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 #include <sys/types.h> 34 #include <sys/stat.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 #include <errno.h> 39 #include <limits.h> 40 41 /* 42 * The cd and pwd commands. 43 */ 44 45 #include "shell.h" 46 #include "var.h" 47 #include "nodes.h" /* for jobs.h */ 48 #include "jobs.h" 49 #include "options.h" 50 #include "output.h" 51 #include "memalloc.h" 52 #include "error.h" 53 #include "exec.h" 54 #include "redir.h" 55 #include "mystring.h" 56 #include "show.h" 57 #include "cd.h" 58 #include "builtins.h" 59 60 static int cdlogical(char *); 61 static int cdphysical(char *); 62 static int docd(char *, int, int); 63 static char *getcomponent(char **); 64 static char *findcwd(char *); 65 static void updatepwd(char *); 66 static char *getpwd(void); 67 static char *getpwd2(void); 68 69 static char *curdir = NULL; /* current working directory */ 70 71 int 72 cdcmd(int argc __unused, char **argv __unused) 73 { 74 const char *dest; 75 const char *path; 76 char *p; 77 struct stat statb; 78 int ch, phys, print = 0, getcwderr = 0; 79 int rc; 80 int errno1 = ENOENT; 81 82 phys = Pflag; 83 while ((ch = nextopt("eLP")) != '\0') { 84 switch (ch) { 85 case 'e': 86 getcwderr = 1; 87 break; 88 case 'L': 89 phys = 0; 90 break; 91 case 'P': 92 phys = 1; 93 break; 94 } 95 } 96 97 if (*argptr != NULL && argptr[1] != NULL) 98 error("too many arguments"); 99 100 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 101 error("HOME not set"); 102 if (*dest == '\0') 103 dest = "."; 104 if (dest[0] == '-' && dest[1] == '\0') { 105 dest = bltinlookup("OLDPWD", 1); 106 if (dest == NULL) 107 error("OLDPWD not set"); 108 print = 1; 109 } 110 if (dest[0] == '/' || 111 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) || 112 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) || 113 (path = bltinlookup("CDPATH", 1)) == NULL) 114 path = ""; 115 while ((p = padvance(&path, NULL, dest)) != NULL) { 116 if (stat(p, &statb) < 0) { 117 if (errno != ENOENT) 118 errno1 = errno; 119 } else if (!S_ISDIR(statb.st_mode)) 120 errno1 = ENOTDIR; 121 else { 122 if (!print) { 123 /* 124 * XXX - rethink 125 */ 126 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 127 print = strcmp(p + 2, dest); 128 else 129 print = strcmp(p, dest); 130 } 131 rc = docd(p, print, phys); 132 if (rc >= 0) 133 return getcwderr ? rc : 0; 134 if (errno != ENOENT) 135 errno1 = errno; 136 } 137 } 138 error("%s: %s", dest, strerror(errno1)); 139 /*NOTREACHED*/ 140 return 0; 141 } 142 143 144 /* 145 * Actually change the directory. In an interactive shell, print the 146 * directory name if "print" is nonzero. 147 */ 148 static int 149 docd(char *dest, int print, int phys) 150 { 151 int rc; 152 153 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 154 155 /* If logical cd fails, fall back to physical. */ 156 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0) 157 return (-1); 158 159 if (print && iflag && curdir) { 160 out1fmt("%s\n", curdir); 161 /* 162 * Ignore write errors to preserve the invariant that the 163 * current directory is changed iff the exit status is 0 164 * (or 1 if -e was given and the full pathname could not be 165 * determined). 166 */ 167 flushout(out1); 168 outclearerror(out1); 169 } 170 171 return (rc); 172 } 173 174 static int 175 cdlogical(char *dest) 176 { 177 char *p; 178 char *q; 179 char *component; 180 char *path; 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 path = stsavestr(dest); 192 STARTSTACKSTR(p); 193 if (*dest == '/') { 194 STPUTC('/', p); 195 path++; 196 } 197 first = 1; 198 while ((q = getcomponent(&path)) != NULL) { 199 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 200 continue; 201 if (! first) 202 STPUTC('/', p); 203 first = 0; 204 component = q; 205 STPUTS(q, p); 206 if (equal(component, "..")) 207 continue; 208 STACKSTRNUL(p); 209 if (lstat(stackblock(), &statb) < 0) { 210 badstat = 1; 211 break; 212 } 213 } 214 215 INTOFF; 216 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) { 217 INTON; 218 return (-1); 219 } 220 updatepwd(p); 221 INTON; 222 return (0); 223 } 224 225 static int 226 cdphysical(char *dest) 227 { 228 char *p; 229 int rc = 0; 230 231 INTOFF; 232 if (chdir(dest) < 0) { 233 INTON; 234 return (-1); 235 } 236 p = findcwd(NULL); 237 if (p == NULL) { 238 warning("warning: failed to get name of current directory"); 239 rc = 1; 240 } 241 updatepwd(p); 242 INTON; 243 return (rc); 244 } 245 246 /* 247 * Get the next component of the path name pointed to by *path. 248 * This routine overwrites *path and the string pointed to by it. 249 */ 250 static char * 251 getcomponent(char **path) 252 { 253 char *p; 254 char *start; 255 256 if ((p = *path) == NULL) 257 return NULL; 258 start = *path; 259 while (*p != '/' && *p != '\0') 260 p++; 261 if (*p == '\0') { 262 *path = NULL; 263 } else { 264 *p++ = '\0'; 265 *path = p; 266 } 267 return start; 268 } 269 270 271 static char * 272 findcwd(char *dir) 273 { 274 char *new; 275 char *p; 276 char *path; 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 path = stsavestr(dir); 286 STARTSTACKSTR(new); 287 if (*dir != '/') { 288 STPUTS(curdir, new); 289 if (STTOPC(new) == '/') 290 STUNPUTC(new); 291 } 292 while ((p = getcomponent(&path)) != 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 char *prevdir; 315 316 hashcd(); /* update command hash table */ 317 318 setvar("PWD", dir, VEXPORT); 319 setvar("OLDPWD", curdir, VEXPORT); 320 prevdir = curdir; 321 curdir = dir ? savestr(dir) : NULL; 322 ckfree(prevdir); 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 INTOFF; 373 curdir = savestr(p); 374 INTON; 375 } 376 377 return curdir; 378 } 379 380 #define MAXPWD 256 381 382 /* 383 * Return the current directory. 384 */ 385 static char * 386 getpwd2(void) 387 { 388 char *pwd; 389 int i; 390 391 for (i = MAXPWD;; i *= 2) { 392 pwd = stalloc(i); 393 if (getcwd(pwd, i) != NULL) 394 return pwd; 395 stunalloc(pwd); 396 if (errno != ERANGE) 397 break; 398 } 399 400 return NULL; 401 } 402 403 /* 404 * Initialize PWD in a new shell. 405 * If the shell is interactive, we need to warn if this fails. 406 */ 407 void 408 pwd_init(int warn) 409 { 410 char *pwd; 411 struct stat stdot, stpwd; 412 413 pwd = lookupvar("PWD"); 414 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 415 stat(pwd, &stpwd) != -1 && 416 stdot.st_dev == stpwd.st_dev && 417 stdot.st_ino == stpwd.st_ino) { 418 if (curdir) 419 ckfree(curdir); 420 curdir = savestr(pwd); 421 } 422 if (getpwd() == NULL && warn) 423 out2fmt_flush("sh: cannot determine working directory\n"); 424 setvar("PWD", curdir, VEXPORT); 425 } 426