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 * @(#)cd.c 8.2 (Berkeley) 5/4/95 33 * $FreeBSD: head/bin/sh/cd.c 240541 2012-09-15 21:56:30Z jilles $ 34 */ 35 36 #include <sys/types.h> 37 #include <sys/stat.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <unistd.h> 41 #include <errno.h> 42 #include <limits.h> 43 44 /* 45 * The cd and pwd commands. 46 */ 47 48 #include "shell.h" 49 #include "var.h" 50 #include "nodes.h" /* for jobs.h */ 51 #include "jobs.h" 52 #include "options.h" 53 #include "output.h" 54 #include "memalloc.h" 55 #include "error.h" 56 #include "exec.h" 57 #include "redir.h" 58 #include "mystring.h" 59 #include "show.h" 60 #include "cd.h" 61 #include "builtins.h" 62 63 static int cdlogical(char *); 64 static int cdphysical(char *); 65 static int docd(char *, int, int); 66 static char *getcomponent(void); 67 static char *findcwd(char *); 68 static void updatepwd(char *); 69 static char *getpwd(void); 70 static char *getpwd2(void); 71 72 static char *curdir = NULL; /* current working directory */ 73 static char *prevdir; /* previous working directory */ 74 static char *cdcomppath; 75 76 int 77 cdcmd(int argc __unused, char **argv __unused) 78 { 79 const char *dest; 80 const char *path; 81 char *p; 82 struct stat statb; 83 int ch, phys, print = 0, getcwderr = 0; 84 int rc; 85 int errno1 = ENOENT; 86 87 phys = Pflag; 88 while ((ch = nextopt("eLP")) != '\0') { 89 switch (ch) { 90 case 'e': 91 getcwderr = 1; 92 break; 93 case 'L': 94 phys = 0; 95 break; 96 case 'P': 97 phys = 1; 98 break; 99 } 100 } 101 102 if (*argptr != NULL && argptr[1] != NULL) 103 error("too many arguments"); 104 105 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 106 error("HOME not set"); 107 if (*dest == '\0') 108 dest = "."; 109 if (dest[0] == '-' && dest[1] == '\0') { 110 dest = prevdir ? prevdir : curdir; 111 if (dest) 112 print = 1; 113 else 114 dest = "."; 115 } 116 if (dest[0] == '/' || 117 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) || 118 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) || 119 (path = bltinlookup("CDPATH", 1)) == NULL) 120 path = nullstr; 121 while ((p = padvance(&path, dest)) != NULL) { 122 if (stat(p, &statb) < 0) { 123 if (errno != ENOENT) 124 errno1 = errno; 125 } else if (!S_ISDIR(statb.st_mode)) 126 errno1 = ENOTDIR; 127 else { 128 if (!print) { 129 /* 130 * XXX - rethink 131 */ 132 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 133 print = strcmp(p + 2, dest); 134 else 135 print = strcmp(p, dest); 136 } 137 rc = docd(p, print, phys); 138 if (rc >= 0) 139 return getcwderr ? rc : 0; 140 if (errno != ENOENT) 141 errno1 = errno; 142 } 143 } 144 error("%s: %s", dest, strerror(errno1)); 145 /*NOTREACHED*/ 146 return 0; 147 } 148 149 150 /* 151 * Actually change the directory. In an interactive shell, print the 152 * directory name if "print" is nonzero. 153 */ 154 static int 155 docd(char *dest, int print, int phys) 156 { 157 int rc; 158 159 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 160 161 /* If logical cd fails, fall back to physical. */ 162 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0) 163 return (-1); 164 165 if (print && iflag && curdir) 166 out1fmt("%s\n", curdir); 167 168 return (rc); 169 } 170 171 static int 172 cdlogical(char *dest) 173 { 174 char *p; 175 char *q; 176 char *component; 177 struct stat statb; 178 int first; 179 int badstat; 180 181 /* 182 * Check each component of the path. If we find a symlink or 183 * something we can't stat, clear curdir to force a getcwd() 184 * next time we get the value of the current directory. 185 */ 186 badstat = 0; 187 cdcomppath = stalloc(strlen(dest) + 1); 188 scopy(dest, cdcomppath); 189 STARTSTACKSTR(p); 190 if (*dest == '/') { 191 STPUTC('/', p); 192 cdcomppath++; 193 } 194 first = 1; 195 while ((q = getcomponent()) != NULL) { 196 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 197 continue; 198 if (! first) 199 STPUTC('/', p); 200 first = 0; 201 component = q; 202 STPUTS(q, p); 203 if (equal(component, "..")) 204 continue; 205 STACKSTRNUL(p); 206 if (lstat(stackblock(), &statb) < 0) { 207 badstat = 1; 208 break; 209 } 210 } 211 212 INTOFF; 213 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 214 INTON; 215 return (-1); 216 } 217 updatepwd(p); 218 INTON; 219 return (0); 220 } 221 222 static int 223 cdphysical(char *dest) 224 { 225 char *p; 226 int rc = 0; 227 228 INTOFF; 229 if (chdir(dest) < 0) { 230 INTON; 231 return (-1); 232 } 233 p = findcwd(NULL); 234 if (p == NULL) { 235 warning("warning: failed to get name of current directory"); 236 rc = 1; 237 } 238 updatepwd(p); 239 INTON; 240 return (rc); 241 } 242 243 /* 244 * Get the next component of the path name pointed to by cdcomppath. 245 * This routine overwrites the string pointed to by cdcomppath. 246 */ 247 static char * 248 getcomponent(void) 249 { 250 char *p; 251 char *start; 252 253 if ((p = cdcomppath) == NULL) 254 return NULL; 255 start = cdcomppath; 256 while (*p != '/' && *p != '\0') 257 p++; 258 if (*p == '\0') { 259 cdcomppath = NULL; 260 } else { 261 *p++ = '\0'; 262 cdcomppath = p; 263 } 264 return start; 265 } 266 267 268 static char * 269 findcwd(char *dir) 270 { 271 char *new; 272 char *p; 273 274 /* 275 * If our argument is NULL, we don't know the current directory 276 * any more because we traversed a symbolic link or something 277 * we couldn't stat(). 278 */ 279 if (dir == NULL || curdir == NULL) 280 return getpwd2(); 281 cdcomppath = stalloc(strlen(dir) + 1); 282 scopy(dir, cdcomppath); 283 STARTSTACKSTR(new); 284 if (*dir != '/') { 285 STPUTS(curdir, new); 286 if (STTOPC(new) == '/') 287 STUNPUTC(new); 288 } 289 while ((p = getcomponent()) != NULL) { 290 if (equal(p, "..")) { 291 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 292 } else if (*p != '\0' && ! equal(p, ".")) { 293 STPUTC('/', new); 294 STPUTS(p, new); 295 } 296 } 297 if (new == stackblock()) 298 STPUTC('/', new); 299 STACKSTRNUL(new); 300 return stackblock(); 301 } 302 303 /* 304 * Update curdir (the name of the current directory) in response to a 305 * cd command. We also call hashcd to let the routines in exec.c know 306 * that the current directory has changed. 307 */ 308 static void 309 updatepwd(char *dir) 310 { 311 hashcd(); /* update command hash table */ 312 313 if (prevdir) 314 ckfree(prevdir); 315 prevdir = curdir; 316 curdir = dir ? savestr(dir) : NULL; 317 setvar("PWD", curdir, VEXPORT); 318 setvar("OLDPWD", prevdir, VEXPORT); 319 } 320 321 int 322 pwdcmd(int argc __unused, char **argv __unused) 323 { 324 char *p; 325 int ch, phys; 326 327 phys = Pflag; 328 while ((ch = nextopt("LP")) != '\0') { 329 switch (ch) { 330 case 'L': 331 phys = 0; 332 break; 333 case 'P': 334 phys = 1; 335 break; 336 } 337 } 338 339 if (*argptr != NULL) 340 error("too many arguments"); 341 342 if (!phys && getpwd()) { 343 out1str(curdir); 344 out1c('\n'); 345 } else { 346 if ((p = getpwd2()) == NULL) 347 error(".: %s", strerror(errno)); 348 out1str(p); 349 out1c('\n'); 350 } 351 352 return 0; 353 } 354 355 /* 356 * Get the current directory and cache the result in curdir. 357 */ 358 static char * 359 getpwd(void) 360 { 361 char *p; 362 363 if (curdir) 364 return curdir; 365 366 p = getpwd2(); 367 if (p != NULL) 368 curdir = savestr(p); 369 370 return curdir; 371 } 372 373 #define MAXPWD 256 374 375 /* 376 * Return the current directory. 377 */ 378 static char * 379 getpwd2(void) 380 { 381 char *pwd; 382 int i; 383 384 for (i = MAXPWD;; i *= 2) { 385 pwd = stalloc(i); 386 if (getcwd(pwd, i) != NULL) 387 return pwd; 388 stunalloc(pwd); 389 if (errno != ERANGE) 390 break; 391 } 392 393 return NULL; 394 } 395 396 /* 397 * Initialize PWD in a new shell. 398 * If the shell is interactive, we need to warn if this fails. 399 */ 400 void 401 pwd_init(int warn) 402 { 403 char *pwd; 404 struct stat stdot, stpwd; 405 406 pwd = lookupvar("PWD"); 407 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 408 stat(pwd, &stpwd) != -1 && 409 stdot.st_dev == stpwd.st_dev && 410 stdot.st_ino == stpwd.st_ino) { 411 if (curdir) 412 ckfree(curdir); 413 curdir = savestr(pwd); 414 } 415 if (getpwd() == NULL && warn) 416 out2fmt_flush("sh: cannot determine working directory\n"); 417 setvar("PWD", curdir, VEXPORT); 418 } 419