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 *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 = nullstr; 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 = stalloc(strlen(dest) + 1); 193 scopy(dest, cdcomppath); 194 STARTSTACKSTR(p); 195 if (*dest == '/') { 196 STPUTC('/', p); 197 cdcomppath++; 198 } 199 first = 1; 200 while ((q = getcomponent()) != NULL) { 201 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 202 continue; 203 if (! first) 204 STPUTC('/', p); 205 first = 0; 206 component = q; 207 STPUTS(q, p); 208 if (equal(component, "..")) 209 continue; 210 STACKSTRNUL(p); 211 if (lstat(stackblock(), &statb) < 0) { 212 badstat = 1; 213 break; 214 } 215 } 216 217 INTOFF; 218 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 219 INTON; 220 return (-1); 221 } 222 updatepwd(p); 223 INTON; 224 return (0); 225 } 226 227 static int 228 cdphysical(char *dest) 229 { 230 char *p; 231 int rc = 0; 232 233 INTOFF; 234 if (chdir(dest) < 0) { 235 INTON; 236 return (-1); 237 } 238 p = findcwd(NULL); 239 if (p == NULL) { 240 warning("warning: failed to get name of current directory"); 241 rc = 1; 242 } 243 updatepwd(p); 244 INTON; 245 return (rc); 246 } 247 248 /* 249 * Get the next component of the path name pointed to by cdcomppath. 250 * This routine overwrites the string pointed to by cdcomppath. 251 */ 252 static char * 253 getcomponent(void) 254 { 255 char *p; 256 char *start; 257 258 if ((p = cdcomppath) == NULL) 259 return NULL; 260 start = cdcomppath; 261 while (*p != '/' && *p != '\0') 262 p++; 263 if (*p == '\0') { 264 cdcomppath = NULL; 265 } else { 266 *p++ = '\0'; 267 cdcomppath = p; 268 } 269 return start; 270 } 271 272 273 static char * 274 findcwd(char *dir) 275 { 276 char *new; 277 char *p; 278 279 /* 280 * If our argument is NULL, we don't know the current directory 281 * any more because we traversed a symbolic link or something 282 * we couldn't stat(). 283 */ 284 if (dir == NULL || curdir == NULL) 285 return getpwd2(); 286 cdcomppath = stalloc(strlen(dir) + 1); 287 scopy(dir, cdcomppath); 288 STARTSTACKSTR(new); 289 if (*dir != '/') { 290 STPUTS(curdir, new); 291 if (STTOPC(new) == '/') 292 STUNPUTC(new); 293 } 294 while ((p = getcomponent()) != NULL) { 295 if (equal(p, "..")) { 296 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 297 } else if (*p != '\0' && ! equal(p, ".")) { 298 STPUTC('/', new); 299 STPUTS(p, new); 300 } 301 } 302 if (new == stackblock()) 303 STPUTC('/', new); 304 STACKSTRNUL(new); 305 return stackblock(); 306 } 307 308 /* 309 * Update curdir (the name of the current directory) in response to a 310 * cd command. We also call hashcd to let the routines in exec.c know 311 * that the current directory has changed. 312 */ 313 static void 314 updatepwd(char *dir) 315 { 316 hashcd(); /* update command hash table */ 317 318 if (prevdir) 319 ckfree(prevdir); 320 prevdir = curdir; 321 curdir = dir ? savestr(dir) : NULL; 322 setvar("PWD", curdir, VEXPORT); 323 setvar("OLDPWD", prevdir, VEXPORT); 324 } 325 326 int 327 pwdcmd(int argc __unused, char **argv __unused) 328 { 329 char *p; 330 int ch, phys; 331 332 phys = Pflag; 333 while ((ch = nextopt("LP")) != '\0') { 334 switch (ch) { 335 case 'L': 336 phys = 0; 337 break; 338 case 'P': 339 phys = 1; 340 break; 341 } 342 } 343 344 if (*argptr != NULL) 345 error("too many arguments"); 346 347 if (!phys && getpwd()) { 348 out1str(curdir); 349 out1c('\n'); 350 } else { 351 if ((p = getpwd2()) == NULL) 352 error(".: %s", strerror(errno)); 353 out1str(p); 354 out1c('\n'); 355 } 356 357 return 0; 358 } 359 360 /* 361 * Get the current directory and cache the result in curdir. 362 */ 363 static char * 364 getpwd(void) 365 { 366 char *p; 367 368 if (curdir) 369 return curdir; 370 371 p = getpwd2(); 372 if (p != NULL) 373 curdir = savestr(p); 374 375 return curdir; 376 } 377 378 #define MAXPWD 256 379 380 /* 381 * Return the current directory. 382 */ 383 static char * 384 getpwd2(void) 385 { 386 char *pwd; 387 int i; 388 389 for (i = MAXPWD;; i *= 2) { 390 pwd = stalloc(i); 391 if (getcwd(pwd, i) != NULL) 392 return pwd; 393 stunalloc(pwd); 394 if (errno != ERANGE) 395 break; 396 } 397 398 return NULL; 399 } 400 401 /* 402 * Initialize PWD in a new shell. 403 * If the shell is interactive, we need to warn if this fails. 404 */ 405 void 406 pwd_init(int warn) 407 { 408 char *pwd; 409 struct stat stdot, stpwd; 410 411 pwd = lookupvar("PWD"); 412 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 413 stat(pwd, &stpwd) != -1 && 414 stdot.st_dev == stpwd.st_dev && 415 stdot.st_ino == stpwd.st_ino) { 416 if (curdir) 417 ckfree(curdir); 418 curdir = savestr(pwd); 419 } 420 if (getpwd() == NULL && warn) 421 out2fmt_flush("sh: cannot determine working directory\n"); 422 setvar("PWD", curdir, VEXPORT); 423 } 424