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. 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 = ""; 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; 185 186 /* 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 = stsavestr(dest); 193 STARTSTACKSTR(p); 194 if (*dest == '/') { 195 STPUTC('/', p); 196 cdcomppath++; 197 } 198 first = 1; 199 while ((q = getcomponent()) != NULL) { 200 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 201 continue; 202 if (! first) 203 STPUTC('/', p); 204 first = 0; 205 component = q; 206 STPUTS(q, p); 207 if (equal(component, "..")) 208 continue; 209 STACKSTRNUL(p); 210 if (lstat(stackblock(), &statb) < 0) { 211 badstat = 1; 212 break; 213 } 214 } 215 216 INTOFF; 217 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 218 INTON; 219 return (-1); 220 } 221 updatepwd(p); 222 INTON; 223 return (0); 224 } 225 226 static int 227 cdphysical(char *dest) 228 { 229 char *p; 230 int rc = 0; 231 232 INTOFF; 233 if (chdir(dest) < 0) { 234 INTON; 235 return (-1); 236 } 237 p = findcwd(NULL); 238 if (p == NULL) { 239 warning("warning: failed to get name of current directory"); 240 rc = 1; 241 } 242 updatepwd(p); 243 INTON; 244 return (rc); 245 } 246 247 /* 248 * Get the next component of the path name pointed to by cdcomppath. 249 * This routine overwrites the string pointed to by cdcomppath. 250 */ 251 static char * 252 getcomponent(void) 253 { 254 char *p; 255 char *start; 256 257 if ((p = cdcomppath) == NULL) 258 return NULL; 259 start = cdcomppath; 260 while (*p != '/' && *p != '\0') 261 p++; 262 if (*p == '\0') { 263 cdcomppath = NULL; 264 } else { 265 *p++ = '\0'; 266 cdcomppath = p; 267 } 268 return start; 269 } 270 271 272 static char * 273 findcwd(char *dir) 274 { 275 char *new; 276 char *p; 277 278 /* 279 * If our argument is NULL, we don't know the current directory 280 * any more because we traversed a symbolic link or something 281 * we couldn't stat(). 282 */ 283 if (dir == NULL || curdir == NULL) 284 return getpwd2(); 285 cdcomppath = stsavestr(dir); 286 STARTSTACKSTR(new); 287 if (*dir != '/') { 288 STPUTS(curdir, new); 289 if (STTOPC(new) == '/') 290 STUNPUTC(new); 291 } 292 while ((p = getcomponent()) != NULL) { 293 if (equal(p, "..")) { 294 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 295 } else if (*p != '\0' && ! equal(p, ".")) { 296 STPUTC('/', new); 297 STPUTS(p, new); 298 } 299 } 300 if (new == stackblock()) 301 STPUTC('/', new); 302 STACKSTRNUL(new); 303 return stackblock(); 304 } 305 306 /* 307 * Update curdir (the name of the current directory) in response to a 308 * cd command. We also call hashcd to let the routines in exec.c know 309 * that the current directory has changed. 310 */ 311 static void 312 updatepwd(char *dir) 313 { 314 hashcd(); /* update command hash table */ 315 316 if (prevdir) 317 ckfree(prevdir); 318 prevdir = curdir; 319 curdir = dir ? savestr(dir) : NULL; 320 setvar("PWD", curdir, VEXPORT); 321 setvar("OLDPWD", prevdir, VEXPORT); 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