base/file_util_posix.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/file_util.h"
   6
   7 #include <dirent.h>
   8 #include <errno.h>
   9 #include <fcntl.h>
  10 #include <fnmatch.h>
  11 #include <libgen.h>
  12 #include <limits.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <sys/errno.h>
  17 #include <sys/mman.h>
  18 #include <sys/param.h>
  19 #include <sys/stat.h>
  20 #include <sys/time.h>
  21 #include <sys/types.h>
  22 #include <time.h>
  23 #include <unistd.h>
  24
  25 #if defined(OS_MACOSX)
  26 #include <AvailabilityMacros.h>
  27 #include "base/mac/foundation_util.h"
  28 #elif !defined(OS_ANDROID)
  29 #include <glib.h>
  30 #endif
  31
  32 #include <fstream>
  33
  34 #include "base/basictypes.h"
  35 #include "base/eintr_wrapper.h"
  36 #include "base/file_path.h"
  37 #include "base/logging.h"
  38 #include "base/memory/scoped_ptr.h"
  39 #include "base/memory/singleton.h"
  40 #include "base/string_util.h"
  41 #include "base/stringprintf.h"
  42 #include "base/sys_string_conversions.h"
  43 #include "base/threading/thread_restrictions.h"
  44 #include "base/time.h"
  45 #include "base/utf_string_conversions.h"
  46
  47 #if defined(OS_ANDROID)
  48 #include "base/os_compat_android.h"
  49 #endif
  50
  51 namespace file_util {
  52
  53 namespace {
  54
  55 // Helper for NormalizeFilePath(), defined below.
  56 bool RealPath(const FilePath& path, FilePath* real_path) {
  57   base::ThreadRestrictions::AssertIOAllowed();  // For realpath().
  58   FilePath::CharType buf[PATH_MAX];
  59   if (!realpath(path.value().c_str(), buf))
  60     return false;
  61
  62   *real_path = FilePath(buf);
  63   return true;
  64 }
  65
  66 }  // namespace
  67
  68 #if defined(OS_OPENBSD) || defined(OS_FREEBSD) || \
  69     (defined(OS_MACOSX) && \
  70      MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5)
  71 typedef struct stat stat_wrapper_t;
  72 static int CallStat(const char *path, stat_wrapper_t *sb) {
  73   base::ThreadRestrictions::AssertIOAllowed();
  74   return stat(path, sb);
  75 }
  76 #else
  77 typedef struct stat64 stat_wrapper_t;
  78 static int CallStat(const char *path, stat_wrapper_t *sb) {
  79   base::ThreadRestrictions::AssertIOAllowed();
  80   return stat64(path, sb);
  81 }
  82 #endif
  83
  84 static std::string TempFileName() {
  85 #if defined(OS_MACOSX)
  86   return StringPrintf(".%s.XXXXXX", base::mac::BaseBundleID());
  87 #endif
  88
  89 #if defined(GOOGLE_CHROME_BUILD)
  90   return std::string(".com.google.Chrome.XXXXXX");
  91 #else
  92   return std::string(".org.chromium.Chromium.XXXXXX");
  93 #endif
  94 }
  95
  96 bool AbsolutePath(FilePath* path) {
  97   base::ThreadRestrictions::AssertIOAllowed();  // For realpath().
  98   char full_path[PATH_MAX];
  99   if (realpath(path->value().c_str(), full_path) == NULL)
 100     return false;
 101   *path = FilePath(full_path);
 102   return true;
 103 }
 104
 105 int CountFilesCreatedAfter(const FilePath& path,
 106                            const base::Time& comparison_time) {
 107   base::ThreadRestrictions::AssertIOAllowed();
 108   int file_count = 0;
 109
 110   DIR* dir = opendir(path.value().c_str());
 111   if (dir) {
 112 #if !defined(OS_LINUX) && !defined(OS_MACOSX) && !defined(OS_FREEBSD) && \
 113     !defined(OS_OPENBSD) && !defined(OS_SOLARIS) && !defined(OS_ANDROID)
 114   #error Port warning: depending on the definition of struct dirent, \
 115          additional space for pathname may be needed
 116 #endif
 117     struct dirent ent_buf;
 118     struct dirent* ent;
 119     while (readdir_r(dir, &ent_buf, &ent) == 0 && ent) {
 120       if ((strcmp(ent->d_name, ".") == 0) ||
 121           (strcmp(ent->d_name, "..") == 0))
 122         continue;
 123
 124       stat_wrapper_t st;
 125       int test = CallStat(path.Append(ent->d_name).value().c_str(), &st);
 126       if (test != 0) {
 127         PLOG(ERROR) << "stat64 failed";
 128         continue;
 129       }
 130       // Here, we use Time::TimeT(), which discards microseconds. This
 131       // means that files which are newer than |comparison_time| may
 132       // be considered older. If we don't discard microseconds, it
 133       // introduces another issue. Suppose the following case:
 134       //
 135       // 1. Get |comparison_time| by Time::Now() and the value is 10.1 (secs).
 136       // 2. Create a file and the current time is 10.3 (secs).
 137       //
 138       // As POSIX doesn't have microsecond precision for |st_ctime|,
 139       // the creation time of the file created in the step 2 is 10 and
 140       // the file is considered older than |comparison_time|. After
 141       // all, we may have to accept either of the two issues: 1. files
 142       // which are older than |comparison_time| are considered newer
 143       // (current implementation) 2. files newer than
 144       // |comparison_time| are considered older.
 145       if (static_cast<time_t>(st.st_ctime) >= comparison_time.ToTimeT())
 146         ++file_count;
 147     }
 148     closedir(dir);
 149   }
 150   return file_count;
 151 }
 152
 153 // TODO(erikkay): The Windows version of this accepts paths like "foo/bar/*"
 154 // which works both with and without the recursive flag.  I'm not sure we need
 155 // that functionality. If not, remove from file_util_win.cc, otherwise add it
 156 // here.
 157 bool Delete(const FilePath& path, bool recursive) {
 158   base::ThreadRestrictions::AssertIOAllowed();
 159   const char* path_str = path.value().c_str();
 160   stat_wrapper_t file_info;
 161   int test = CallStat(path_str, &file_info);
 162   if (test != 0) {
 163     // The Windows version defines this condition as success.
 164     bool ret = (errno == ENOENT || errno == ENOTDIR);
 165     return ret;
 166   }
 167   if (!S_ISDIR(file_info.st_mode))
 168     return (unlink(path_str) == 0);
 169   if (!recursive)
 170     return (rmdir(path_str) == 0);
 171
 172   bool success = true;
 173   std::stack<std::string> directories;
 174   directories.push(path.value());
 175   FileEnumerator traversal(path, true, static_cast<FileEnumerator::FILE_TYPE>(
 176         FileEnumerator::FILES | FileEnumerator::DIRECTORIES |
 177         FileEnumerator::SHOW_SYM_LINKS));
 178   for (FilePath current = traversal.Next(); success && !current.empty();
 179        current = traversal.Next()) {
 180     FileEnumerator::FindInfo info;
 181     traversal.GetFindInfo(&info);
 182
 183     if (S_ISDIR(info.stat.st_mode))
 184       directories.push(current.value());
 185     else
 186       success = (unlink(current.value().c_str()) == 0);
 187   }
 188
 189   while (success && !directories.empty()) {
 190     FilePath dir = FilePath(directories.top());
 191     directories.pop();
 192     success = (rmdir(dir.value().c_str()) == 0);
 193   }
 194   return success;
 195 }
 196
 197 bool Move(const FilePath& from_path, const FilePath& to_path) {
 198   base::ThreadRestrictions::AssertIOAllowed();
 199   // Windows compatibility: if to_path exists, from_path and to_path
 200   // must be the same type, either both files, or both directories.
 201   stat_wrapper_t to_file_info;
 202   if (CallStat(to_path.value().c_str(), &to_file_info) == 0) {
 203     stat_wrapper_t from_file_info;
 204     if (CallStat(from_path.value().c_str(), &from_file_info) == 0) {
 205       if (S_ISDIR(to_file_info.st_mode) != S_ISDIR(from_file_info.st_mode))
 206         return false;
 207     } else {
 208       return false;
 209     }
 210   }
 211
 212   if (rename(from_path.value().c_str(), to_path.value().c_str()) == 0)
 213     return true;
 214
 215   if (!CopyDirectory(from_path, to_path, true))
 216     return false;
 217
 218   Delete(from_path, true);
 219   return true;
 220 }
 221
 222 bool ReplaceFile(const FilePath& from_path, const FilePath& to_path) {
 223   base::ThreadRestrictions::AssertIOAllowed();
 224   return (rename(from_path.value().c_str(), to_path.value().c_str()) == 0);
 225 }
 226
 227 bool CopyDirectory(const FilePath& from_path,
 228                    const FilePath& to_path,
 229                    bool recursive) {
 230   base::ThreadRestrictions::AssertIOAllowed();
 231   // Some old callers of CopyDirectory want it to support wildcards.
 232   // After some discussion, we decided to fix those callers.
 233   // Break loudly here if anyone tries to do this.
 234   // TODO(evanm): remove this once we're sure it's ok.
 235   DCHECK(to_path.value().find('*') == std::string::npos);
 236   DCHECK(from_path.value().find('*') == std::string::npos);
 237
 238   char top_dir[PATH_MAX];
 239   if (base::strlcpy(top_dir, from_path.value().c_str(),
 240                     arraysize(top_dir)) >= arraysize(top_dir)) {
 241     return false;
 242   }
 243
 244   // This function does not properly handle destinations within the source
 245   FilePath real_to_path = to_path;
 246   if (PathExists(real_to_path)) {
 247     if (!AbsolutePath(&real_to_path))
 248       return false;
 249   } else {
 250     real_to_path = real_to_path.DirName();
 251     if (!AbsolutePath(&real_to_path))
 252       return false;
 253   }
 254   FilePath real_from_path = from_path;
 255   if (!AbsolutePath(&real_from_path))
 256     return false;
 257   if (real_to_path.value().size() >= real_from_path.value().size() &&
 258       real_to_path.value().compare(0, real_from_path.value().size(),
 259       real_from_path.value()) == 0)
 260     return false;
 261
 262   bool success = true;
 263   FileEnumerator::FILE_TYPE traverse_type =
 264       static_cast<FileEnumerator::FILE_TYPE>(FileEnumerator::FILES |
 265       FileEnumerator::SHOW_SYM_LINKS);
 266   if (recursive)
 267     traverse_type = static_cast<FileEnumerator::FILE_TYPE>(
 268         traverse_type | FileEnumerator::DIRECTORIES);
 269   FileEnumerator traversal(from_path, recursive, traverse_type);
 270
 271   // We have to mimic windows behavior here. |to_path| may not exist yet,
 272   // start the loop with |to_path|.
 273   FileEnumerator::FindInfo info;
 274   FilePath current = from_path;
 275   if (stat(from_path.value().c_str(), &info.stat) < 0) {
 276     LOG(ERROR) << "CopyDirectory() couldn't stat source directory: " <<
 277         from_path.value() << " errno = " << errno;
 278     success = false;
 279   }
 280   struct stat to_path_stat;
 281   FilePath from_path_base = from_path;
 282   if (recursive && stat(to_path.value().c_str(), &to_path_stat) == 0 &&
 283       S_ISDIR(to_path_stat.st_mode)) {
 284     // If the destination already exists and is a directory, then the
 285     // top level of source needs to be copied.
 286     from_path_base = from_path.DirName();
 287   }
 288
 289   // The Windows version of this function assumes that non-recursive calls
 290   // will always have a directory for from_path.
 291   DCHECK(recursive || S_ISDIR(info.stat.st_mode));
 292
 293   while (success && !current.empty()) {
 294     // current is the source path, including from_path, so paste
 295     // the suffix after from_path onto to_path to create the target_path.
 296     std::string suffix(&current.value().c_str()[from_path_base.value().size()]);
 297     // Strip the leading '/' (if any).
 298     if (!suffix.empty()) {
 299       DCHECK_EQ('/', suffix[0]);
 300       suffix.erase(0, 1);
 301     }
 302     const FilePath target_path = to_path.Append(suffix);
 303
 304     if (S_ISDIR(info.stat.st_mode)) {
 305       if (mkdir(target_path.value().c_str(), info.stat.st_mode & 01777) != 0 &&
 306           errno != EEXIST) {
 307         LOG(ERROR) << "CopyDirectory() couldn't create directory: " <<
 308             target_path.value() << " errno = " << errno;
 309         success = false;
 310       }
 311     } else if (S_ISREG(info.stat.st_mode)) {
 312       if (!CopyFile(current, target_path)) {
 313         LOG(ERROR) << "CopyDirectory() couldn't create file: " <<
 314             target_path.value();
 315         success = false;
 316       }
 317     } else {
 318       LOG(WARNING) << "CopyDirectory() skipping non-regular file: " <<
 319           current.value();
 320     }
 321
 322     current = traversal.Next();
 323     traversal.GetFindInfo(&info);
 324   }
 325
 326   return success;
 327 }
 328
 329 bool PathExists(const FilePath& path) {
 330   base::ThreadRestrictions::AssertIOAllowed();
 331   return access(path.value().c_str(), F_OK) == 0;
 332 }
 333
 334 bool PathIsWritable(const FilePath& path) {
 335   base::ThreadRestrictions::AssertIOAllowed();
 336   return access(path.value().c_str(), W_OK) == 0;
 337 }
 338
 339 bool DirectoryExists(const FilePath& path) {
 340   base::ThreadRestrictions::AssertIOAllowed();
 341   stat_wrapper_t file_info;
 342   if (CallStat(path.value().c_str(), &file_info) == 0)
 343     return S_ISDIR(file_info.st_mode);
 344   return false;
 345 }
 346
 347 // TODO(erikkay): implement
 348 #if 0
 349 bool GetFileCreationLocalTimeFromHandle(int fd,
 350                                         LPSYSTEMTIME creation_time) {
 351   if (!file_handle)
 352     return false;
 353
 354   FILETIME utc_filetime;
 355   if (!GetFileTime(file_handle, &utc_filetime, NULL, NULL))
 356     return false;
 357
 358   FILETIME local_filetime;
 359   if (!FileTimeToLocalFileTime(&utc_filetime, &local_filetime))
 360     return false;
 361
 362   return !!FileTimeToSystemTime(&local_filetime, creation_time);
 363 }
 364
 365 bool GetFileCreationLocalTime(const std::string& filename,
 366                               LPSYSTEMTIME creation_time) {
 367   ScopedHandle file_handle(
 368       CreateFile(filename.c_str(), GENERIC_READ,
 369                  FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
 370                  OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL));
 371   return GetFileCreationLocalTimeFromHandle(file_handle.Get(), creation_time);
 372 }
 373 #endif
 374
 375 bool ReadFromFD(int fd, char* buffer, size_t bytes) {
 376   size_t total_read = 0;
 377   while (total_read < bytes) {
 378     ssize_t bytes_read =
 379         HANDLE_EINTR(read(fd, buffer + total_read, bytes - total_read));
 380     if (bytes_read <= 0)
 381       break;
 382     total_read += bytes_read;
 383   }
 384   return total_read == bytes;
 385 }
 386
 387 bool CreateSymbolicLink(const FilePath& target_path,
 388                         const FilePath& symlink_path) {
 389   DCHECK(!symlink_path.empty());
 390   DCHECK(!target_path.empty());
 391   return ::symlink(target_path.value().c_str(),
 392                    symlink_path.value().c_str()) != -1;
 393 }
 394
 395 bool ReadSymbolicLink(const FilePath& symlink_path,
 396                       FilePath* target_path) {
 397   DCHECK(!symlink_path.empty());
 398   DCHECK(target_path);
 399   char buf[PATH_MAX];
 400   ssize_t count = ::readlink(symlink_path.value().c_str(), buf, arraysize(buf));
 401
 402   if (count <= 0) {
 403     target_path->clear();
 404     return false;
 405   }
 406
 407   *target_path = FilePath(FilePath::StringType(buf, count));
 408   return true;
 409 }
 410
 411 // Creates and opens a temporary file in |directory|, returning the
 412 // file descriptor. |path| is set to the temporary file path.
 413 // This function does NOT unlink() the file.
 414 int CreateAndOpenFdForTemporaryFile(FilePath directory, FilePath* path) {
 415   base::ThreadRestrictions::AssertIOAllowed();  // For call to mkstemp().
 416   *path = directory.Append(TempFileName());
 417   const std::string& tmpdir_string = path->value();
 418   // this should be OK since mkstemp just replaces characters in place
 419   char* buffer = const_cast<char*>(tmpdir_string.c_str());
 420
 421   return HANDLE_EINTR(mkstemp(buffer));
 422 }
 423
 424 bool CreateTemporaryFile(FilePath* path) {
 425   base::ThreadRestrictions::AssertIOAllowed();  // For call to close().
 426   FilePath directory;
 427   if (!GetTempDir(&directory))
 428     return false;
 429   int fd = CreateAndOpenFdForTemporaryFile(directory, path);
 430   if (fd < 0)
 431     return false;
 432   ignore_result(HANDLE_EINTR(close(fd)));
 433   return true;
 434 }
 435
 436 FILE* CreateAndOpenTemporaryShmemFile(FilePath* path) {
 437   FilePath directory;
 438   if (!GetShmemTempDir(&directory))
 439     return NULL;
 440
 441   return CreateAndOpenTemporaryFileInDir(directory, path);
 442 }
 443
 444 FILE* CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* path) {
 445   int fd = CreateAndOpenFdForTemporaryFile(dir, path);
 446   if (fd < 0)
 447     return NULL;
 448
 449   FILE* file = fdopen(fd, "a+");
 450   if (!file)
 451     ignore_result(HANDLE_EINTR(close(fd)));
 452   return file;
 453 }
 454
 455 bool CreateTemporaryFileInDir(const FilePath& dir, FilePath* temp_file) {
 456   base::ThreadRestrictions::AssertIOAllowed();  // For call to close().
 457   int fd = CreateAndOpenFdForTemporaryFile(dir, temp_file);
 458   return ((fd >= 0) && !HANDLE_EINTR(close(fd)));
 459 }
 460
 461 static bool CreateTemporaryDirInDirImpl(const FilePath& base_dir,
 462                                         const FilePath::StringType& name_tmpl,
 463                                         FilePath* new_dir) {
 464   base::ThreadRestrictions::AssertIOAllowed();  // For call to mkdtemp().
 465   CHECK(name_tmpl.find("XXXXXX") != FilePath::StringType::npos)
 466     << "Directory name template must contain \"XXXXXX\".";
 467
 468   FilePath sub_dir = base_dir.Append(name_tmpl);
 469   std::string sub_dir_string = sub_dir.value();
 470
 471   // this should be OK since mkdtemp just replaces characters in place
 472   char* buffer = const_cast<char*>(sub_dir_string.c_str());
 473   char* dtemp = mkdtemp(buffer);
 474   if (!dtemp) {
 475     DPLOG(ERROR) << "mkdtemp";
 476     return false;
 477   }
 478   *new_dir = FilePath(dtemp);
 479   return true;
 480 }
 481
 482 bool CreateTemporaryDirInDir(const FilePath& base_dir,
 483                              const FilePath::StringType& prefix,
 484                              FilePath* new_dir) {
 485   FilePath::StringType mkdtemp_template = prefix;
 486   mkdtemp_template.append(FILE_PATH_LITERAL("XXXXXX"));
 487   return CreateTemporaryDirInDirImpl(base_dir, mkdtemp_template, new_dir);
 488 }
 489
 490 bool CreateNewTempDirectory(const FilePath::StringType& prefix,
 491                             FilePath* new_temp_path) {
 492   FilePath tmpdir;
 493   if (!GetTempDir(&tmpdir))
 494     return false;
 495
 496   return CreateTemporaryDirInDirImpl(tmpdir, TempFileName(), new_temp_path);
 497 }
 498
 499 bool CreateDirectory(const FilePath& full_path) {
 500   base::ThreadRestrictions::AssertIOAllowed();  // For call to mkdir().
 501   std::vector<FilePath> subpaths;
 502
 503   // Collect a list of all parent directories.
 504   FilePath last_path = full_path;
 505   subpaths.push_back(full_path);
 506   for (FilePath path = full_path.DirName();
 507        path.value() != last_path.value(); path = path.DirName()) {
 508     subpaths.push_back(path);
 509     last_path = path;
 510   }
 511
 512   // Iterate through the parents and create the missing ones.
 513   for (std::vector<FilePath>::reverse_iterator i = subpaths.rbegin();
 514        i != subpaths.rend(); ++i) {
 515     if (DirectoryExists(*i))
 516       continue;
 517     if (mkdir(i->value().c_str(), 0700) == 0)
 518       continue;
 519     // Mkdir failed, but it might have failed with EEXIST, or some other error
 520     // due to the the directory appearing out of thin air. This can occur if
 521     // two processes are trying to create the same file system tree at the same
 522     // time. Check to see if it exists and make sure it is a directory.
 523     if (!DirectoryExists(*i))
 524       return false;
 525   }
 526   return true;
 527 }
 528
 529 // TODO(rkc): Refactor GetFileInfo and FileEnumerator to handle symlinks
 530 // correctly. http://code.google.com/p/chromium-os/issues/detail?id=15948
 531 bool IsLink(const FilePath& file_path) {
 532   struct stat st;
 533   // If we can't lstat the file, it's safe to assume that the file won't at
 534   // least be a 'followable' link.
 535   if (lstat(file_path.value().c_str(), &st) != 0)
 536     return false;
 537
 538   if (S_ISLNK(st.st_mode))
 539     return true;
 540   else
 541     return false;
 542 }
 543
 544 bool GetFileInfo(const FilePath& file_path, base::PlatformFileInfo* results) {
 545   stat_wrapper_t file_info;
 546   if (CallStat(file_path.value().c_str(), &file_info) != 0)
 547     return false;
 548   results->is_directory = S_ISDIR(file_info.st_mode);
 549   results->size = file_info.st_size;
 550   results->last_modified = base::Time::FromTimeT(file_info.st_mtime);
 551   results->last_accessed = base::Time::FromTimeT(file_info.st_atime);
 552   results->creation_time = base::Time::FromTimeT(file_info.st_ctime);
 553   return true;
 554 }
 555
 556 bool GetInode(const FilePath& path, ino_t* inode) {
 557   base::ThreadRestrictions::AssertIOAllowed();  // For call to stat().
 558   struct stat buffer;
 559   int result = stat(path.value().c_str(), &buffer);
 560   if (result < 0)
 561     return false;
 562
 563   *inode = buffer.st_ino;
 564   return true;
 565 }
 566
 567 FILE* OpenFile(const std::string& filename, const char* mode) {
 568   return OpenFile(FilePath(filename), mode);
 569 }
 570
 571 FILE* OpenFile(const FilePath& filename, const char* mode) {
 572   base::ThreadRestrictions::AssertIOAllowed();
 573   FILE* result = NULL;
 574   do {
 575     result = fopen(filename.value().c_str(), mode);
 576   } while (!result && errno == EINTR);
 577   return result;
 578 }
 579
 580 int ReadFile(const FilePath& filename, char* data, int size) {
 581   base::ThreadRestrictions::AssertIOAllowed();
 582   int fd = HANDLE_EINTR(open(filename.value().c_str(), O_RDONLY));
 583   if (fd < 0)
 584     return -1;
 585
 586   ssize_t bytes_read = HANDLE_EINTR(read(fd, data, size));
 587   if (int ret = HANDLE_EINTR(close(fd)) < 0)
 588     return ret;
 589   return bytes_read;
 590 }
 591
 592 int WriteFile(const FilePath& filename, const char* data, int size) {
 593   base::ThreadRestrictions::AssertIOAllowed();
 594   int fd = HANDLE_EINTR(creat(filename.value().c_str(), 0666));
 595   if (fd < 0)
 596     return -1;
 597
 598   int bytes_written = WriteFileDescriptor(fd, data, size);
 599   if (int ret = HANDLE_EINTR(close(fd)) < 0)
 600     return ret;
 601   return bytes_written;
 602 }
 603
 604 int WriteFileDescriptor(const int fd, const char* data, int size) {
 605   // Allow for partial writes.
 606   ssize_t bytes_written_total = 0;
 607   for (ssize_t bytes_written_partial = 0; bytes_written_total < size;
 608        bytes_written_total += bytes_written_partial) {
 609     bytes_written_partial =
 610         HANDLE_EINTR(write(fd, data + bytes_written_total,
 611                            size - bytes_written_total));
 612     if (bytes_written_partial < 0)
 613       return -1;
 614   }
 615
 616   return bytes_written_total;
 617 }
 618
 619 // Gets the current working directory for the process.
 620 bool GetCurrentDirectory(FilePath* dir) {
 621   // getcwd can return ENOENT, which implies it checks against the disk.
 622   base::ThreadRestrictions::AssertIOAllowed();
 623
 624   char system_buffer[PATH_MAX] = "";
 625   if (!getcwd(system_buffer, sizeof(system_buffer))) {
 626     NOTREACHED();
 627     return false;
 628   }
 629   *dir = FilePath(system_buffer);
 630   return true;
 631 }
 632
 633 // Sets the current working directory for the process.
 634 bool SetCurrentDirectory(const FilePath& path) {
 635   base::ThreadRestrictions::AssertIOAllowed();
 636   int ret = chdir(path.value().c_str());
 637   return !ret;
 638 }
 639
 640 ///////////////////////////////////////////////
 641 // FileEnumerator
 642
 643 FileEnumerator::FileEnumerator(const FilePath& root_path,
 644                                bool recursive,
 645                                FileEnumerator::FILE_TYPE file_type)
 646     : current_directory_entry_(0),
 647       root_path_(root_path),
 648       recursive_(recursive),
 649       file_type_(file_type) {
 650   // INCLUDE_DOT_DOT must not be specified if recursive.
 651   DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
 652   pending_paths_.push(root_path);
 653 }
 654
 655 FileEnumerator::FileEnumerator(const FilePath& root_path,
 656                                bool recursive,
 657                                FileEnumerator::FILE_TYPE file_type,
 658                                const FilePath::StringType& pattern)
 659     : current_directory_entry_(0),
 660       root_path_(root_path),
 661       recursive_(recursive),
 662       file_type_(file_type),
 663       pattern_(root_path.Append(pattern).value()) {
 664   // INCLUDE_DOT_DOT must not be specified if recursive.
 665   DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
 666   // The Windows version of this code appends the pattern to the root_path,
 667   // potentially only matching against items in the top-most directory.
 668   // Do the same here.
 669   if (pattern.empty())
 670     pattern_ = FilePath::StringType();
 671   pending_paths_.push(root_path);
 672 }
 673
 674 FileEnumerator::~FileEnumerator() {
 675 }
 676
 677 FilePath FileEnumerator::Next() {
 678   ++current_directory_entry_;
 679
 680   // While we've exhausted the entries in the current directory, do the next
 681   while (current_directory_entry_ >= directory_entries_.size()) {
 682     if (pending_paths_.empty())
 683       return FilePath();
 684
 685     root_path_ = pending_paths_.top();
 686     root_path_ = root_path_.StripTrailingSeparators();
 687     pending_paths_.pop();
 688
 689     std::vector<DirectoryEntryInfo> entries;
 690     if (!ReadDirectory(&entries, root_path_, file_type_ & SHOW_SYM_LINKS))
 691       continue;
 692
 693     directory_entries_.clear();
 694     current_directory_entry_ = 0;
 695     for (std::vector<DirectoryEntryInfo>::const_iterator
 696         i = entries.begin(); i != entries.end(); ++i) {
 697       FilePath full_path = root_path_.Append(i->filename);
 698       if (ShouldSkip(full_path))
 699         continue;
 700
 701       if (pattern_.size() &&
 702           fnmatch(pattern_.c_str(), full_path.value().c_str(), FNM_NOESCAPE))
 703         continue;
 704
 705       if (recursive_ && S_ISDIR(i->stat.st_mode))
 706         pending_paths_.push(full_path);
 707
 708       if ((S_ISDIR(i->stat.st_mode) && (file_type_ & DIRECTORIES)) ||
 709           (!S_ISDIR(i->stat.st_mode) && (file_type_ & FILES)))
 710         directory_entries_.push_back(*i);
 711     }
 712   }
 713
 714   return root_path_.Append(directory_entries_[current_directory_entry_
 715       ].filename);
 716 }
 717
 718 void FileEnumerator::GetFindInfo(FindInfo* info) {
 719   DCHECK(info);
 720
 721   if (current_directory_entry_ >= directory_entries_.size())
 722     return;
 723
 724   DirectoryEntryInfo* cur_entry = &directory_entries_[current_directory_entry_];
 725   memcpy(&(info->stat), &(cur_entry->stat), sizeof(info->stat));
 726   info->filename.assign(cur_entry->filename.value());
 727 }
 728
 729 bool FileEnumerator::IsDirectory(const FindInfo& info) {
 730   return S_ISDIR(info.stat.st_mode);
 731 }
 732
 733 // static
 734 FilePath FileEnumerator::GetFilename(const FindInfo& find_info) {
 735   return FilePath(find_info.filename);
 736 }
 737
 738 // static
 739 int64 FileEnumerator::GetFilesize(const FindInfo& find_info) {
 740   return find_info.stat.st_size;
 741 }
 742
 743 // static
 744 base::Time FileEnumerator::GetLastModifiedTime(const FindInfo& find_info) {
 745   return base::Time::FromTimeT(find_info.stat.st_mtime);
 746 }
 747
 748 bool FileEnumerator::ReadDirectory(std::vector<DirectoryEntryInfo>* entries,
 749                                    const FilePath& source, bool show_links) {
 750   base::ThreadRestrictions::AssertIOAllowed();
 751   DIR* dir = opendir(source.value().c_str());
 752   if (!dir)
 753     return false;
 754
 755 #if !defined(OS_LINUX) && !defined(OS_MACOSX) && !defined(OS_FREEBSD) && \
 756     !defined(OS_OPENBSD) && !defined(OS_SOLARIS) && !defined(OS_ANDROID)
 757   #error Port warning: depending on the definition of struct dirent, \
 758          additional space for pathname may be needed
 759 #endif
 760
 761   struct dirent dent_buf;
 762   struct dirent* dent;
 763   while (readdir_r(dir, &dent_buf, &dent) == 0 && dent) {
 764     DirectoryEntryInfo info;
 765     info.filename = FilePath(dent->d_name);
 766
 767     FilePath full_name = source.Append(dent->d_name);
 768     int ret;
 769     if (show_links)
 770       ret = lstat(full_name.value().c_str(), &info.stat);
 771     else
 772       ret = stat(full_name.value().c_str(), &info.stat);
 773     if (ret < 0) {
 774       // Print the stat() error message unless it was ENOENT and we're
 775       // following symlinks.
 776       if (!(errno == ENOENT && !show_links)) {
 777         PLOG(ERROR) << "Couldn't stat "
 778                     << source.Append(dent->d_name).value();
 779       }
 780       memset(&info.stat, 0, sizeof(info.stat));
 781     }
 782     entries->push_back(info);
 783   }
 784
 785   closedir(dir);
 786   return true;
 787 }
 788
 789 ///////////////////////////////////////////////
 790 // MemoryMappedFile
 791
 792 MemoryMappedFile::MemoryMappedFile()
 793     : file_(base::kInvalidPlatformFileValue),
 794       data_(NULL),
 795       length_(0) {
 796 }
 797
 798 bool MemoryMappedFile::MapFileToMemoryInternal() {
 799   base::ThreadRestrictions::AssertIOAllowed();
 800
 801   struct stat file_stat;
 802   if (fstat(file_, &file_stat) == base::kInvalidPlatformFileValue) {
 803     LOG(ERROR) << "Couldn't fstat " << file_ << ", errno " << errno;
 804     return false;
 805   }
 806   length_ = file_stat.st_size;
 807
 808   data_ = static_cast<uint8*>(
 809       mmap(NULL, length_, PROT_READ, MAP_SHARED, file_, 0));
 810   if (data_ == MAP_FAILED)
 811     LOG(ERROR) << "Couldn't mmap " << file_ << ", errno " << errno;
 812
 813   return data_ != MAP_FAILED;
 814 }
 815
 816 void MemoryMappedFile::CloseHandles() {
 817   base::ThreadRestrictions::AssertIOAllowed();
 818
 819   if (data_ != NULL)
 820     munmap(data_, length_);
 821   if (file_ != base::kInvalidPlatformFileValue)
 822     ignore_result(HANDLE_EINTR(close(file_)));
 823
 824   data_ = NULL;
 825   length_ = 0;
 826   file_ = base::kInvalidPlatformFileValue;
 827 }
 828
 829 bool HasFileBeenModifiedSince(const FileEnumerator::FindInfo& find_info,
 830                               const base::Time& cutoff_time) {
 831   return static_cast<time_t>(find_info.stat.st_mtime) >= cutoff_time.ToTimeT();
 832 }
 833
 834 bool NormalizeFilePath(const FilePath& path, FilePath* normalized_path) {
 835   FilePath real_path_result;
 836   if (!RealPath(path, &real_path_result))
 837     return false;
 838
 839   // To be consistant with windows, fail if |real_path_result| is a
 840   // directory.
 841   stat_wrapper_t file_info;
 842   if (CallStat(real_path_result.value().c_str(), &file_info) != 0 ||
 843       S_ISDIR(file_info.st_mode))
 844     return false;
 845
 846   *normalized_path = real_path_result;
 847   return true;
 848 }
 849
 850 #if !defined(OS_MACOSX)
 851 bool GetTempDir(FilePath* path) {
 852   const char* tmp = getenv("TMPDIR");
 853   if (tmp)
 854     *path = FilePath(tmp);
 855   else
 856 #if defined(OS_ANDROID)
 857     *path = FilePath("/data/local/tmp");
 858 #else
 859     *path = FilePath("/tmp");
 860 #endif
 861   return true;
 862 }
 863
 864 #if !defined(OS_ANDROID)
 865 bool GetShmemTempDir(FilePath* path) {
 866   *path = FilePath("/dev/shm");
 867   return true;
 868 }
 869 #endif
 870
 871 FilePath GetHomeDir() {
 872   const char* home_dir = getenv("HOME");
 873   if (home_dir && home_dir[0])
 874     return FilePath(home_dir);
 875
 876 #if defined(OS_ANDROID)
 877   LOG(WARNING) << "OS_ANDROID: Home directory lookup not yet implemented.";
 878 #else
 879   // g_get_home_dir calls getpwent, which can fall through to LDAP calls.
 880   base::ThreadRestrictions::AssertIOAllowed();
 881
 882   home_dir = g_get_home_dir();
 883   if (home_dir && home_dir[0])
 884     return FilePath(home_dir);
 885 #endif
 886
 887   FilePath rv;
 888   if (file_util::GetTempDir(&rv))
 889     return rv;
 890
 891   // Last resort.
 892   return FilePath("/tmp");
 893 }
 894
 895 bool CopyFile(const FilePath& from_path, const FilePath& to_path) {
 896   base::ThreadRestrictions::AssertIOAllowed();
 897   int infile = HANDLE_EINTR(open(from_path.value().c_str(), O_RDONLY));
 898   if (infile < 0)
 899     return false;
 900
 901   int outfile = HANDLE_EINTR(creat(to_path.value().c_str(), 0666));
 902   if (outfile < 0) {
 903     ignore_result(HANDLE_EINTR(close(infile)));
 904     return false;
 905   }
 906
 907   const size_t kBufferSize = 32768;
 908   std::vector<char> buffer(kBufferSize);
 909   bool result = true;
 910
 911   while (result) {
 912     ssize_t bytes_read = HANDLE_EINTR(read(infile, &buffer[0], buffer.size()));
 913     if (bytes_read < 0) {
 914       result = false;
 915       break;
 916     }
 917     if (bytes_read == 0)
 918       break;
 919     // Allow for partial writes
 920     ssize_t bytes_written_per_read = 0;
 921     do {
 922       ssize_t bytes_written_partial = HANDLE_EINTR(write(
 923           outfile,
 924           &buffer[bytes_written_per_read],
 925           bytes_read - bytes_written_per_read));
 926       if (bytes_written_partial < 0) {
 927         result = false;
 928         break;
 929       }
 930       bytes_written_per_read += bytes_written_partial;
 931     } while (bytes_written_per_read < bytes_read);
 932   }
 933
 934   if (HANDLE_EINTR(close(infile)) < 0)
 935     result = false;
 936   if (HANDLE_EINTR(close(outfile)) < 0)
 937     result = false;
 938
 939   return result;
 940 }
 941 #endif  // defined(OS_MACOSX)
 942
 943 }  // namespace file_util