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