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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)cd.c 8.2 (Berkeley) 5/4/95 37 * $FreeBSD: head/bin/sh/cd.c 240541 2012-09-15 21:56:30Z jilles $ 38 */ 39 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 #include <errno.h> 46 #include <limits.h> 47 48 /* 49 * The cd and pwd commands. 50 */ 51 52 #include "shell.h" 53 #include "var.h" 54 #include "nodes.h" /* for jobs.h */ 55 #include "jobs.h" 56 #include "options.h" 57 #include "output.h" 58 #include "memalloc.h" 59 #include "error.h" 60 #include "exec.h" 61 #include "redir.h" 62 #include "mystring.h" 63 #include "show.h" 64 #include "cd.h" 65 #include "builtins.h" 66 67 static int cdlogical(char *); 68 static int cdphysical(char *); 69 static int docd(char *, int, int); 70 static char *getcomponent(void); 71 static char *findcwd(char *); 72 static void updatepwd(char *); 73 static char *getpwd(void); 74 static char *getpwd2(void); 75 76 static char *curdir = NULL; /* current working directory */ 77 static char *prevdir; /* previous 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 = prevdir ? prevdir : curdir; 115 if (dest) 116 print = 1; 117 else 118 dest = "."; 119 } 120 if (dest[0] == '/' || 121 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) || 122 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) || 123 (path = bltinlookup("CDPATH", 1)) == NULL) 124 path = nullstr; 125 while ((p = padvance(&path, dest)) != NULL) { 126 if (stat(p, &statb) < 0) { 127 if (errno != ENOENT) 128 errno1 = errno; 129 } else if (!S_ISDIR(statb.st_mode)) 130 errno1 = ENOTDIR; 131 else { 132 if (!print) { 133 /* 134 * XXX - rethink 135 */ 136 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 137 print = strcmp(p + 2, dest); 138 else 139 print = strcmp(p, dest); 140 } 141 rc = docd(p, print, phys); 142 if (rc >= 0) 143 return getcwderr ? rc : 0; 144 if (errno != ENOENT) 145 errno1 = errno; 146 } 147 } 148 error("%s: %s", dest, strerror(errno1)); 149 /*NOTREACHED*/ 150 return 0; 151 } 152 153 154 /* 155 * Actually change the directory. In an interactive shell, print the 156 * directory name if "print" is nonzero. 157 */ 158 static int 159 docd(char *dest, int print, int phys) 160 { 161 int rc; 162 163 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 164 165 /* If logical cd fails, fall back to physical. */ 166 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0) 167 return (-1); 168 169 if (print && iflag && curdir) 170 out1fmt("%s\n", curdir); 171 172 return (rc); 173 } 174 175 static int 176 cdlogical(char *dest) 177 { 178 char *p; 179 char *q; 180 char *component; 181 struct stat statb; 182 int first; 183 int badstat; 184 185 /* 186 * Check each component of the path. If we find a symlink or 187 * something we can't stat, clear curdir to force a getcwd() 188 * next time we get the value of the current directory. 189 */ 190 badstat = 0; 191 cdcomppath = stalloc(strlen(dest) + 1); 192 scopy(dest, cdcomppath); 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 = stalloc(strlen(dir) + 1); 286 scopy(dir, cdcomppath); 287 STARTSTACKSTR(new); 288 if (*dir != '/') { 289 STPUTS(curdir, new); 290 if (STTOPC(new) == '/') 291 STUNPUTC(new); 292 } 293 while ((p = getcomponent()) != NULL) { 294 if (equal(p, "..")) { 295 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 296 } else if (*p != '\0' && ! equal(p, ".")) { 297 STPUTC('/', new); 298 STPUTS(p, new); 299 } 300 } 301 if (new == stackblock()) 302 STPUTC('/', new); 303 STACKSTRNUL(new); 304 return stackblock(); 305 } 306 307 /* 308 * Update curdir (the name of the current directory) in response to a 309 * cd command. We also call hashcd to let the routines in exec.c know 310 * that the current directory has changed. 311 */ 312 static void 313 updatepwd(char *dir) 314 { 315 hashcd(); /* update command hash table */ 316 317 if (prevdir) 318 ckfree(prevdir); 319 prevdir = curdir; 320 curdir = dir ? savestr(dir) : NULL; 321 setvar("PWD", curdir, VEXPORT); 322 setvar("OLDPWD", prevdir, VEXPORT); 323 } 324 325 int 326 pwdcmd(int argc __unused, char **argv __unused) 327 { 328 char *p; 329 int ch, phys; 330 331 phys = Pflag; 332 while ((ch = nextopt("LP")) != '\0') { 333 switch (ch) { 334 case 'L': 335 phys = 0; 336 break; 337 case 'P': 338 phys = 1; 339 break; 340 } 341 } 342 343 if (*argptr != NULL) 344 error("too many arguments"); 345 346 if (!phys && getpwd()) { 347 out1str(curdir); 348 out1c('\n'); 349 } else { 350 if ((p = getpwd2()) == NULL) 351 error(".: %s", strerror(errno)); 352 out1str(p); 353 out1c('\n'); 354 } 355 356 return 0; 357 } 358 359 /* 360 * Get the current directory and cache the result in curdir. 361 */ 362 static char * 363 getpwd(void) 364 { 365 char *p; 366 367 if (curdir) 368 return curdir; 369 370 p = getpwd2(); 371 if (p != NULL) 372 curdir = savestr(p); 373 374 return curdir; 375 } 376 377 #define MAXPWD 256 378 379 /* 380 * Return the current directory. 381 */ 382 static char * 383 getpwd2(void) 384 { 385 char *pwd; 386 int i; 387 388 for (i = MAXPWD;; i *= 2) { 389 pwd = stalloc(i); 390 if (getcwd(pwd, i) != NULL) 391 return pwd; 392 stunalloc(pwd); 393 if (errno != ERANGE) 394 break; 395 } 396 397 return NULL; 398 } 399 400 /* 401 * Initialize PWD in a new shell. 402 * If the shell is interactive, we need to warn if this fails. 403 */ 404 void 405 pwd_init(int warn) 406 { 407 char *pwd; 408 struct stat stdot, stpwd; 409 410 pwd = lookupvar("PWD"); 411 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 412 stat(pwd, &stpwd) != -1 && 413 stdot.st_dev == stpwd.st_dev && 414 stdot.st_ino == stpwd.st_ino) { 415 if (curdir) 416 ckfree(curdir); 417 curdir = savestr(pwd); 418 } 419 if (getpwd() == NULL && warn) 420 out2fmt_flush("sh: cannot determine working directory\n"); 421 setvar("PWD", curdir, VEXPORT); 422 } 423