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 && S_ISDIR(statb.st_mode)) { 134 if (!print) { 135 /* 136 * XXX - rethink 137 */ 138 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 139 print = strcmp(p + 2, dest); 140 else 141 print = strcmp(p, dest); 142 } 143 rc = docd(p, print, phys); 144 if (rc >= 0) 145 return getcwderr ? rc : 0; 146 if (errno != ENOENT) 147 errno1 = errno; 148 } 149 } 150 error("%s: %s", dest, strerror(errno1)); 151 /*NOTREACHED*/ 152 return 0; 153 } 154 155 156 /* 157 * Actually change the directory. In an interactive shell, print the 158 * directory name if "print" is nonzero. 159 */ 160 static int 161 docd(char *dest, int print, int phys) 162 { 163 int rc; 164 165 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 166 167 /* If logical cd fails, fall back to physical. */ 168 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0) 169 return (-1); 170 171 if (print && iflag && curdir) 172 out1fmt("%s\n", curdir); 173 174 return (rc); 175 } 176 177 static int 178 cdlogical(char *dest) 179 { 180 char *p; 181 char *q; 182 char *component; 183 struct stat statb; 184 int first; 185 int badstat; 186 187 /* 188 * Check each component of the path. If we find a symlink or 189 * something we can't stat, clear curdir to force a getcwd() 190 * next time we get the value of the current directory. 191 */ 192 badstat = 0; 193 cdcomppath = stalloc(strlen(dest) + 1); 194 scopy(dest, cdcomppath); 195 STARTSTACKSTR(p); 196 if (*dest == '/') { 197 STPUTC('/', p); 198 cdcomppath++; 199 } 200 first = 1; 201 while ((q = getcomponent()) != NULL) { 202 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 203 continue; 204 if (! first) 205 STPUTC('/', p); 206 first = 0; 207 component = q; 208 STPUTS(q, p); 209 if (equal(component, "..")) 210 continue; 211 STACKSTRNUL(p); 212 if (lstat(stackblock(), &statb) < 0) { 213 badstat = 1; 214 break; 215 } 216 } 217 218 INTOFF; 219 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 220 INTON; 221 return (-1); 222 } 223 updatepwd(p); 224 INTON; 225 return (0); 226 } 227 228 static int 229 cdphysical(char *dest) 230 { 231 char *p; 232 int rc = 0; 233 234 INTOFF; 235 if (chdir(dest) < 0) { 236 INTON; 237 return (-1); 238 } 239 p = findcwd(NULL); 240 if (p == NULL) { 241 warning("warning: failed to get name of current directory"); 242 rc = 1; 243 } 244 updatepwd(p); 245 INTON; 246 return (rc); 247 } 248 249 /* 250 * Get the next component of the path name pointed to by cdcomppath. 251 * This routine overwrites the string pointed to by cdcomppath. 252 */ 253 static char * 254 getcomponent(void) 255 { 256 char *p; 257 char *start; 258 259 if ((p = cdcomppath) == NULL) 260 return NULL; 261 start = cdcomppath; 262 while (*p != '/' && *p != '\0') 263 p++; 264 if (*p == '\0') { 265 cdcomppath = NULL; 266 } else { 267 *p++ = '\0'; 268 cdcomppath = p; 269 } 270 return start; 271 } 272 273 274 static char * 275 findcwd(char *dir) 276 { 277 char *new; 278 char *p; 279 280 /* 281 * If our argument is NULL, we don't know the current directory 282 * any more because we traversed a symbolic link or something 283 * we couldn't stat(). 284 */ 285 if (dir == NULL || curdir == NULL) 286 return getpwd2(); 287 cdcomppath = stalloc(strlen(dir) + 1); 288 scopy(dir, cdcomppath); 289 STARTSTACKSTR(new); 290 if (*dir != '/') { 291 STPUTS(curdir, new); 292 if (STTOPC(new) == '/') 293 STUNPUTC(new); 294 } 295 while ((p = getcomponent()) != NULL) { 296 if (equal(p, "..")) { 297 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 298 } else if (*p != '\0' && ! equal(p, ".")) { 299 STPUTC('/', new); 300 STPUTS(p, new); 301 } 302 } 303 if (new == stackblock()) 304 STPUTC('/', new); 305 STACKSTRNUL(new); 306 return stackblock(); 307 } 308 309 /* 310 * Update curdir (the name of the current directory) in response to a 311 * cd command. We also call hashcd to let the routines in exec.c know 312 * that the current directory has changed. 313 */ 314 static void 315 updatepwd(char *dir) 316 { 317 hashcd(); /* update command hash table */ 318 319 if (prevdir) 320 ckfree(prevdir); 321 prevdir = curdir; 322 curdir = dir ? savestr(dir) : NULL; 323 setvar("PWD", curdir, VEXPORT); 324 setvar("OLDPWD", prevdir, VEXPORT); 325 } 326 327 int 328 pwdcmd(int argc, char **argv) 329 { 330 char *p; 331 int ch, phys; 332 333 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 334 phys = Pflag; 335 while ((ch = getopt(argc, argv, "LP")) != -1) { 336 switch (ch) { 337 case 'L': 338 phys = 0; 339 break; 340 case 'P': 341 phys = 1; 342 break; 343 default: 344 error("unknown option: -%c", optopt); 345 break; 346 } 347 } 348 argc -= optind; 349 argv += optind; 350 351 if (argc != 0) 352 error("too many arguments"); 353 354 if (!phys && getpwd()) { 355 out1str(curdir); 356 out1c('\n'); 357 } else { 358 if ((p = getpwd2()) == NULL) 359 error(".: %s", strerror(errno)); 360 out1str(p); 361 out1c('\n'); 362 } 363 364 return 0; 365 } 366 367 /* 368 * Get the current directory and cache the result in curdir. 369 */ 370 static char * 371 getpwd(void) 372 { 373 char *p; 374 375 if (curdir) 376 return curdir; 377 378 p = getpwd2(); 379 if (p != NULL) 380 curdir = savestr(p); 381 382 return curdir; 383 } 384 385 #define MAXPWD 256 386 387 /* 388 * Return the current directory. 389 */ 390 static char * 391 getpwd2(void) 392 { 393 char *pwd; 394 int i; 395 396 for (i = MAXPWD;; i *= 2) { 397 pwd = stalloc(i); 398 if (getcwd(pwd, i) != NULL) 399 return pwd; 400 stunalloc(pwd); 401 if (errno != ERANGE) 402 break; 403 } 404 405 return NULL; 406 } 407 408 /* 409 * Initialize PWD in a new shell. 410 * If the shell is interactive, we need to warn if this fails. 411 */ 412 void 413 pwd_init(int warn) 414 { 415 char *pwd; 416 struct stat stdot, stpwd; 417 418 pwd = lookupvar("PWD"); 419 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 420 stat(pwd, &stpwd) != -1 && 421 stdot.st_dev == stpwd.st_dev && 422 stdot.st_ino == stpwd.st_ino) { 423 if (curdir) 424 ckfree(curdir); 425 curdir = savestr(pwd); 426 } 427 if (getpwd() == NULL && warn) 428 out2fmt_flush("sh: cannot determine working directory\n"); 429 setvar("PWD", curdir, VEXPORT); 430 } 431