1 /* Copyright (C) 2007-2009 The Android Open Source Project 2 ** 3 ** This software is licensed under the terms of the GNU General Public 4 ** License version 2, as published by the Free Software Foundation, and 5 ** may be copied, distributed, and modified under those terms. 6 ** 7 ** This program is distributed in the hope that it will be useful, 8 ** but WITHOUT ANY WARRANTY; without even the implied warranty of 9 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 ** GNU General Public License for more details. 11 */ 12 #include "android/utils/debug.h" 13 #include "android/utils/eintr_wrapper.h" 14 #include "android/utils/path.h" 15 16 #include <stdio.h> 17 #include <string.h> 18 #include <stdlib.h> 19 #include <errno.h> 20 #include <fcntl.h> 21 22 #ifdef _WIN32 23 #include <process.h> 24 #include <shlobj.h> 25 #include <tlhelp32.h> 26 #include <io.h> 27 #include <sys/types.h> 28 #include <sys/stat.h> 29 #include <stdint.h> 30 #include <limits.h> 31 #include <winbase.h> 32 #else 33 #include <unistd.h> 34 #include <sys/stat.h> 35 #include <time.h> 36 #include <signal.h> 37 #endif 38 39 #define D(...) VERBOSE_PRINT(init,__VA_ARGS__) 40 41 /** PATH HANDLING ROUTINES 42 ** 43 ** path_parent() can be used to return the n-level parent of a given directory 44 ** this understands . and .. when encountered in the input path 45 **/ 46 47 static __inline__ int 48 ispathsep(int c) 49 { 50 #ifdef _WIN32 51 return (c == '/' || c == '\\'); 52 #else 53 return (c == '/'); 54 #endif 55 } 56 57 char* 58 path_parent( const char* path, int levels ) 59 { 60 const char* end = path + strlen(path); 61 char* result; 62 63 while (levels > 0) { 64 const char* base; 65 66 /* trim any trailing path separator */ 67 while (end > path && ispathsep(end[-1])) 68 end--; 69 70 base = end; 71 while (base > path && !ispathsep(base[-1])) 72 base--; 73 74 if (base <= path) { 75 if (end == base+1 && base[0] == '.' && levels == 1) 76 return strdup(".."); 77 /* we can't go that far */ 78 return NULL; 79 } 80 81 if (end == base+1 && base[0] == '.') 82 goto Next; 83 84 if (end == base+2 && base[0] == '.' && base[1] == '.') { 85 levels += 1; 86 goto Next; 87 } 88 89 levels -= 1; 90 91 Next: 92 end = base - 1; 93 } 94 result = malloc( end-path+1 ); 95 if (result != NULL) { 96 memcpy( result, path, end-path ); 97 result[end-path] = 0; 98 } 99 return result; 100 } 101 102 static char* 103 substring_dup( const char* start, const char* end ) 104 { 105 int len = end - start; 106 char* result = android_alloc(len+1); 107 memcpy(result, start, len); 108 result[len] = 0; 109 return result; 110 } 111 112 int 113 path_split( const char* path, char* *pdirname, char* *pbasename ) 114 { 115 const char* end = path + strlen(path); 116 const char* last; 117 char* basename; 118 119 /* prepare for errors */ 120 if (pdirname) 121 *pdirname = NULL; 122 if (pbasename) 123 *pbasename = NULL; 124 125 /* handle empty path case */ 126 if (end == path) { 127 return -1; 128 } 129 130 /* strip trailing path separators */ 131 while (end > path && ispathsep(end[-1])) 132 end -= 1; 133 134 /* handle "/" and degenerate cases like "////" */ 135 if (end == path) { 136 return -1; 137 } 138 139 /* find last separator */ 140 last = end; 141 while (last > path && !ispathsep(last[-1])) 142 last -= 1; 143 144 /* handle cases where there is no path separator */ 145 if (last == path) { 146 if (pdirname) 147 *pdirname = ASTRDUP("."); 148 if (pbasename) 149 *pbasename = substring_dup(path,end); 150 return 0; 151 } 152 153 /* handle "/foo" */ 154 if (last == path+1) { 155 if (pdirname) 156 *pdirname = ASTRDUP("/"); 157 if (pbasename) 158 *pbasename = substring_dup(path+1,end); 159 return 0; 160 } 161 162 /* compute basename */ 163 basename = substring_dup(last,end); 164 if (strcmp(basename, ".") == 0 || strcmp(basename, "..") == 0) { 165 AFREE(basename); 166 return -1; 167 } 168 169 if (pbasename) 170 *pbasename = basename; 171 else { 172 AFREE(basename); 173 } 174 175 /* compute dirname */ 176 if (pdirname != NULL) 177 *pdirname = substring_dup(path,last-1); 178 179 return 0; 180 } 181 182 char* 183 path_basename( const char* path ) 184 { 185 char* basename; 186 187 if (path_split(path, NULL, &basename) < 0) 188 return NULL; 189 190 return basename; 191 } 192 193 char* 194 path_dirname( const char* path ) 195 { 196 char* dirname; 197 198 if (path_split(path, &dirname, NULL) < 0) 199 return NULL; 200 201 return dirname; 202 } 203 204 205 206 207 208 /** MISC FILE AND DIRECTORY HANDLING 209 **/ 210 211 ABool 212 path_exists( const char* path ) 213 { 214 if (!path) 215 return 0; 216 217 int ret = HANDLE_EINTR(access(path, F_OK)); 218 return (ret == 0) || (errno != ENOENT); 219 } 220 221 /* checks that a path points to a regular file */ 222 ABool 223 path_is_regular( const char* path ) 224 { 225 if (path == NULL) 226 return 0; 227 228 struct stat st; 229 int ret = HANDLE_EINTR(stat(path, &st)); 230 if (ret < 0) 231 return 0; 232 233 return S_ISREG(st.st_mode); 234 } 235 236 237 /* checks that a path points to a directory */ 238 ABool 239 path_is_dir( const char* path ) 240 { 241 if (!path) 242 return 0; 243 244 struct stat st; 245 int ret = HANDLE_EINTR(stat(path, &st)); 246 if (ret < 0) 247 return 0; 248 249 return S_ISDIR(st.st_mode); 250 } 251 252 /* checks that one can read/write a given (regular) file */ 253 ABool 254 path_can_read( const char* path ) 255 { 256 if (!path) 257 return 0; 258 259 return HANDLE_EINTR(access(path, R_OK)) == 0; 260 } 261 262 ABool 263 path_can_write( const char* path ) 264 { 265 if (!path) 266 return 0; 267 268 return HANDLE_EINTR(access(path, W_OK)) == 0; 269 } 270 271 ABool 272 path_can_exec( const char* path ) 273 { 274 if (!path) 275 return 0; 276 277 return HANDLE_EINTR(access(path, X_OK)) == 0; 278 } 279 280 /* try to make a directory. returns 0 on success, -1 on failure 281 * (error code in errno) */ 282 APosixStatus 283 path_mkdir( const char* path, int mode ) 284 { 285 #ifdef _WIN32 286 (void)mode; 287 return mkdir(path); 288 #else 289 return HANDLE_EINTR(mkdir(path, mode)); 290 #endif 291 } 292 293 static APosixStatus 294 path_mkdir_recursive( char* path, unsigned len, int mode ) 295 { 296 char old_c; 297 int ret; 298 unsigned len2; 299 300 /* get rid of trailing separators */ 301 while (len > 0 && ispathsep(path[len-1])) 302 len -= 1; 303 304 if (len == 0) { 305 errno = ENOENT; 306 return -1; 307 } 308 309 /* check that the parent exists, 'len2' is the length of 310 * the parent part of the path */ 311 len2 = len-1; 312 while (len2 > 0 && !ispathsep(path[len2-1])) 313 len2 -= 1; 314 315 if (len2 > 0) { 316 old_c = path[len2]; 317 path[len2] = 0; 318 ret = 0; 319 if ( !path_exists(path) ) { 320 /* the parent doesn't exist, so try to create it */ 321 ret = path_mkdir_recursive( path, len2, mode ); 322 } 323 path[len2] = old_c; 324 325 if (ret < 0) 326 return ret; 327 } 328 329 /* at this point, we now the parent exists */ 330 old_c = path[len]; 331 path[len] = 0; 332 ret = path_mkdir( path, mode ); 333 path[len] = old_c; 334 335 return ret; 336 } 337 338 /* ensure that a given directory exists, create it if not, 339 0 on success, -1 on failure (error code in errno) */ 340 APosixStatus 341 path_mkdir_if_needed( const char* path, int mode ) 342 { 343 int ret = 0; 344 345 if (!path_exists(path)) { 346 ret = path_mkdir(path, mode); 347 348 if (ret < 0 && errno == ENOENT) { 349 char temp[MAX_PATH]; 350 unsigned len = (unsigned)strlen(path); 351 352 if (len > sizeof(temp)-1) { 353 errno = EINVAL; 354 return -1; 355 } 356 memcpy( temp, path, len ); 357 temp[len] = 0; 358 359 return path_mkdir_recursive(temp, len, mode); 360 } 361 } 362 return ret; 363 } 364 365 /* return the size of a given file in '*psize'. returns 0 on 366 * success, -1 on failure (error code in errno) */ 367 APosixStatus 368 path_get_size( const char* path, uint64_t *psize ) 369 { 370 #ifdef _WIN32 371 /* avoid _stat64 which is only defined in MSVCRT.DLL, not CRTDLL.DLL */ 372 /* do not use OpenFile() because it has strange search behaviour that could */ 373 /* result in getting the size of a different file */ 374 LARGE_INTEGER size; 375 HANDLE file = CreateFile( /* lpFilename */ path, 376 /* dwDesiredAccess */ GENERIC_READ, 377 /* dwSharedMode */ FILE_SHARE_READ|FILE_SHARE_WRITE, 378 /* lpSecurityAttributes */ NULL, 379 /* dwCreationDisposition */ OPEN_EXISTING, 380 /* dwFlagsAndAttributes */ 0, 381 /* hTemplateFile */ NULL ); 382 if (file == INVALID_HANDLE_VALUE) { 383 /* ok, just to play fair */ 384 errno = ENOENT; 385 return -1; 386 } 387 if (!GetFileSizeEx(file, &size)) { 388 /* maybe we tried to get the size of a pipe or something like that ? */ 389 *psize = 0; 390 } 391 else { 392 *psize = (uint64_t) size.QuadPart; 393 } 394 CloseHandle(file); 395 return 0; 396 #else 397 struct stat st; 398 int ret = HANDLE_EINTR(stat(path, &st)); 399 if (ret == 0) { 400 *psize = (uint64_t) st.st_size; 401 } 402 return ret; 403 #endif 404 } 405 406 407 ABool 408 path_is_absolute( const char* path ) 409 { 410 #ifdef _WIN32 411 if (path == NULL) 412 return 0; 413 414 if (path[0] == '/' || path[0] == '\\') 415 return 1; 416 417 /* 'C:' is always considered to be absolute 418 * even if used with a relative path like C:foo which 419 * is different from C:\foo 420 */ 421 if (path[0] != 0 && path[1] == ':') 422 return 1; 423 424 return 0; 425 #else 426 return (path != NULL && path[0] == '/'); 427 #endif 428 } 429 430 char* 431 path_get_absolute( const char* path ) 432 { 433 if (path_is_absolute(path)) { 434 return ASTRDUP(path); 435 } 436 437 #ifdef _WIN32 438 { 439 char* result; 440 int pathLen = strlen(path); 441 int currentLen = GetCurrentDirectory(0, NULL); 442 443 if (currentLen <= 0) { 444 /* Could not get size of working directory. something is 445 * really fishy here, return a simple copy */ 446 return ASTRDUP(path); 447 } 448 result = malloc(currentLen + pathLen + 2); 449 450 GetCurrentDirectory(currentLen+1, result); 451 if (currentLen == 0 || result[currentLen-1] != '\\') { 452 result[currentLen++] = '\\'; 453 } 454 memcpy(result + currentLen, path, pathLen+1); 455 456 return result; 457 } 458 #else 459 { 460 int pathLen = strlen(path); 461 char currentDir[PATH_MAX]; 462 int currentLen; 463 char* result; 464 465 if (getcwd(currentDir, sizeof(currentDir)) == NULL) { 466 /* Could not get the current working directory. something is really 467 * fishy here, so don't do anything and return a copy */ 468 return ASTRDUP(path); 469 } 470 471 /* Make a new path with <current-path>/<path> */ 472 currentLen = strlen(currentDir); 473 result = malloc(currentLen + pathLen + 2); 474 475 memcpy(result, currentDir, currentLen); 476 if (currentLen == 0 || result[currentLen-1] != '/') { 477 result[currentLen++] = '/'; 478 } 479 memcpy(result + currentLen, path, pathLen+1); 480 481 return result; 482 } 483 #endif 484 } 485 486 /** OTHER FILE UTILITIES 487 ** 488 ** path_empty_file() creates an empty file at a given path location. 489 ** if the file already exists, it is truncated without warning 490 ** 491 ** path_copy_file() copies one file into another. 492 ** 493 ** both functions return 0 on success, and -1 on error 494 **/ 495 496 APosixStatus 497 path_empty_file( const char* path ) 498 { 499 #ifdef _WIN32 500 int fd = _creat( path, S_IWRITE ); 501 #else 502 /* on Unix, only allow the owner to read/write, since the file * 503 * may contain some personal data we don't want to see exposed */ 504 int fd = creat(path, S_IRUSR | S_IWUSR); 505 #endif 506 if (fd >= 0) { 507 close(fd); 508 return 0; 509 } 510 return -1; 511 } 512 513 APosixStatus 514 path_copy_file( const char* dest, const char* source ) 515 { 516 int fd, fs, result = -1; 517 518 /* if the destination doesn't exist, create it */ 519 if ( access(source, F_OK) < 0 || 520 path_empty_file(dest) < 0) { 521 return -1; 522 } 523 524 if ( access(source, R_OK) < 0 ) { 525 D("%s: source file is un-readable: %s\n", 526 __FUNCTION__, source); 527 return -1; 528 } 529 530 #ifdef _WIN32 531 fd = _open(dest, _O_RDWR | _O_BINARY); 532 fs = _open(source, _O_RDONLY | _O_BINARY); 533 #else 534 fd = creat(dest, S_IRUSR | S_IWUSR); 535 fs = open(source, S_IREAD); 536 #endif 537 if (fs >= 0 && fd >= 0) { 538 char buf[4096]; 539 ssize_t total = 0; 540 ssize_t n; 541 result = 0; /* success */ 542 while ((n = read(fs, buf, 4096)) > 0) { 543 if (write(fd, buf, n) != n) { 544 /* write failed. Make it return -1 so that an 545 * empty file be created. */ 546 D("Failed to copy '%s' to '%s': %s (%d)", 547 source, dest, strerror(errno), errno); 548 result = -1; 549 break; 550 } 551 total += n; 552 } 553 } 554 555 if (fs >= 0) { 556 close(fs); 557 } 558 if (fd >= 0) { 559 close(fd); 560 } 561 return result; 562 } 563 564 565 APosixStatus 566 path_delete_file( const char* path ) 567 { 568 #ifdef _WIN32 569 int ret = _unlink( path ); 570 if (ret == -1 && errno == EACCES) { 571 /* a first call to _unlink will fail if the file is set read-only */ 572 /* we can however try to change its mode first and call unlink */ 573 /* again... */ 574 ret = _chmod( path, _S_IREAD | _S_IWRITE ); 575 if (ret == 0) 576 ret = _unlink( path ); 577 } 578 return ret; 579 #else 580 return unlink(path); 581 #endif 582 } 583 584 585 void* 586 path_load_file(const char *fn, size_t *pSize) 587 { 588 char* data; 589 int sz; 590 int fd; 591 592 if (pSize) 593 *pSize = 0; 594 595 data = NULL; 596 597 fd = open(fn, O_BINARY | O_RDONLY); 598 if(fd < 0) return NULL; 599 600 do { 601 sz = lseek(fd, 0, SEEK_END); 602 if(sz < 0) break; 603 604 if (pSize) 605 *pSize = (size_t) sz; 606 607 if (lseek(fd, 0, SEEK_SET) != 0) 608 break; 609 610 data = (char*) malloc(sz + 1); 611 if(data == NULL) break; 612 613 if (read(fd, data, sz) != sz) 614 break; 615 616 close(fd); 617 data[sz] = 0; 618 619 return data; 620 } while (0); 621 622 close(fd); 623 624 if(data != NULL) 625 free(data); 626 627 return NULL; 628 } 629 630 #ifdef _WIN32 631 # define DIR_SEP ';' 632 #else 633 # define DIR_SEP ':' 634 #endif 635 636 char* 637 path_search_exec( const char* filename ) 638 { 639 const char* sysPath = getenv("PATH"); 640 char temp[PATH_MAX]; 641 const char* p; 642 643 /* If the file contains a directory separator, don't search */ 644 #ifdef _WIN32 645 if (strchr(filename, '/') != NULL || strchr(filename, '\\') != NULL) { 646 #else 647 if (strchr(filename, '/') != NULL) { 648 #endif 649 if (path_exists(filename)) { 650 return strdup(filename); 651 } else { 652 return NULL; 653 } 654 } 655 656 /* If system path is empty, don't search */ 657 if (sysPath == NULL || sysPath[0] == '\0') { 658 return NULL; 659 } 660 661 /* Count the number of non-empty items in the system path 662 * Items are separated by DIR_SEP, and two successive separators 663 * correspond to an empty item that will be ignored. 664 * Also compute the required string storage length. */ 665 p = sysPath; 666 667 while (*p) { 668 char* p2 = strchr(p, DIR_SEP); 669 int len; 670 if (p2 == NULL) { 671 len = strlen(p); 672 } else { 673 len = p2 - p; 674 } 675 676 do { 677 if (len <= 0) 678 break; 679 680 snprintf(temp, sizeof(temp), "%.*s/%s", len, p, filename); 681 682 if (path_exists(temp) && path_can_exec(temp)) { 683 return strdup(temp); 684 } 685 686 } while (0); 687 688 p += len; 689 if (*p == DIR_SEP) 690 p++; 691 } 692 693 /* Nothing, really */ 694 return NULL; 695 } 696