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 #ifdef __ANDROID__
  31 #include "settings.h" // For g_settings
  32 #endif
  33
  34 namespace fs
  35 {
  36
  37 #ifdef _WIN32 // WINDOWS
  38
  39 #define _WIN32_WINNT 0x0501
  40 #include <windows.h>
  41 #include <shlwapi.h>
  42
  43 std::vector<DirListNode> GetDirListing(const std::string &pathstring)
  44 {
  45         std::vector<DirListNode> listing;
  46
  47         WIN32_FIND_DATA FindFileData;
  48         HANDLE hFind = INVALID_HANDLE_VALUE;
  49         DWORD dwError;
  50
  51         std::string dirSpec = pathstring + "\\*";
  52
  53         // Find the first file in the directory.
  54         hFind = FindFirstFile(dirSpec.c_str(), &FindFileData);
  55
  56         if (hFind == INVALID_HANDLE_VALUE) {
  57                 dwError = GetLastError();
  58                 if (dwError != ERROR_FILE_NOT_FOUND && dwError != ERROR_PATH_NOT_FOUND) {
  59                         errorstream << "GetDirListing: FindFirstFile error."
  60                                         << " Error is " << dwError << std::endl;
  61                 }
  62         } else {
  63                 // NOTE:
  64                 // Be very sure to not include '..' in the results, it will
  65                 // result in an epic failure when deleting stuff.
  66
  67                 DirListNode node;
  68                 node.name = FindFileData.cFileName;
  69                 node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
  70                 if (node.name != "." && node.name != "..")
  71                         listing.push_back(node);
  72
  73                 // List all the other files in the directory.
  74                 while (FindNextFile(hFind, &FindFileData) != 0) {
  75                         DirListNode node;
  76                         node.name = FindFileData.cFileName;
  77                         node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
  78                         if(node.name != "." && node.name != "..")
  79                                 listing.push_back(node);
  80                 }
  81
  82                 dwError = GetLastError();
  83                 FindClose(hFind);
  84                 if (dwError != ERROR_NO_MORE_FILES) {
  85                         errorstream << "GetDirListing: FindNextFile error."
  86                                         << " Error is " << dwError << std::endl;
  87                         listing.clear();
  88                         return listing;
  89                 }
  90         }
  91         return listing;
  92 }
  93
  94 bool CreateDir(const std::string &path)
  95 {
  96         bool r = CreateDirectory(path.c_str(), NULL);
  97         if(r == true)
  98                 return true;
  99         if(GetLastError() == ERROR_ALREADY_EXISTS)
 100                 return true;
 101         return false;
 102 }
 103
 104 bool PathExists(const std::string &path)
 105 {
 106         return (GetFileAttributes(path.c_str()) != INVALID_FILE_ATTRIBUTES);
 107 }
 108
 109 bool IsPathAbsolute(const std::string &path)
 110 {
 111         return !PathIsRelative(path.c_str());
 112 }
 113
 114 bool IsDir(const std::string &path)
 115 {
 116         DWORD attr = GetFileAttributes(path.c_str());
 117         return (attr != INVALID_FILE_ATTRIBUTES &&
 118                         (attr & FILE_ATTRIBUTE_DIRECTORY));
 119 }
 120
 121 bool IsDirDelimiter(char c)
 122 {
 123         return c == '/' || c == '\\';
 124 }
 125
 126 bool RecursiveDelete(const std::string &path)
 127 {
 128         infostream << "Recursively deleting \"" << path << "\"" << std::endl;
 129         if (!IsDir(path)) {
 130                 infostream << "RecursiveDelete: Deleting file  " << path << std::endl;
 131                 if (!DeleteFile(path.c_str())) {
 132                         errorstream << "RecursiveDelete: Failed to delete file "
 133                                         << path << std::endl;
 134                         return false;
 135                 }
 136                 return true;
 137         }
 138         infostream << "RecursiveDelete: Deleting content of directory "
 139                         << path << std::endl;
 140         std::vector<DirListNode> content = GetDirListing(path);
 141         for (const DirListNode &n: content) {
 142                 std::string fullpath = path + DIR_DELIM + n.name;
 143                 if (!RecursiveDelete(fullpath)) {
 144                         errorstream << "RecursiveDelete: Failed to recurse to "
 145                                         << fullpath << std::endl;
 146                         return false;
 147                 }
 148         }
 149         infostream << "RecursiveDelete: Deleting directory " << path << std::endl;
 150         if (!RemoveDirectory(path.c_str())) {
 151                 errorstream << "Failed to recursively delete directory "
 152                                 << path << std::endl;
 153                 return false;
 154         }
 155         return true;
 156 }
 157
 158 bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
 159 {
 160         DWORD attr = GetFileAttributes(path.c_str());
 161         bool is_directory = (attr != INVALID_FILE_ATTRIBUTES &&
 162                         (attr & FILE_ATTRIBUTE_DIRECTORY));
 163         if(!is_directory)
 164         {
 165                 bool did = DeleteFile(path.c_str());
 166                 return did;
 167         }
 168         else
 169         {
 170                 bool did = RemoveDirectory(path.c_str());
 171                 return did;
 172         }
 173 }
 174
 175 std::string TempPath()
 176 {
 177         DWORD bufsize = GetTempPath(0, NULL);
 178         if(bufsize == 0){
 179                 errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
 180                 return "";
 181         }
 182         std::vector<char> buf(bufsize);
 183         DWORD len = GetTempPath(bufsize, &buf[0]);
 184         if(len == 0 || len > bufsize){
 185                 errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
 186                 return "";
 187         }
 188         return std::string(buf.begin(), buf.begin() + len);
 189 }
 190
 191 #else // POSIX
 192
 193 #include <sys/types.h>
 194 #include <dirent.h>
 195 #include <sys/stat.h>
 196 #include <sys/wait.h>
 197 #include <unistd.h>
 198
 199 std::vector<DirListNode> GetDirListing(const std::string &pathstring)
 200 {
 201         std::vector<DirListNode> listing;
 202
 203         DIR *dp;
 204         struct dirent *dirp;
 205         if((dp = opendir(pathstring.c_str())) == NULL) {
 206                 //infostream<<"Error("<<errno<<") opening "<<pathstring<<std::endl;
 207                 return listing;
 208         }
 209
 210         while ((dirp = readdir(dp)) != NULL) {
 211                 // NOTE:
 212                 // Be very sure to not include '..' in the results, it will
 213                 // result in an epic failure when deleting stuff.
 214                 if(strcmp(dirp->d_name, ".") == 0 || strcmp(dirp->d_name, "..") == 0)
 215                         continue;
 216
 217                 DirListNode node;
 218                 node.name = dirp->d_name;
 219
 220                 int isdir = -1; // -1 means unknown
 221
 222                 /*
 223                         POSIX doesn't define d_type member of struct dirent and
 224                         certain filesystems on glibc/Linux will only return
 225                         DT_UNKNOWN for the d_type member.
 226
 227                         Also we don't know whether symlinks are directories or not.
 228                 */
 229 #ifdef _DIRENT_HAVE_D_TYPE
 230                 if(dirp->d_type != DT_UNKNOWN && dirp->d_type != DT_LNK)
 231                         isdir = (dirp->d_type == DT_DIR);
 232 #endif /* _DIRENT_HAVE_D_TYPE */
 233
 234                 /*
 235                         Was d_type DT_UNKNOWN, DT_LNK or nonexistent?
 236                         If so, try stat().
 237                 */
 238                 if(isdir == -1) {
 239                         struct stat statbuf{};
 240                         if (stat((pathstring + "/" + node.name).c_str(), &statbuf))
 241                                 continue;
 242                         isdir = ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
 243                 }
 244                 node.dir = isdir;
 245                 listing.push_back(node);
 246         }
 247         closedir(dp);
 248
 249         return listing;
 250 }
 251
 252 bool CreateDir(const std::string &path)
 253 {
 254         int r = mkdir(path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
 255         if (r == 0) {
 256                 return true;
 257         }
 258
 259         // If already exists, return true
 260         if (errno == EEXIST)
 261                 return true;
 262         return false;
 263
 264 }
 265
 266 bool PathExists(const std::string &path)
 267 {
 268         struct stat st{};
 269         return (stat(path.c_str(),&st) == 0);
 270 }
 271
 272 bool IsPathAbsolute(const std::string &path)
 273 {
 274         return path[0] == '/';
 275 }
 276
 277 bool IsDir(const std::string &path)
 278 {
 279         struct stat statbuf{};
 280         if(stat(path.c_str(), &statbuf))
 281                 return false; // Actually error; but certainly not a directory
 282         return ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
 283 }
 284
 285 bool IsDirDelimiter(char c)
 286 {
 287         return c == '/';
 288 }
 289
 290 bool RecursiveDelete(const std::string &path)
 291 {
 292         /*
 293                 Execute the 'rm' command directly, by fork() and execve()
 294         */
 295
 296         infostream<<"Removing \""<<path<<"\""<<std::endl;
 297
 298         pid_t child_pid = fork();
 299
 300         if(child_pid == 0)
 301         {
 302                 // Child
 303                 const char *argv[4] = {
 304 #ifdef __ANDROID__
 305                         "/system/bin/rm",
 306 #else
 307                         "/bin/rm",
 308 #endif
 309                         "-rf",
 310                         path.c_str(),
 311                         NULL
 312                 };
 313
 314                 verbosestream<<"Executing '"<<argv[0]<<"' '"<<argv[1]<<"' '"
 315                                 <<argv[2]<<"'"<<std::endl;
 316
 317                 execv(argv[0], const_cast<char**>(argv));
 318
 319                 // Execv shouldn't return. Failed.
 320                 _exit(1);
 321         }
 322         else
 323         {
 324                 // Parent
 325                 int child_status;
 326                 pid_t tpid;
 327                 do{
 328                         tpid = wait(&child_status);
 329                 }while(tpid != child_pid);
 330                 return (child_status == 0);
 331         }
 332 }
 333
 334 bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
 335 {
 336         if (IsDir(path)) {
 337                 bool did = (rmdir(path.c_str()) == 0);
 338                 if (!did)
 339                         errorstream << "rmdir errno: " << errno << ": " << strerror(errno)
 340                                         << std::endl;
 341                 return did;
 342         }
 343
 344         bool did = (unlink(path.c_str()) == 0);
 345         if (!did)
 346                 errorstream << "unlink errno: " << errno << ": " << strerror(errno)
 347                                 << std::endl;
 348         return did;
 349 }
 350
 351 std::string TempPath()
 352 {
 353         /*
 354                 Should the environment variables TMPDIR, TMP and TEMP
 355                 and the macro P_tmpdir (if defined by stdio.h) be checked
 356                 before falling back on /tmp?
 357
 358                 Probably not, because this function is intended to be
 359                 compatible with lua's os.tmpname which under the default
 360                 configuration hardcodes mkstemp("/tmp/lua_XXXXXX").
 361         */
 362 #ifdef __ANDROID__
 363         return g_settings->get("TMPFolder");
 364 #else
 365         return DIR_DELIM "tmp";
 366 #endif
 367 }
 368
 369 #endif
 370
 371 void GetRecursiveDirs(std::vector<std::string> &dirs, const std::string &dir)
 372 {
 373         static const std::set<char> chars_to_ignore = { '_', '.' };
 374         if (dir.empty() || !IsDir(dir))
 375                 return;
 376         dirs.push_back(dir);
 377         fs::GetRecursiveSubPaths(dir, dirs, false, chars_to_ignore);
 378 }
 379
 380 std::vector<std::string> GetRecursiveDirs(const std::string &dir)
 381 {
 382         std::vector<std::string> result;
 383         GetRecursiveDirs(result, dir);
 384         return result;
 385 }
 386
 387 void GetRecursiveSubPaths(const std::string &path,
 388                   std::vector<std::string> &dst,
 389                   bool list_files,
 390                   const std::set<char> &ignore)
 391 {
 392         std::vector<DirListNode> content = GetDirListing(path);
 393         for (const auto &n : content) {
 394                 std::string fullpath = path + DIR_DELIM + n.name;
 395                 if (ignore.count(n.name[0]))
 396                         continue;
 397                 if (list_files || n.dir)
 398                         dst.push_back(fullpath);
 399                 if (n.dir)
 400                         GetRecursiveSubPaths(fullpath, dst, list_files, ignore);
 401         }
 402 }
 403
 404 bool RecursiveDeleteContent(const std::string &path)
 405 {
 406         infostream<<"Removing content of \""<<path<<"\""<<std::endl;
 407         std::vector<DirListNode> list = GetDirListing(path);
 408         for (const DirListNode &dln : list) {
 409                 if(trim(dln.name) == "." || trim(dln.name) == "..")
 410                         continue;
 411                 std::string childpath = path + DIR_DELIM + dln.name;
 412                 bool r = RecursiveDelete(childpath);
 413                 if(!r) {
 414                         errorstream << "Removing \"" << childpath << "\" failed" << std::endl;
 415                         return false;
 416                 }
 417         }
 418         return true;
 419 }
 420
 421 bool CreateAllDirs(const std::string &path)
 422 {
 423
 424         std::vector<std::string> tocreate;
 425         std::string basepath = path;
 426         while(!PathExists(basepath))
 427         {
 428                 tocreate.push_back(basepath);
 429                 basepath = RemoveLastPathComponent(basepath);
 430                 if(basepath.empty())
 431                         break;
 432         }
 433         for(int i=tocreate.size()-1;i>=0;i--)
 434                 if(!CreateDir(tocreate[i]))
 435                         return false;
 436         return true;
 437 }
 438
 439 bool CopyFileContents(const std::string &source, const std::string &target)
 440 {
 441         FILE *sourcefile = fopen(source.c_str(), "rb");
 442         if(sourcefile == NULL){
 443                 errorstream<<source<<": can't open for reading: "
 444                         <<strerror(errno)<<std::endl;
 445                 return false;
 446         }
 447
 448         FILE *targetfile = fopen(target.c_str(), "wb");
 449         if(targetfile == NULL){
 450                 errorstream<<target<<": can't open for writing: "
 451                         <<strerror(errno)<<std::endl;
 452                 fclose(sourcefile);
 453                 return false;
 454         }
 455
 456         size_t total = 0;
 457         bool retval = true;
 458         bool done = false;
 459         char readbuffer[BUFSIZ];
 460         while(!done){
 461                 size_t readbytes = fread(readbuffer, 1,
 462                                 sizeof(readbuffer), sourcefile);
 463                 total += readbytes;
 464                 if(ferror(sourcefile)){
 465                         errorstream<<source<<": IO error: "
 466                                 <<strerror(errno)<<std::endl;
 467                         retval = false;
 468                         done = true;
 469                 }
 470                 if(readbytes > 0){
 471                         fwrite(readbuffer, 1, readbytes, targetfile);
 472                 }
 473                 if(feof(sourcefile) || ferror(sourcefile)){
 474                         // flush destination file to catch write errors
 475                         // (e.g. disk full)
 476                         fflush(targetfile);
 477                         done = true;
 478                 }
 479                 if(ferror(targetfile)){
 480                         errorstream<<target<<": IO error: "
 481                                         <<strerror(errno)<<std::endl;
 482                         retval = false;
 483                         done = true;
 484                 }
 485         }
 486         infostream<<"copied "<<total<<" bytes from "
 487                 <<source<<" to "<<target<<std::endl;
 488         fclose(sourcefile);
 489         fclose(targetfile);
 490         return retval;
 491 }
 492
 493 bool CopyDir(const std::string &source, const std::string &target)
 494 {
 495         if(PathExists(source)){
 496                 if(!PathExists(target)){
 497                         fs::CreateAllDirs(target);
 498                 }
 499                 bool retval = true;
 500                 std::vector<DirListNode> content = fs::GetDirListing(source);
 501
 502                 for (const auto &dln : content) {
 503                         std::string sourcechild = source + DIR_DELIM + dln.name;
 504                         std::string targetchild = target + DIR_DELIM + dln.name;
 505                         if(dln.dir){
 506                                 if(!fs::CopyDir(sourcechild, targetchild)){
 507                                         retval = false;
 508                                 }
 509                         }
 510                         else {
 511                                 if(!fs::CopyFileContents(sourcechild, targetchild)){
 512                                         retval = false;
 513                                 }
 514                         }
 515                 }
 516                 return retval;
 517         }
 518
 519         return false;
 520 }
 521
 522 bool PathStartsWith(const std::string &path, const std::string &prefix)
 523 {
 524         size_t pathsize = path.size();
 525         size_t pathpos = 0;
 526         size_t prefixsize = prefix.size();
 527         size_t prefixpos = 0;
 528         for(;;){
 529                 bool delim1 = pathpos == pathsize
 530                         || IsDirDelimiter(path[pathpos]);
 531                 bool delim2 = prefixpos == prefixsize
 532                         || IsDirDelimiter(prefix[prefixpos]);
 533
 534                 if(delim1 != delim2)
 535                         return false;
 536
 537                 if(delim1){
 538                         while(pathpos < pathsize &&
 539                                         IsDirDelimiter(path[pathpos]))
 540                                 ++pathpos;
 541                         while(prefixpos < prefixsize &&
 542                                         IsDirDelimiter(prefix[prefixpos]))
 543                                 ++prefixpos;
 544                         if(prefixpos == prefixsize)
 545                                 return true;
 546                         if(pathpos == pathsize)
 547                                 return false;
 548                 }
 549                 else{
 550                         size_t len = 0;
 551                         do{
 552                                 char pathchar = path[pathpos+len];
 553                                 char prefixchar = prefix[prefixpos+len];
 554                                 if(FILESYS_CASE_INSENSITIVE){
 555                                         pathchar = tolower(pathchar);
 556                                         prefixchar = tolower(prefixchar);
 557                                 }
 558                                 if(pathchar != prefixchar)
 559                                         return false;
 560                                 ++len;
 561                         } while(pathpos+len < pathsize
 562                                         && !IsDirDelimiter(path[pathpos+len])
 563                                         && prefixpos+len < prefixsize
 564                                         && !IsDirDelimiter(
 565                                                 prefix[prefixpos+len]));
 566                         pathpos += len;
 567                         prefixpos += len;
 568                 }
 569         }
 570 }
 571
 572 std::string RemoveLastPathComponent(const std::string &path,
 573                 std::string *removed, int count)
 574 {
 575         if(removed)
 576                 *removed = "";
 577
 578         size_t remaining = path.size();
 579
 580         for(int i = 0; i < count; ++i){
 581                 // strip a dir delimiter
 582                 while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
 583                         remaining--;
 584                 // strip a path component
 585                 size_t component_end = remaining;
 586                 while(remaining != 0 && !IsDirDelimiter(path[remaining-1]))
 587                         remaining--;
 588                 size_t component_start = remaining;
 589                 // strip a dir delimiter
 590                 while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
 591                         remaining--;
 592                 if(removed){
 593                         std::string component = path.substr(component_start,
 594                                         component_end - component_start);
 595                         if(i)
 596                                 *removed = component + DIR_DELIM + *removed;
 597                         else
 598                                 *removed = component;
 599                 }
 600         }
 601         return path.substr(0, remaining);
 602 }
 603
 604 std::string RemoveRelativePathComponents(std::string path)
 605 {
 606         size_t pos = path.size();
 607         size_t dotdot_count = 0;
 608         while (pos != 0) {
 609                 size_t component_with_delim_end = pos;
 610                 // skip a dir delimiter
 611                 while (pos != 0 && IsDirDelimiter(path[pos-1]))
 612                         pos--;
 613                 // strip a path component
 614                 size_t component_end = pos;
 615                 while (pos != 0 && !IsDirDelimiter(path[pos-1]))
 616                         pos--;
 617                 size_t component_start = pos;
 618
 619                 std::string component = path.substr(component_start,
 620                                 component_end - component_start);
 621                 bool remove_this_component = false;
 622                 if (component == ".") {
 623                         remove_this_component = true;
 624                 } else if (component == "..") {
 625                         remove_this_component = true;
 626                         dotdot_count += 1;
 627                 } else if (dotdot_count != 0) {
 628                         remove_this_component = true;
 629                         dotdot_count -= 1;
 630                 }
 631
 632                 if (remove_this_component) {
 633                         while (pos != 0 && IsDirDelimiter(path[pos-1]))
 634                                 pos--;
 635                         if (component_start == 0) {
 636                                 // We need to remove the delemiter too
 637                                 path = path.substr(component_with_delim_end, std::string::npos);
 638                         } else {
 639                                 path = path.substr(0, pos) + DIR_DELIM +
 640                                         path.substr(component_with_delim_end, std::string::npos);
 641                         }
 642                         if (pos > 0)
 643                                 pos++;
 644                 }
 645         }
 646
 647         if (dotdot_count > 0)
 648                 return "";
 649
 650         // remove trailing dir delimiters
 651         pos = path.size();
 652         while (pos != 0 && IsDirDelimiter(path[pos-1]))
 653                 pos--;
 654         return path.substr(0, pos);
 655 }
 656
 657 std::string AbsolutePath(const std::string &path)
 658 {
 659 #ifdef _WIN32
 660         char *abs_path = _fullpath(NULL, path.c_str(), MAX_PATH);
 661 #else
 662         char *abs_path = realpath(path.c_str(), NULL);
 663 #endif
 664         if (!abs_path) return "";
 665         std::string abs_path_str(abs_path);
 666         free(abs_path);
 667         return abs_path_str;
 668 }
 669
 670 const char *GetFilenameFromPath(const char *path)
 671 {
 672         const char *filename = strrchr(path, DIR_DELIM_CHAR);
 673         // Consistent with IsDirDelimiter this function handles '/' too
 674         if (DIR_DELIM_CHAR != '/') {
 675                 const char *tmp = strrchr(path, '/');
 676                 if (tmp && tmp > filename)
 677                         filename = tmp;
 678         }
 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 ReadFile(const std::string &path, std::string &out)
 733 {
 734         std::ifstream is(path, std::ios::binary | std::ios::ate);
 735         if (!is.good()) {
 736                 return false;
 737         }
 738
 739         auto size = is.tellg();
 740         out.resize(size);
 741         is.seekg(0);
 742         is.read(&out[0], size);
 743
 744         return true;
 745 }
 746
 747 bool Rename(const std::string &from, const std::string &to)
 748 {
 749         return rename(from.c_str(), to.c_str()) == 0;
 750 }
 751
 752 } // namespace fs
 753