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 <stdio.h>
  24 #include <string.h>
  25 #include <errno.h>
  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         {
 267                 return true;
 268         }
 269         else
 270         {
 271                 // If already exists, return true
 272                 if(errno == EEXIST)
 273                         return true;
 274                 return false;
 275         }
 276 }
 277
 278 bool PathExists(const std::string &path)
 279 {
 280         struct stat st;
 281         return (stat(path.c_str(),&st) == 0);
 282 }
 283
 284 bool IsPathAbsolute(const std::string &path)
 285 {
 286         return path[0] == '/';
 287 }
 288
 289 bool IsDir(const std::string &path)
 290 {
 291         struct stat statbuf;
 292         if(stat(path.c_str(), &statbuf))
 293                 return false; // Actually error; but certainly not a directory
 294         return ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
 295 }
 296
 297 bool IsDirDelimiter(char c)
 298 {
 299         return c == '/';
 300 }
 301
 302 bool RecursiveDelete(const std::string &path)
 303 {
 304         /*
 305                 Execute the 'rm' command directly, by fork() and execve()
 306         */
 307
 308         infostream<<"Removing \""<<path<<"\""<<std::endl;
 309
 310         //return false;
 311
 312         pid_t child_pid = fork();
 313
 314         if(child_pid == 0)
 315         {
 316                 // Child
 317                 char argv_data[3][10000];
 318                 strcpy(argv_data[0], "/bin/rm");
 319                 strcpy(argv_data[1], "-rf");
 320                 strncpy(argv_data[2], path.c_str(), 10000);
 321                 char *argv[4];
 322                 argv[0] = argv_data[0];
 323                 argv[1] = argv_data[1];
 324                 argv[2] = argv_data[2];
 325                 argv[3] = NULL;
 326
 327                 verbosestream<<"Executing '"<<argv[0]<<"' '"<<argv[1]<<"' '"
 328                                 <<argv[2]<<"'"<<std::endl;
 329
 330                 execv(argv[0], argv);
 331
 332                 // Execv shouldn't return. Failed.
 333                 _exit(1);
 334         }
 335         else
 336         {
 337                 // Parent
 338                 int child_status;
 339                 pid_t tpid;
 340                 do{
 341                         tpid = wait(&child_status);
 342                         //if(tpid != child_pid) process_terminated(tpid);
 343                 }while(tpid != child_pid);
 344                 return (child_status == 0);
 345         }
 346 }
 347
 348 bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
 349 {
 350         if(IsDir(path)){
 351                 bool did = (rmdir(path.c_str()) == 0);
 352                 if(!did)
 353                         errorstream<<"rmdir errno: "<<errno<<": "<<strerror(errno)
 354                                         <<std::endl;
 355                 return did;
 356         } else {
 357                 bool did = (unlink(path.c_str()) == 0);
 358                 if(!did)
 359                         errorstream<<"unlink errno: "<<errno<<": "<<strerror(errno)
 360                                         <<std::endl;
 361                 return did;
 362         }
 363 }
 364
 365 std::string TempPath()
 366 {
 367         /*
 368                 Should the environment variables TMPDIR, TMP and TEMP
 369                 and the macro P_tmpdir (if defined by stdio.h) be checked
 370                 before falling back on /tmp?
 371
 372                 Probably not, because this function is intended to be
 373                 compatible with lua's os.tmpname which under the default
 374                 configuration hardcodes mkstemp("/tmp/lua_XXXXXX").
 375         */
 376 #ifdef __ANDROID__
 377         return DIR_DELIM "sdcard" DIR_DELIM PROJECT_NAME DIR_DELIM "tmp";
 378 #else
 379         return DIR_DELIM "tmp";
 380 #endif
 381 }
 382
 383 #endif
 384
 385 void GetRecursiveSubPaths(const std::string &path, std::vector<std::string> &dst)
 386 {
 387         std::vector<DirListNode> content = GetDirListing(path);
 388         for(unsigned int  i=0; i<content.size(); i++){
 389                 const DirListNode &n = content[i];
 390                 std::string fullpath = path + DIR_DELIM + n.name;
 391                 dst.push_back(fullpath);
 392                 if (n.dir) {
 393                         GetRecursiveSubPaths(fullpath, dst);
 394                 }
 395         }
 396 }
 397
 398 bool DeletePaths(const std::vector<std::string> &paths)
 399 {
 400         bool success = true;
 401         // Go backwards to succesfully delete the output of GetRecursiveSubPaths
 402         for(int i=paths.size()-1; i>=0; i--){
 403                 const std::string &path = paths[i];
 404                 bool did = DeleteSingleFileOrEmptyDirectory(path);
 405                 if(!did){
 406                         errorstream<<"Failed to delete "<<path<<std::endl;
 407                         success = false;
 408                 }
 409         }
 410         return success;
 411 }
 412
 413 bool RecursiveDeleteContent(const std::string &path)
 414 {
 415         infostream<<"Removing content of \""<<path<<"\""<<std::endl;
 416         std::vector<DirListNode> list = GetDirListing(path);
 417         for(unsigned int i=0; i<list.size(); i++)
 418         {
 419                 if(trim(list[i].name) == "." || trim(list[i].name) == "..")
 420                         continue;
 421                 std::string childpath = path + DIR_DELIM + list[i].name;
 422                 bool r = RecursiveDelete(childpath);
 423                 if(r == false)
 424                 {
 425                         errorstream<<"Removing \""<<childpath<<"\" failed"<<std::endl;
 426                         return false;
 427                 }
 428         }
 429         return true;
 430 }
 431
 432 bool CreateAllDirs(const std::string &path)
 433 {
 434
 435         std::vector<std::string> tocreate;
 436         std::string basepath = path;
 437         while(!PathExists(basepath))
 438         {
 439                 tocreate.push_back(basepath);
 440                 basepath = RemoveLastPathComponent(basepath);
 441                 if(basepath.empty())
 442                         break;
 443         }
 444         for(int i=tocreate.size()-1;i>=0;i--)
 445                 if(!CreateDir(tocreate[i]))
 446                         return false;
 447         return true;
 448 }
 449
 450 bool CopyFileContents(const std::string &source, const std::string &target)
 451 {
 452         FILE *sourcefile = fopen(source.c_str(), "rb");
 453         if(sourcefile == NULL){
 454                 errorstream<<source<<": can't open for reading: "
 455                         <<strerror(errno)<<std::endl;
 456                 return false;
 457         }
 458
 459         FILE *targetfile = fopen(target.c_str(), "wb");
 460         if(targetfile == NULL){
 461                 errorstream<<target<<": can't open for writing: "
 462                         <<strerror(errno)<<std::endl;
 463                 fclose(sourcefile);
 464                 return false;
 465         }
 466
 467         size_t total = 0;
 468         bool retval = true;
 469         bool done = false;
 470         char readbuffer[BUFSIZ];
 471         while(!done){
 472                 size_t readbytes = fread(readbuffer, 1,
 473                                 sizeof(readbuffer), sourcefile);
 474                 total += readbytes;
 475                 if(ferror(sourcefile)){
 476                         errorstream<<source<<": IO error: "
 477                                 <<strerror(errno)<<std::endl;
 478                         retval = false;
 479                         done = true;
 480                 }
 481                 if(readbytes > 0){
 482                         fwrite(readbuffer, 1, readbytes, targetfile);
 483                 }
 484                 if(feof(sourcefile) || ferror(sourcefile)){
 485                         // flush destination file to catch write errors
 486                         // (e.g. disk full)
 487                         fflush(targetfile);
 488                         done = true;
 489                 }
 490                 if(ferror(targetfile)){
 491                         errorstream<<target<<": IO error: "
 492                                         <<strerror(errno)<<std::endl;
 493                         retval = false;
 494                         done = true;
 495                 }
 496         }
 497         infostream<<"copied "<<total<<" bytes from "
 498                 <<source<<" to "<<target<<std::endl;
 499         fclose(sourcefile);
 500         fclose(targetfile);
 501         return retval;
 502 }
 503
 504 bool CopyDir(const std::string &source, const std::string &target)
 505 {
 506         if(PathExists(source)){
 507                 if(!PathExists(target)){
 508                         fs::CreateAllDirs(target);
 509                 }
 510                 bool retval = true;
 511                 std::vector<DirListNode> content = fs::GetDirListing(source);
 512
 513                 for(unsigned int i=0; i < content.size(); i++){
 514                         std::string sourcechild = source + DIR_DELIM + content[i].name;
 515                         std::string targetchild = target + DIR_DELIM + content[i].name;
 516                         if(content[i].dir){
 517                                 if(!fs::CopyDir(sourcechild, targetchild)){
 518                                         retval = false;
 519                                 }
 520                         }
 521                         else {
 522                                 if(!fs::CopyFileContents(sourcechild, targetchild)){
 523                                         retval = false;
 524                                 }
 525                         }
 526                 }
 527                 return retval;
 528         }
 529         else {
 530                 return false;
 531         }
 532 }
 533
 534 bool PathStartsWith(const std::string &path, const std::string &prefix)
 535 {
 536         size_t pathsize = path.size();
 537         size_t pathpos = 0;
 538         size_t prefixsize = prefix.size();
 539         size_t prefixpos = 0;
 540         for(;;){
 541                 bool delim1 = pathpos == pathsize
 542                         || IsDirDelimiter(path[pathpos]);
 543                 bool delim2 = prefixpos == prefixsize
 544                         || IsDirDelimiter(prefix[prefixpos]);
 545
 546                 if(delim1 != delim2)
 547                         return false;
 548
 549                 if(delim1){
 550                         while(pathpos < pathsize &&
 551                                         IsDirDelimiter(path[pathpos]))
 552                                 ++pathpos;
 553                         while(prefixpos < prefixsize &&
 554                                         IsDirDelimiter(prefix[prefixpos]))
 555                                 ++prefixpos;
 556                         if(prefixpos == prefixsize)
 557                                 return true;
 558                         if(pathpos == pathsize)
 559                                 return false;
 560                 }
 561                 else{
 562                         size_t len = 0;
 563                         do{
 564                                 char pathchar = path[pathpos+len];
 565                                 char prefixchar = prefix[prefixpos+len];
 566                                 if(FILESYS_CASE_INSENSITIVE){
 567                                         pathchar = tolower(pathchar);
 568                                         prefixchar = tolower(prefixchar);
 569                                 }
 570                                 if(pathchar != prefixchar)
 571                                         return false;
 572                                 ++len;
 573                         } while(pathpos+len < pathsize
 574                                         && !IsDirDelimiter(path[pathpos+len])
 575                                         && prefixpos+len < prefixsize
 576                                         && !IsDirDelimiter(
 577                                                 prefix[prefixpos+len]));
 578                         pathpos += len;
 579                         prefixpos += len;
 580                 }
 581         }
 582 }
 583
 584 std::string RemoveLastPathComponent(const std::string &path,
 585                 std::string *removed, int count)
 586 {
 587         if(removed)
 588                 *removed = "";
 589
 590         size_t remaining = path.size();
 591
 592         for(int i = 0; i < count; ++i){
 593                 // strip a dir delimiter
 594                 while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
 595                         remaining--;
 596                 // strip a path component
 597                 size_t component_end = remaining;
 598                 while(remaining != 0 && !IsDirDelimiter(path[remaining-1]))
 599                         remaining--;
 600                 size_t component_start = remaining;
 601                 // strip a dir delimiter
 602                 while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
 603                         remaining--;
 604                 if(removed){
 605                         std::string component = path.substr(component_start,
 606                                         component_end - component_start);
 607                         if(i)
 608                                 *removed = component + DIR_DELIM + *removed;
 609                         else
 610                                 *removed = component;
 611                 }
 612         }
 613         return path.substr(0, remaining);
 614 }
 615
 616 std::string RemoveRelativePathComponents(std::string path)
 617 {
 618         size_t pos = path.size();
 619         size_t dotdot_count = 0;
 620         while(pos != 0){
 621                 size_t component_with_delim_end = pos;
 622                 // skip a dir delimiter
 623                 while(pos != 0 && IsDirDelimiter(path[pos-1]))
 624                         pos--;
 625                 // strip a path component
 626                 size_t component_end = pos;
 627                 while(pos != 0 && !IsDirDelimiter(path[pos-1]))
 628                         pos--;
 629                 size_t component_start = pos;
 630
 631                 std::string component = path.substr(component_start,
 632                                 component_end - component_start);
 633                 bool remove_this_component = false;
 634                 if(component == "." && component_start != 0){
 635                         remove_this_component = true;
 636                 }
 637                 else if(component == ".."){
 638                         remove_this_component = true;
 639                         dotdot_count += 1;
 640                 }
 641                 else if(dotdot_count != 0){
 642                         remove_this_component = true;
 643                         dotdot_count -= 1;
 644                 }
 645
 646                 if(remove_this_component){
 647                         while(pos != 0 && IsDirDelimiter(path[pos-1]))
 648                                 pos--;
 649                         path = path.substr(0, pos) + DIR_DELIM +
 650                                 path.substr(component_with_delim_end,
 651                                                 std::string::npos);
 652                         pos++;
 653                 }
 654         }
 655
 656         if(dotdot_count > 0)
 657                 return "";
 658
 659         // remove trailing dir delimiters
 660         pos = path.size();
 661         while(pos != 0 && IsDirDelimiter(path[pos-1]))
 662                 pos--;
 663         return path.substr(0, pos);
 664 }
 665
 666 std::string AbsolutePath(const std::string &path)
 667 {
 668 #ifdef _WIN32
 669         char *abs_path = _fullpath(NULL, path.c_str(), MAX_PATH);
 670 #else
 671         char *abs_path = realpath(path.c_str(), NULL);
 672 #endif
 673         if (!abs_path) return "";
 674         std::string abs_path_str(abs_path);
 675         free(abs_path);
 676         return abs_path_str;
 677 }
 678
 679 const char *GetFilenameFromPath(const char *path)
 680 {
 681         const char *filename = strrchr(path, DIR_DELIM_CHAR);
 682         return filename ? filename + 1 : path;
 683 }
 684
 685 bool safeWriteToFile(const std::string &path, const std::string &content)
 686 {
 687         std::string tmp_file = path + ".~mt";
 688
 689         // Write to a tmp file
 690         std::ofstream os(tmp_file.c_str(), std::ios::binary);
 691         if (!os.good())
 692                 return false;
 693         os << content;
 694         os.flush();
 695         os.close();
 696         if (os.fail()) {
 697                 // Remove the temporary file because writing it failed and it's useless.
 698                 remove(tmp_file.c_str());
 699                 return false;
 700         }
 701
 702         bool rename_success = false;
 703
 704         // Move the finished temporary file over the real file
 705 #ifdef _WIN32
 706         // When creating the file, it can cause Windows Search indexer, virus scanners and other apps
 707         // to query the file. This can make the move file call below fail.
 708         // We retry up to 5 times, with a 1ms sleep between, before we consider the whole operation failed
 709         int number_attempts = 0;
 710         while (number_attempts < 5) {
 711                 rename_success = MoveFileEx(tmp_file.c_str(), path.c_str(),
 712                                 MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH);
 713                 if (rename_success)
 714                         break;
 715                 sleep_ms(1);
 716                 ++number_attempts;
 717         }
 718 #else
 719         // On POSIX compliant systems rename() is specified to be able to swap the
 720         // file in place of the destination file, making this a truly error-proof
 721         // transaction.
 722         rename_success = rename(tmp_file.c_str(), path.c_str()) == 0;
 723 #endif
 724         if (!rename_success) {
 725                 warningstream << "Failed to write to file: " << path.c_str() << std::endl;
 726                 // Remove the temporary file because moving it over the target file
 727                 // failed.
 728                 remove(tmp_file.c_str());
 729                 return false;
 730         }
 731
 732         return true;
 733 }
 734
 735 bool Rename(const std::string &from, const std::string &to)
 736 {
 737         return rename(from.c_str(), to.c_str()) == 0;
 738 }
 739
 740 } // namespace fs
 741