd(void); 74 static char *getpwd2(void); 75 76 static char *curdir = NULL; /* current working directory */ 77 static char *prevdir; /* previous working directory */ 78 static char *cdcomppath; 79 80 int 81 cdcmd(int argc, char **argv) 82 { 83 const char *dest; 84 const char *path; 85 char *p; 86 struct stat statb; 87 int ch, phys, print = 0, getcwderr = 0; 88 int rc; 89 int errno1 = ENOENT; 90 91 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 92 phys = Pflag; 93 while ((ch = getopt(argc, argv, "eLP")) != -1) { 94 switch (ch) { 95 case 'e': 96 getcwderr = 1; 97 break; 98 case 'L': 99 phys = 0; 100 break; 101 case 'P': 102 phys = 1; 103 break; 104 default: 105 error("unknown option: -%c", optopt); 106 break; 107 } 108 } 109 argc -= optind; 110 argv += optind; 111 112 if (argc > 1) 113 error("too many arguments"); 114 115 if ((dest = *argv) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 116 error("HOME not set"); 117 if (*dest == '\0') 118 dest = "."; 119 if (dest[0] == '-' && dest[1] == '\0') { 120 dest = prevdir ? prevdir : curdir; 121 if (dest) 122 print = 1; 123 else 124 dest = "."; 125 } 126 if (dest[0] == '/' || 127 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) || 128 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) || 129 (path = bltinlookup("CDPATH", 1)) == NULL) 130 path = nullstr; 131 while ((p = padvance(&path, dest)) != NULL) { 132 if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { 133 if (!print) { 134 /* 135 * XXX - rethink 136 */ 137 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 138 print = strcmp(p + 2, dest); 139 else 140 print = strcmp(p, dest); 141 } 142 rc = docd(p, print, phys); 143 if (rc >= 0) 144 return getcwderr ? rc : 0; 145 if (errno != ENOENT) 146 errno1 = errno; 147 } 148 } 149 error("%s: %s", dest, strerror(errno1)); 150 /*NOTREACHED*/ 151 return 0; 152 } 153 154 155 /* 156 * Actually change the directory. In an interactive shell, print the 157 * directory name if "print" is nonzero. 158 */ 159 static int 160 docd(char *dest, int print, int phys) 161 { 162 int rc; 163 164 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 165 166 /* If logical cd fails, fall back to physical. */ 167 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0) 168 return (-1); 169 170 if (print && iflag && curdir) 171 out1fmt("%s\n", curdir); 172 173 return (rc); 174 } 175 176 static int 177 cdlogical(char *dest) 178 { 179 char *p; 180 char *q; 181 char *component; 182 struct stat statb; 183 int first; 184 int badstat; 185 186 /* 187 * Check each component of the path. If we find a symlink or 188 * something we can't stat, clear curdir to force a getcwd() 189 * next time we get the value of the current directory. 190 */ 191 badstat = 0; 192 cdcomppath = stalloc(strlen(dest) + 1); 193 scopy(dest, cdcomppath); 194 STARTSTACKSTR(p); 195 if (*dest == '/') { 196 STPUTC('/', p); 197 cdcomppath++; 198 } 199 first = 1; 200 while ((q = getcomponent()) != NULL) { 201 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 202 continue; 203 if (! first) 204 STPUTC('/', p); 205 first = 0; 206 component = q; 207 STPUTS(q, p); 208 if (equal(component, "..")) 209 continue; 210 STACKSTRNUL(p); 211 if (lstat(stackblock(), &statb) < 0) { 212 badstat = 1; 213 break; 214 } 215 } 216 217 INTOFF; 218 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 219 INTON; 220 return (-1); 221 } 222 updatepwd(p); 223 INTON; 224 return (0); 225 } 226 227 static int 228 cdphysical(char *dest) 229 { 230 char *p; 231 int rc = 0; 232 233 INTOFF; 234 if (chdir(dest) < 0) { 235 INTON; 236 return (-1); 237 } 238 p = findcwd(NULL); 239 if (p == NULL) { 240 warning("warning: failed to get name of current directory"); 241 rc = 1; 242 } 243 updatepwd(p); 244 INTON; 245 return (rc); 246 } 247 248 /* 249 * Get the next component of the path name pointed to by cdcomppath. 250 * This routine overwrites the string pointed to by cdcomppath. 251 */ 252 static char * 253 getcomponent(void) 254 { 255 char *p; 256 char *start; 257 258 if ((p = cdcomppath) == NULL) 259 return NULL; 260 start = cdcomppath; 261 while (*p != '/' && *p != '\0') 262 p++; 263 if (*p == '\0') { 264 cdcomppath = NULL; 265 } else { 266 *p++ = '\0'; 267 cdcomppath = p; 268 } 269 return start; 270 } 271 272 273 static char * 274 findcwd(char *dir) 275 { 276 char *new; 277 char *p; 278 279 /* 280 * If our argument is NULL, we don't know the current directory 281 * any more because we traversed a symbolic link or something 282 * we couldn't stat(). 283 */ 284 if (dir == NULL || curdir == NULL) 285 return getpwd2(); 286 cdcomppath = stalloc(strlen(dir) + 1); 287 scopy(dir, cdcomppath); 288 STARTSTACKSTR(new); 289 if (*dir != '/') { 290 STPUTS(curdir, new); 291 if (STTOPC(new) == '/') 292 STUNPUTC(new); 293 } 294 while ((p = getcomponent()) != NULL) { 295 if (equal(p, "..")) { 296 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 297 } else if (*p != '\0' && ! equal(p, ".")) { 298 STPUTC('/', new); 299 STPUTS(p, new); 300 } 301 } 302 if (new == stackblock()) 303 STPUTC('/', new); 304 STACKSTRNUL(new); 305 return stackblock(); 306 } 307 308 /* 309 * Update curdir (the name of the current directory) in response to a 310 * cd command. We also call hashcd to let the routines in exec.c know 311 * that the current directory has changed. 312 */ 313 static void 314 updatepwd(char *dir) 315 { 316 hashcd(); /* update command hash table */ 317 318 if (prevdir) 319 ckfree(prevdir); 320 prevdir = curdir; 321 curdir = dir ? savestr(dir) : NULL; 322 setvar("PWD", curdir, VEXPORT); 323 setvar("OLDPWD", prevdir, VEXPORT); 324 } 325 326 int 327 pwdcmd(int argc, char **argv) 328 { 329 char *p; 330 int ch, phys; 331 332 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 333 phys = Pflag; 334 while ((ch = getopt(argc, argv, "LP")) != -1) { 335 switch (ch) { 336 case 'L': 337 phys = 0; 338 break; 339 case 'P': 340 phys = 1; 341 break; 342 default: 343 error("unknown option: -%c", optopt); 344 break; 345 } 346 } 347 argc -= optind; 348 argv += optind; 349 350 if (argc != 0) 351 error("too many arguments"); 352 353 if (!phys && getpwd()) { 354 out1str(curdir); 355 out1c('\n'); 356 } else { 357 if ((p = getpwd2()) == NULL) 358 error(".: %s", strerror(errno)); 359 out1str(p); 360 out1c('\n'); 361 } 362 363 return 0; 364 } 365 366 /* 367 * Get the current directory and cache the result in curdir. 368 */ 369 static char * 370 getpwd(void) 371 { 372 char *p; 373 374 if (curdir) 375 return curdir; 376 377 p = getpwd2(); 378 if (p != NULL) 379 curdir = savestr(p); 380 381 return curdir; 382 } 383 384 #define MAXPWD 256 385 386 /* 387 * Return the current directory. 388 */ 389 static char * 390 getpwd2(void) 391 { 392 char *pwd; 393 int i; 394 395 for (i = MAXPWD;; i *= 2) { 396 pwd = stalloc(i); 397 if (getcwd(pwd, i) != NULL) 398 return pwd; 399 stunalloc(pwd); 400 if (errno != ERANGE) 401 break; 402 } 403 404 return NULL; 405 } 406 407 /* 408 * Initialize PWD in a new shell. 409 * If the shell is interactive, we need to warn if this fails. 410 */ 411 void 412 pwd_init(int warn) 413 { 414 char *pwd; 415 struct stat stdot, stpwd; 416 417 pwd = lookupvar("PWD"); 418 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 419 stat(pwd, &stpwd) != -1 && 420 stdot.st_dev == stpwd.st_dev && 421 stdot.st_ino == stpwd.st_ino) { 422 if (curdir) 423 ckfree(curdir); 424 curdir = savestr(pwd); 425 } 426 if (getpwd() == NULL && warn) 427 out2fmt_flush("sh: cannot determine working directory\n"); 428 setvar("PWD", curdir, VEXPORT); 429 } 430