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 __unused, char **argv __unused) 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 phys = Pflag; 93 while ((ch = nextopt("eLP")) != '\0') { 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 } 105 } 106 107 if (*argptr != NULL && argptr[1] != NULL) 108 error("too many arguments"); 109 110 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 111 error("HOME not set"); 112 if (*dest == '\0') 113 dest = "."; 114 if (dest[0] == '-' && dest[1] == '\0') { 115 dest = prevdir ? prevdir : curdir; 116 if (dest) 117 print = 1; 118 else 119 dest = "."; 120 } 121 if (dest[0] == '/' || 122 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) || 123 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) || 124 (path = bltinlookup("CDPATH", 1)) == NULL) 125 path = nullstr; 126 while ((p = padvance(&path, dest)) != NULL) { 127 if (stat(p, &statb) < 0) { 128 if (errno != ENOENT) 129 errno1 = errno; 130 } else if (!S_ISDIR(statb.st_mode)) 131 errno1 = ENOTDIR; 132 else { 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 size_t len; 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 len = strlen(dest); 194 cdcomppath = stalloc(len + 1); 195 memcpy(cdcomppath, dest, len + 1); 196 STARTSTACKSTR(p); 197 if (*dest == '/') { 198 STPUTC('/', p); 199 cdcomppath++; 200 } 201 first = 1; 202 while ((q = getcomponent()) != NULL) { 203 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 204 continue; 205 if (! first) 206 STPUTC('/', p); 207 first = 0; 208 component = q; 209 STPUTS(q, p); 210 if (equal(component, "..")) 211 continue; 212 STACKSTRNUL(p); 213 if (lstat(stackblock(), &statb) < 0) { 214 badstat = 1; 215 break; 216 } 217 } 218 219 INTOFF; 220 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 221 INTON; 222 return (-1); 223 } 224 updatepwd(p); 225 INTON; 226 return (0); 227 } 228 229 static int 230 cdphysical(char *dest) 231 { 232 char *p; 233 int rc = 0; 234 235 INTOFF; 236 if (chdir(dest) < 0) { 237 INTON; 238 return (-1); 239 } 240 p = findcwd(NULL); 241 if (p == NULL) { 242 warning("warning: failed to get name of current directory"); 243 rc = 1; 244 } 245 updatepwd(p); 246 INTON; 247 return (rc); 248 } 249 250 /* 251 * Get the next component of the path name pointed to by cdcomppath. 252 * This routine overwrites the string pointed to by cdcomppath. 253 */ 254 static char * 255 getcomponent(void) 256 { 257 char *p; 258 char *start; 259 260 if ((p = cdcomppath) == NULL) 261 return NULL; 262 start = cdcomppath; 263 while (*p != '/' && *p != '\0') 264 p++; 265 if (*p == '\0') { 266 cdcomppath = NULL; 267 } else { 268 *p++ = '\0'; 269 cdcomppath = p; 270 } 271 return start; 272 } 273 274 275 static char * 276 findcwd(char *dir) 277 { 278 char *new; 279 char *p; 280 size_t len; 281 282 /* 283 * If our argument is NULL, we don't know the current directory 284 * any more because we traversed a symbolic link or something 285 * we couldn't stat(). 286 */ 287 if (dir == NULL || curdir == NULL) 288 return getpwd2(); 289 len = strlen(dir); 290 cdcomppath = stalloc(len + 1); 291 memcpy(cdcomppath, dir, len + 1); 292 STARTSTACKSTR(new); 293 if (*dir != '/') { 294 STPUTS(curdir, new); 295 if (STTOPC(new) == '/') 296 STUNPUTC(new); 297 } 298 while ((p = getcomponent()) != NULL) { 299 if (equal(p, "..")) { 300 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 301 } else if (*p != '\0' && ! equal(p, ".")) { 302 STPUTC('/', new); 303 STPUTS(p, new); 304 } 305 } 306 if (new == stackblock()) 307 STPUTC('/', new); 308 STACKSTRNUL(new); 309 return stackblock(); 310 } 311 312 /* 313 * Update curdir (the name of the current directory) in response to a 314 * cd command. We also call hashcd to let the routines in exec.c know 315 * that the current directory has changed. 316 */ 317 static void 318 updatepwd(char *dir) 319 { 320 hashcd(); /* update command hash table */ 321 322 if (prevdir) 323 ckfree(prevdir); 324 prevdir = curdir; 325 curdir = dir ? savestr(dir) : NULL; 326 setvar("PWD", curdir, VEXPORT); 327 setvar("OLDPWD", prevdir, VEXPORT); 328 } 329 330 int 331 pwdcmd(int argc __unused, char **argv __unused) 332 { 333 char *p; 334 int ch, phys; 335 336 phys = Pflag; 337 while ((ch = nextopt("LP")) != '\0') { 338 switch (ch) { 339 case 'L': 340 phys = 0; 341 break; 342 case 'P': 343 phys = 1; 344 break; 345 } 346 } 347 348 if (*argptr != NULL) 349 error("too many arguments"); 350 351 if (!phys && getpwd()) { 352 out1str(curdir); 353 out1c('\n'); 354 } else { 355 if ((p = getpwd2()) == NULL) 356 error(".: %s", strerror(errno)); 357 out1str(p); 358 out1c('\n'); 359 } 360 361 return 0; 362 } 363 364 /* 365 * Get the current directory and cache the result in curdir. 366 */ 367 static char * 368 getpwd(void) 369 { 370 char *p; 371 372 if (curdir) 373 return curdir; 374 375 p = getpwd2(); 376 if (p != NULL) 377 curdir = savestr(p); 378 379 return curdir; 380 } 381 382 #define MAXPWD 256 383 384 /* 385 * Return the current directory. 386 */ 387 static char * 388 getpwd2(void) 389 { 390 char *pwd; 391 int i; 392 393 for (i = MAXPWD;; i *= 2) { 394 pwd = stalloc(i); 395 if (getcwd(pwd, i) != NULL) 396 return pwd; 397 stunalloc(pwd); 398 if (errno != ERANGE) 399 break; 400 } 401 402 return NULL; 403 } 404 405 /* 406 * Initialize PWD in a new shell. 407 * If the shell is interactive, we need to warn if this fails. 408 */ 409 void 410 pwd_init(int warn) 411 { 412 char *pwd; 413 struct stat stdot, stpwd; 414 415 pwd = lookupvar("PWD"); 416 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 417 stat(pwd, &stpwd) != -1 && 418 stdot.st_dev == stpwd.st_dev && 419 stdot.st_ino == stpwd.st_ino) { 420 if (curdir) 421 ckfree(curdir); 422 curdir = savestr(pwd); 423 } 424 if (getpwd() == NULL && warn) 425 out2fmt_flush("sh: cannot determine working directory\n"); 426 setvar("PWD", curdir, VEXPORT); 427 } 428