src/filesys.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "filesys.h"
  21 #include "util/string.h"
  22 #include <iostream>
  23 #include <cstdio>
  24 #include <cstring>
  25 #include <cerrno>
  26 #include <fstream>
  27 #include "log.h"
  28 #include "config.h"
  29 #include "porting.h"
  30
  31 namespace fs
  32 {
  33
  34 #ifdef _WIN32 // WINDOWS
  35
  36 #define _WIN32_WINNT 0x0501
  37 #include <windows.h>
  38 #include <shlwapi.h>
  39
  40 std::vector<DirListNode> GetDirListing(const std::string &pathstring)
  41 {
  42         std::vector<DirListNode> listing;
  43
  44         WIN32_FIND_DATA FindFileData;
  45         HANDLE hFind = INVALID_HANDLE_VALUE;
  46         DWORD dwError;
  47
  48         std::string dirSpec = pathstring + "\\*";
  49
  50         // Find the first file in the directory.
  51         hFind = FindFirstFile(dirSpec.c_str(), &FindFileData);
  52
  53         if (hFind == INVALID_HANDLE_VALUE) {
  54                 dwError = GetLastError();
  55                 if (dwError != ERROR_FILE_NOT_FOUND && dwError != ERROR_PATH_NOT_FOUND) {
  56                         errorstream << "GetDirListing: FindFirstFile error."
  57                                         << " Error is " << dwError << std::endl;
  58                 }
  59         } else {
  60                 // NOTE:
  61                 // Be very sure to not include '..' in the results, it will
  62                 // result in an epic failure when deleting stuff.
  63
  64                 DirListNode node;
  65                 node.name = FindFileData.cFileName;
  66                 node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
  67                 if (node.name != "." && node.name != "..")
  68                         listing.push_back(node);
  69
  70                 // List all the other files in the directory.
  71                 while (FindNextFile(hFind, &FindFileData) != 0) {
  72                         DirListNode node;
  73                         node.name = FindFileData.cFileName;
  74                         node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
  75                         if(node.name != "." && node.name != "..")
  76                                 listing.push_back(node);
  77                 }
  78
  79                 dwError = GetLastError();
  80                 FindClose(hFind);
  81                 if (dwError != ERROR_NO_MORE_FILES) {
  82                         errorstream << "GetDirListing: FindNextFile error."
  83                                         << " Error is " << dwError << std::endl;
  84                         listing.clear();
  85                         return listing;
  86                 }
  87         }
  88         return listing;
  89 }
  90
  91 bool CreateDir(const std::string &path)
  92 {
  93         bool r = CreateDirectory(path.c_str(), NULL);
  94         if(r == true)
  95                 return true;
  96         if(GetLastError() == ERROR_ALREADY_EXISTS)
  97                 return true;
  98         return false;
  99 }
 100
 101 bool PathExists(const std::string &path)
 102 {
 103         return (GetFileAttributes(path.c_str()) != INVALID_FILE_ATTRIBUTES);
 104 }
 105
 106 bool IsPathAbsolute(const std::string &path)
 107 {
 108         return !PathIsRelative(path.c_str());
 109 }
 110
 111 bool IsDir(const std::string &path)
 112 {
 113         DWORD attr = GetFileAttributes(path.c_str());
 114         return (attr != INVALID_FILE_ATTRIBUTES &&
 115                         (attr & FILE_ATTRIBUTE_DIRECTORY));
 116 }
 117
 118 bool IsDirDelimiter(char c)
 119 {
 120         return c == '/' || c == '\\';
 121 }
 122
 123 bool RecursiveDelete(const std::string &path)
 124 {
 125         infostream<<"Recursively deleting \""<<path<<"\""<<std::endl;
 126
 127         DWORD attr = GetFileAttributes(path.c_str());
 128         bool is_directory = (attr != INVALID_FILE_ATTRIBUTES &&
 129                         (attr & FILE_ATTRIBUTE_DIRECTORY));
 130         if(!is_directory)
 131         {
 132                 infostream<<"RecursiveDelete: Deleting file "<<path<<std::endl;
 133                 //bool did = DeleteFile(path.c_str());
 134                 bool did = true;
 135                 if(!did){
 136                         errorstream<<"RecursiveDelete: Failed to delete file "
 137                                         <<path<<std::endl;
 138                         return false;
 139                 }
 140         }
 141         else
 142         {
 143                 infostream<<"RecursiveDelete: Deleting content of directory "
 144                                 <<path<<std::endl;
 145                 std::vector<DirListNode> content = GetDirListing(path);
 146                 for(size_t i=0; i<content.size(); i++){
 147                         const DirListNode &n = content[i];
 148                         std::string fullpath = path + DIR_DELIM + n.name;
 149                         bool did = RecursiveDelete(fullpath);
 150                         if(!did){
 151                                 errorstream<<"RecursiveDelete: Failed to recurse to "
 152                                                 <<fullpath<<std::endl;
 153                                 return false;
 154                         }
 155                 }
 156                 infostream<<"RecursiveDelete: Deleting directory "<<path<<std::endl;
 157                 //bool did = RemoveDirectory(path.c_str();
 158                 bool did = true;
 159                 if(!did){
 160                         errorstream<<"Failed to recursively delete directory "
 161                                         <<path<<std::endl;
 162                         return false;
 163                 }
 164         }
 165         return true;
 166 }
 167
 168 bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
 169 {
 170         DWORD attr = GetFileAttributes(path.c_str());
 171         bool is_directory = (attr != INVALID_FILE_ATTRIBUTES &&
 172                         (attr & FILE_ATTRIBUTE_DIRECTORY));
 173         if(!is_directory)
 174         {
 175                 bool did = DeleteFile(path.c_str());
 176                 return did;
 177         }
 178         else
 179         {
 180                 bool did = RemoveDirectory(path.c_str());
 181                 return did;
 182         }
 183 }
 184
 185 std::string TempPath()
 186 {
 187         DWORD bufsize = GetTempPath(0, NULL);
 188         if(bufsize == 0){
 189                 errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
 190                 return "";
 191         }
 192         std::vector<char> buf(bufsize);
 193         DWORD len = GetTempPath(bufsize, &buf[0]);
 194         if(len == 0 || len > bufsize){
 195                 errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
 196                 return "";
 197         }
 198         return std::string(buf.begin(), buf.begin() + len);
 199 }
 200
 201 #else // POSIX
 202
 203 #include <sys/types.h>
 204 #include <dirent.h>
 205 #include <sys/stat.h>
 206 #include <sys/wait.h>
 207 #include <unistd.h>
 208
 209 std::vector<DirListNode> GetDirListing(const std::string &pathstring)
 210 {
 211         std::vector<DirListNode> listing;
 212
 213         DIR *dp;
 214         struct dirent *dirp;
 215         if((dp = opendir(pathstring.c_str())) == NULL) {
 216                 //infostream<<"Error("<<errno<<") opening "<<pathstring<<std::endl;
 217                 return listing;
 218         }
 219
 220         while ((dirp = readdir(dp)) != NULL) {
 221                 // NOTE:
 222                 // Be very sure to not include '..' in the results, it will
 223                 // result in an epic failure when deleting stuff.
 224                 if(strcmp(dirp->d_name, ".") == 0 || strcmp(dirp->d_name, "..") == 0)
 225                         continue;
 226
 227                 DirListNode node;
 228                 node.name = dirp->d_name;
 229
 230                 int isdir = -1; // -1 means unknown
 231
 232                 /*
 233                         POSIX doesn't define d_type member of struct dirent and
 234                         certain filesystems on glibc/Linux will only return
 235                         DT_UNKNOWN for the d_type member.
 236
 237                         Also we don't know whether symlinks are directories or not.
 238                 */
 239 #ifdef _DIRENT_HAVE_D_TYPE
 240                 if(dirp->d_type != DT_UNKNOWN && dirp->d_type != DT_LNK)
 241                         isdir = (dirp->d_type == DT_DIR);
 242 #endif /* _DIRENT_HAVE_D_TYPE */
 243
 244                 /*
 245                         Was d_type DT_UNKNOWN, DT_LNK or nonexistent?
 246                         If so, try stat().
 247                 */
 248                 if(isdir == -1) {
 249                         struct stat statbuf{};
 250                         if (stat((pathstring + "/" + node.name).c_str(), &statbuf))
 251                                 continue;
 252                         isdir = ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
 253                 }
 254                 node.dir = isdir;
 255                 listing.push_back(node);
 256         }
 257         closedir(dp);
 258
 259         return listing;
 260 }
 261
 262 bool CreateDir(const std::string &path)
 263 {
 264         int r = mkdir(path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
 265         if (r == 0) {
 266                 return true;
 267         }
 268
 269         // If already exists, return true
 270         if (errno == EEXIST)
 271                 return true;
 272         return false;
 273
 274 }
 275
 276 bool PathExists(const std::string &path)
 277 {
 278         struct stat st{};
 279         return (stat(path.c_str(),&st) == 0);
 280 }
 281
 282 bool IsPathAbsolute(const std::string &path)
 283 {
 284         return path[0] == '/';
 285 }
 286
 287 bool IsDir(const std::string &path)
 288 {
 289         struct stat statbuf{};
 290         if(stat(path.c_str(), &statbuf))
 291                 return false; // Actually error; but certainly not a directory
 292         return ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
 293 }
 294
 295 bool IsDirDelimiter(char c)
 296 {
 297         return c == '/';
 298 }
 299
 300 bool RecursiveDelete(const std::string &path)
 301 {
 302         /*
 303                 Execute the 'rm' command directly, by fork() and execve()
 304         */
 305
 306         infostream<<"Removing \""<<path<<"\""<<std::endl;
 307
 308         //return false;
 309
 310         pid_t child_pid = fork();
 311
 312         if(child_pid == 0)
 313         {
 314                 // Child
 315                 char argv_data[3][10000];
 316                 strcpy(argv_data[0], "/bin/rm");
 317                 strcpy(argv_data[1], "-rf");
 318                 strncpy(argv_data[2], path.c_str(), 10000);
 319                 char *argv[4];
 320                 argv[0] = argv_data[0];
 321                 argv[1] = argv_data[1];
 322                 argv[2] = argv_data[2];
 323                 argv[3] = NULL;
 324
 325                 verbosestream<<"Executing '"<<argv[0]<<"' '"<<argv[1]<<"' '"
 326                                 <<argv[2]<<"'"<<std::endl;
 327
 328                 execv(argv[0], argv);
 329
 330                 // Execv shouldn't return. Failed.
 331                 _exit(1);
 332         }
 333         else
 334         {
 335                 // Parent
 336                 int child_status;
 337                 pid_t tpid;
 338                 do{
 339                         tpid = wait(&child_status);
 340                         //if(tpid != child_pid) process_terminated(tpid);
 341                 }while(tpid != child_pid);
 342                 return (child_status == 0);
 343         }
 344 }
 345
 346 bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
 347 {
 348         if (IsDir(path)) {
 349                 bool did = (rmdir(path.c_str()) == 0);
 350                 if (!did)
 351                         errorstream << "rmdir errno: " << errno << ": " << strerror(errno)
 352                                         << std::endl;
 353                 return did;
 354         }
 355
 356         bool did = (unlink(path.c_str()) == 0);
 357         if (!did)
 358                 errorstream << "unlink errno: " << errno << ": " << strerror(errno)
 359                                 << std::endl;
 360         return did;
 361 }
 362
 363 std::string TempPath()
 364 {
 365         /*
 366                 Should the environment variables TMPDIR, TMP and TEMP
 367                 and the macro P_tmpdir (if defined by stdio.h) be checked
 368                 before falling back on /tmp?
 369
 370                 Probably not, because this function is intended to be
 371                 compatible with lua's os.tmpname which under the default
 372                 configuration hardcodes mkstemp("/tmp/lua_XXXXXX").
 373         */
 374 #ifdef __ANDROID__
 375         return DIR_DELIM "sdcard" DIR_DELIM PROJECT_NAME DIR_DELIM "tmp";
 376 #else
 377         return DIR_DELIM "tmp";
 378 #endif
 379 }
 380
 381 #endif
 382
 383 void GetRecursiveSubPaths(const std::string &path, std::vector<std::string> &dst)
 384 {
 385         std::vector<DirListNode> content = GetDirListing(path);
 386         for (const auto &n : content) {
 387                 std::string fullpath = path + DIR_DELIM + n.name;
 388                 dst.push_back(fullpath);
 389                 if (n.dir) {
 390                         GetRecursiveSubPaths(fullpath, dst);
 391                 }
 392         }
 393 }
 394
 395 bool DeletePaths(const std::vector<std::string> &paths)
 396 {
 397         bool success = true;
 398         // Go backwards to succesfully delete the output of GetRecursiveSubPaths
 399         for(int i=paths.size()-1; i>=0; i--){
 400                 const std::string &path = paths[i];
 401                 bool did = DeleteSingleFileOrEmptyDirectory(path);
 402                 if(!did){
 403                         errorstream<<"Failed to delete "<<path<<std::endl;
 404                         success = false;
 405                 }
 406         }
 407         return success;
 408 }
 409
 410 bool RecursiveDeleteContent(const std::string &path)
 411 {
 412         infostream<<"Removing content of \""<<path<<"\""<<std::endl;
 413         std::vector<DirListNode> list = GetDirListing(path);
 414         for (const DirListNode &dln : list) {
 415                 if(trim(dln.name) == "." || trim(dln.name) == "..")
 416                         continue;
 417                 std::string childpath = path + DIR_DELIM + dln.name;
 418                 bool r = RecursiveDelete(childpath);
 419                 if(!r) {
 420                         errorstream << "Removing \"" << childpath << "\" failed" << std::endl;
 421                         return false;
 422                 }
 423         }
 424         return true;
 425 }
 426
 427 bool CreateAllDirs(const std::string &path)
 428 {
 429
 430         std::vector<std::string> tocreate;
 431         std::string basepath = path;
 432         while(!PathExists(basepath))
 433         {
 434                 tocreate.push_back(basepath);
 435                 basepath = RemoveLastPathComponent(basepath);
 436                 if(basepath.empty())
 437                         break;
 438         }
 439         for(int i=tocreate.size()-1;i>=0;i--)
 440                 if(!CreateDir(tocreate[i]))
 441                         return false;
 442         return true;
 443 }
 444
 445 bool CopyFileContents(const std::string &source, const std::string &target)
 446 {
 447         FILE *sourcefile = fopen(source.c_str(), "rb");
 448         if(sourcefile == NULL){
 449                 errorstream<<source<<": can't open for reading: "
 450                         <<strerror(errno)<<std::endl;
 451                 return false;
 452         }
 453
 454         FILE *targetfile = fopen(target.c_str(), "wb");
 455         if(targetfile == NULL){
 456                 errorstream<<target<<": can't open for writing: "
 457                         <<strerror(errno)<<std::endl;
 458                 fclose(sourcefile);
 459                 return false;
 460         }
 461
 462         size_t total = 0;
 463         bool retval = true;
 464         bool done = false;
 465         char readbuffer[BUFSIZ];
 466         while(!done){
 467                 size_t readbytes = fread(readbuffer, 1,
 468                                 sizeof(readbuffer), sourcefile);
 469                 total += readbytes;
 470                 if(ferror(sourcefile)){
 471                         errorstream<<source<<": IO error: "
 472                                 <<strerror(errno)<<std::endl;
 473                         retval = false;
 474                         done = true;
 475                 }
 476                 if(readbytes > 0){
 477                         fwrite(readbuffer, 1, readbytes, targetfile);
 478                 }
 479                 if(feof(sourcefile) || ferror(sourcefile)){
 480                         // flush destination file to catch write errors
 481                         // (e.g. disk full)
 482                         fflush(targetfile);
 483                         done = true;
 484                 }
 485                 if(ferror(targetfile)){
 486                         errorstream<<target<<": IO error: "
 487                                         <<strerror(errno)<<std::endl;
 488                         retval = false;
 489                         done = true;
 490                 }
 491         }
 492         infostream<<"copied "<<total<<" bytes from "
 493                 <<source<<" to "<<target<<std::endl;
 494         fclose(sourcefile);
 495         fclose(targetfile);
 496         return retval;
 497 }
 498
 499 bool CopyDir(const std::string &source, const std::string &target)
 500 {
 501         if(PathExists(source)){
 502                 if(!PathExists(target)){
 503                         fs::CreateAllDirs(target);
 504                 }
 505                 bool retval = true;
 506                 std::vector<DirListNode> content = fs::GetDirListing(source);
 507
 508                 for (const auto &dln : content) {
 509                         std::string sourcechild = source + DIR_DELIM + dln.name;
 510                         std::string targetchild = target + DIR_DELIM + dln.name;
 511                         if(dln.dir){
 512                                 if(!fs::CopyDir(sourcechild, targetchild)){
 513                                         retval = false;
 514                                 }
 515                         }
 516                         else {
 517                                 if(!fs::CopyFileContents(sourcechild, targetchild)){
 518                                         retval = false;
 519                                 }
 520                         }
 521                 }
 522                 return retval;
 523         }
 524
 525         return false;
 526 }
 527
 528 bool PathStartsWith(const std::string &path, const std::string &prefix)
 529 {
 530         size_t pathsize = path.size();
 531         size_t pathpos = 0;
 532         size_t prefixsize = prefix.size();
 533         size_t prefixpos = 0;
 534         for(;;){
 535                 bool delim1 = pathpos == pathsize
 536                         || IsDirDelimiter(path[pathpos]);
 537                 bool delim2 = prefixpos == prefixsize
 538                         || IsDirDelimiter(prefix[prefixpos]);
 539
 540                 if(delim1 != delim2)
 541                         return false;
 542
 543                 if(delim1){
 544                         while(pathpos < pathsize &&
 545                                         IsDirDelimiter(path[pathpos]))
 546                                 ++pathpos;
 547                         while(prefixpos < prefixsize &&
 548                                         IsDirDelimiter(prefix[prefixpos]))
 549                                 ++prefixpos;
 550                         if(prefixpos == prefixsize)
 551                                 return true;
 552                         if(pathpos == pathsize)
 553                                 return false;
 554                 }
 555                 else{
 556                         size_t len = 0;
 557                         do{
 558                                 char pathchar = path[pathpos+len];
 559                                 char prefixchar = prefix[prefixpos+len];
 560                                 if(FILESYS_CASE_INSENSITIVE){
 561                                         pathchar = tolower(pathchar);
 562                                         prefixchar = tolower(prefixchar);
 563                                 }
 564                                 if(pathchar != prefixchar)
 565                                         return false;
 566                                 ++len;
 567                         } while(pathpos+len < pathsize
 568                                         && !IsDirDelimiter(path[pathpos+len])
 569                                         && prefixpos+len < prefixsize
 570                                         && !IsDirDelimiter(
 571                                                 prefix[prefixpos+len]));
 572                         pathpos += len;
 573                         prefixpos += len;
 574                 }
 575         }
 576 }
 577
 578 std::string RemoveLastPathComponent(const std::string &path,
 579                 std::string *removed, int count)
 580 {
 581         if(removed)
 582                 *removed = "";
 583
 584         size_t remaining = path.size();
 585
 586         for(int i = 0; i < count; ++i){
 587                 // strip a dir delimiter
 588                 while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
 589                         remaining--;
 590                 // strip a path component
 591                 size_t component_end = remaining;
 592                 while(remaining != 0 && !IsDirDelimiter(path[remaining-1]))
 593                         remaining--;
 594                 size_t component_start = remaining;
 595                 // strip a dir delimiter
 596                 while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
 597                         remaining--;
 598                 if(removed){
 599                         std::string component = path.substr(component_start,
 600                                         component_end - component_start);
 601                         if(i)
 602                                 *removed = component + DIR_DELIM + *removed;
 603                         else
 604                                 *removed = component;
 605                 }
 606         }
 607         return path.substr(0, remaining);
 608 }
 609
 610 std::string RemoveRelativePathComponents(std::string path)
 611 {
 612         size_t pos = path.size();
 613         size_t dotdot_count = 0;
 614         while (pos != 0) {
 615                 size_t component_with_delim_end = pos;
 616                 // skip a dir delimiter
 617                 while (pos != 0 && IsDirDelimiter(path[pos-1]))
 618                         pos--;
 619                 // strip a path component
 620                 size_t component_end = pos;
 621                 while (pos != 0 && !IsDirDelimiter(path[pos-1]))
 622                         pos--;
 623                 size_t component_start = pos;
 624
 625                 std::string component = path.substr(component_start,
 626                                 component_end - component_start);
 627                 bool remove_this_component = false;
 628                 if (component == ".") {
 629                         remove_this_component = true;
 630                 } else if (component == "..") {
 631                         remove_this_component = true;
 632                         dotdot_count += 1;
 633                 } else if (dotdot_count != 0) {
 634                         remove_this_component = true;
 635                         dotdot_count -= 1;
 636                 }
 637
 638                 if (remove_this_component) {
 639                         while (pos != 0 && IsDirDelimiter(path[pos-1]))
 640                                 pos--;
 641                         if (component_start == 0) {
 642                                 // We need to remove the delemiter too
 643                                 path = path.substr(component_with_delim_end, std::string::npos);
 644                         } else {
 645                                 path = path.substr(0, pos) + DIR_DELIM +
 646                                         path.substr(component_with_delim_end, std::string::npos);
 647                         }
 648                         if (pos > 0)
 649                                 pos++;
 650                 }
 651         }
 652
 653         if (dotdot_count > 0)
 654                 return "";
 655
 656         // remove trailing dir delimiters
 657         pos = path.size();
 658         while (pos != 0 && IsDirDelimiter(path[pos-1]))
 659                 pos--;
 660         return path.substr(0, pos);
 661 }
 662
 663 std::string AbsolutePath(const std::string &path)
 664 {
 665 #ifdef _WIN32
 666         char *abs_path = _fullpath(NULL, path.c_str(), MAX_PATH);
 667 #else
 668         char *abs_path = realpath(path.c_str(), NULL);
 669 #endif
 670         if (!abs_path) return "";
 671         std::string abs_path_str(abs_path);
 672         free(abs_path);
 673         return abs_path_str;
 674 }
 675
 676 const char *GetFilenameFromPath(const char *path)
 677 {
 678         const char *filename = strrchr(path, DIR_DELIM_CHAR);
 679         return filename ? filename + 1 : path;
 680 }
 681
 682 bool safeWriteToFile(const std::string &path, const std::string &content)
 683 {
 684         std::string tmp_file = path + ".~mt";
 685
 686         // Write to a tmp file
 687         std::ofstream os(tmp_file.c_str(), std::ios::binary);
 688         if (!os.good())
 689                 return false;
 690         os << content;
 691         os.flush();
 692         os.close();
 693         if (os.fail()) {
 694                 // Remove the temporary file because writing it failed and it's useless.
 695                 remove(tmp_file.c_str());
 696                 return false;
 697         }
 698
 699         bool rename_success = false;
 700
 701         // Move the finished temporary file over the real file
 702 #ifdef _WIN32
 703         // When creating the file, it can cause Windows Search indexer, virus scanners and other apps
 704         // to query the file. This can make the move file call below fail.
 705         // We retry up to 5 times, with a 1ms sleep between, before we consider the whole operation failed
 706         int number_attempts = 0;
 707         while (number_attempts < 5) {
 708                 rename_success = MoveFileEx(tmp_file.c_str(), path.c_str(),
 709                                 MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH);
 710                 if (rename_success)
 711                         break;
 712                 sleep_ms(1);
 713                 ++number_attempts;
 714         }
 715 #else
 716         // On POSIX compliant systems rename() is specified to be able to swap the
 717         // file in place of the destination file, making this a truly error-proof
 718         // transaction.
 719         rename_success = rename(tmp_file.c_str(), path.c_str()) == 0;
 720 #endif
 721         if (!rename_success) {
 722                 warningstream << "Failed to write to file: " << path.c_str() << std::endl;
 723                 // Remove the temporary file because moving it over the target file
 724                 // failed.
 725                 remove(tmp_file.c_str());
 726                 return false;
 727         }
 728
 729         return true;
 730 }
 731
 732 bool Rename(const std::string &from, const std::string &to)
 733 {
 734         return rename(from.c_str(), to.c_str()) == 0;
 735 }
 736
 737 } // namespace fs
 738