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