src/porting.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 /*
  21         Random portability stuff
  22
  23         See comments in porting.h
  24 */
  25
  26 #include "porting.h"
  27
  28 #if defined(__FreeBSD__)  || defined(__NetBSD__) || defined(__DragonFly__) || defined(__OpenBSD__)
  29         #include <sys/types.h>
  30         #include <sys/sysctl.h>
  31         extern char **environ;
  32 #elif defined(_WIN32)
  33         #include <windows.h>
  34         #include <wincrypt.h>
  35         #include <algorithm>
  36         #include <shlwapi.h>
  37         #include <shellapi.h>
  38 #endif
  39 #if !defined(_WIN32)
  40         #include <unistd.h>
  41         #include <sys/utsname.h>
  42         #if !defined(__ANDROID__)
  43                 #include <spawn.h>
  44         #endif
  45 #endif
  46 #if defined(__hpux)
  47         #define _PSTAT64
  48         #include <sys/pstat.h>
  49 #endif
  50 #if defined(__ANDROID__)
  51         #include "porting_android.h"
  52 #endif
  53 #if defined(__APPLE__)
  54         // For _NSGetEnviron()
  55         // Related: https://gitlab.haskell.org/ghc/ghc/issues/2458
  56         #include <crt_externs.h>
  57 #endif
  58
  59 #if defined(__HAIKU__)
  60         #include <FindDirectory.h>
  61 #endif
  62
  63 #include "config.h"
  64 #include "debug.h"
  65 #include "filesys.h"
  66 #include "log.h"
  67 #include "util/string.h"
  68 #include <list>
  69 #include <cstdarg>
  70 #include <cstdio>
  71
  72 namespace porting
  73 {
  74
  75 /*
  76         Signal handler (grabs Ctrl-C on POSIX systems)
  77 */
  78
  79 bool g_killed = false;
  80
  81 bool *signal_handler_killstatus()
  82 {
  83         return &g_killed;
  84 }
  85
  86 #if !defined(_WIN32) // POSIX
  87         #include <signal.h>
  88
  89 void signal_handler(int sig)
  90 {
  91         if (!g_killed) {
  92                 if (sig == SIGINT) {
  93                         dstream << "INFO: signal_handler(): "
  94                                 << "Ctrl-C pressed, shutting down." << std::endl;
  95                 } else if (sig == SIGTERM) {
  96                         dstream << "INFO: signal_handler(): "
  97                                 << "got SIGTERM, shutting down." << std::endl;
  98                 }
  99
 100                 // Comment out for less clutter when testing scripts
 101                 /*dstream << "INFO: sigint_handler(): "
 102                                 << "Printing debug stacks" << std::endl;
 103                 debug_stacks_print();*/
 104
 105                 g_killed = true;
 106         } else {
 107                 (void)signal(sig, SIG_DFL);
 108         }
 109 }
 110
 111 void signal_handler_init(void)
 112 {
 113         (void)signal(SIGINT, signal_handler);
 114         (void)signal(SIGTERM, signal_handler);
 115 }
 116
 117 #else // _WIN32
 118         #include <signal.h>
 119
 120 BOOL WINAPI event_handler(DWORD sig)
 121 {
 122         switch (sig) {
 123         case CTRL_C_EVENT:
 124         case CTRL_CLOSE_EVENT:
 125         case CTRL_LOGOFF_EVENT:
 126         case CTRL_SHUTDOWN_EVENT:
 127                 if (!g_killed) {
 128                         dstream << "INFO: event_handler(): "
 129                                 << "Ctrl+C, Close Event, Logoff Event or Shutdown Event,"
 130                                 " shutting down." << std::endl;
 131                         g_killed = true;
 132                 } else {
 133                         (void)signal(SIGINT, SIG_DFL);
 134                 }
 135                 break;
 136         case CTRL_BREAK_EVENT:
 137                 break;
 138         }
 139
 140         return TRUE;
 141 }
 142
 143 void signal_handler_init(void)
 144 {
 145         SetConsoleCtrlHandler((PHANDLER_ROUTINE)event_handler, TRUE);
 146 }
 147
 148 #endif
 149
 150
 151 /*
 152         Path mangler
 153 */
 154
 155 // Default to RUN_IN_PLACE style relative paths
 156 std::string path_share = "..";
 157 std::string path_user = "..";
 158 std::string path_locale = path_share + DIR_DELIM + "locale";
 159 std::string path_cache = path_user + DIR_DELIM + "cache";
 160
 161
 162 std::string getDataPath(const char *subpath)
 163 {
 164         return path_share + DIR_DELIM + subpath;
 165 }
 166
 167 void pathRemoveFile(char *path, char delim)
 168 {
 169         // Remove filename and path delimiter
 170         int i;
 171         for(i = strlen(path)-1; i>=0; i--)
 172         {
 173                 if(path[i] == delim)
 174                         break;
 175         }
 176         path[i] = 0;
 177 }
 178
 179 bool detectMSVCBuildDir(const std::string &path)
 180 {
 181         const char *ends[] = {
 182                 "bin\\Release",
 183                 "bin\\MinSizeRel",
 184                 "bin\\RelWithDebInfo",
 185                 "bin\\Debug",
 186                 "bin\\Build",
 187                 NULL
 188         };
 189         return (!removeStringEnd(path, ends).empty());
 190 }
 191
 192 std::string get_sysinfo()
 193 {
 194 #ifdef _WIN32
 195
 196         std::ostringstream oss;
 197         LPSTR filePath = new char[MAX_PATH];
 198         UINT blockSize;
 199         VS_FIXEDFILEINFO *fixedFileInfo;
 200
 201         GetSystemDirectoryA(filePath, MAX_PATH);
 202         PathAppendA(filePath, "kernel32.dll");
 203
 204         DWORD dwVersionSize = GetFileVersionInfoSizeA(filePath, NULL);
 205         LPBYTE lpVersionInfo = new BYTE[dwVersionSize];
 206
 207         GetFileVersionInfoA(filePath, 0, dwVersionSize, lpVersionInfo);
 208         VerQueryValueA(lpVersionInfo, "\\", (LPVOID *)&fixedFileInfo, &blockSize);
 209
 210         oss << "Windows/"
 211                 << HIWORD(fixedFileInfo->dwProductVersionMS) << '.' // Major
 212                 << LOWORD(fixedFileInfo->dwProductVersionMS) << '.' // Minor
 213                 << HIWORD(fixedFileInfo->dwProductVersionLS) << ' '; // Build
 214
 215         #ifdef _WIN64
 216         oss << "x86_64";
 217         #else
 218         BOOL is64 = FALSE;
 219         if (IsWow64Process(GetCurrentProcess(), &is64) && is64)
 220                 oss << "x86_64"; // 32-bit app on 64-bit OS
 221         else
 222                 oss << "x86";
 223         #endif
 224
 225         delete[] lpVersionInfo;
 226         delete[] filePath;
 227
 228         return oss.str();
 229 #else
 230         struct utsname osinfo;
 231         uname(&osinfo);
 232         return std::string(osinfo.sysname) + "/"
 233                 + osinfo.release + " " + osinfo.machine;
 234 #endif
 235 }
 236
 237
 238 bool getCurrentWorkingDir(char *buf, size_t len)
 239 {
 240 #ifdef _WIN32
 241         DWORD ret = GetCurrentDirectory(len, buf);
 242         return (ret != 0) && (ret <= len);
 243 #else
 244         return getcwd(buf, len);
 245 #endif
 246 }
 247
 248
 249 bool getExecPathFromProcfs(char *buf, size_t buflen)
 250 {
 251 #ifndef _WIN32
 252         buflen--;
 253
 254         ssize_t len;
 255         if ((len = readlink("/proc/self/exe",     buf, buflen)) == -1 &&
 256                 (len = readlink("/proc/curproc/file", buf, buflen)) == -1 &&
 257                 (len = readlink("/proc/curproc/exe",  buf, buflen)) == -1)
 258                 return false;
 259
 260         buf[len] = '\0';
 261         return true;
 262 #else
 263         return false;
 264 #endif
 265 }
 266
 267 //// Windows
 268 #if defined(_WIN32)
 269
 270 bool getCurrentExecPath(char *buf, size_t len)
 271 {
 272         DWORD written = GetModuleFileNameA(NULL, buf, len);
 273         if (written == 0 || written == len)
 274                 return false;
 275
 276         return true;
 277 }
 278
 279
 280 //// Linux
 281 #elif defined(__linux__)
 282
 283 bool getCurrentExecPath(char *buf, size_t len)
 284 {
 285         if (!getExecPathFromProcfs(buf, len))
 286                 return false;
 287
 288         return true;
 289 }
 290
 291
 292 //// Mac OS X, Darwin
 293 #elif defined(__APPLE__)
 294
 295 bool getCurrentExecPath(char *buf, size_t len)
 296 {
 297         uint32_t lenb = (uint32_t)len;
 298         if (_NSGetExecutablePath(buf, &lenb) == -1)
 299                 return false;
 300
 301         return true;
 302 }
 303
 304
 305 //// FreeBSD, NetBSD, DragonFlyBSD
 306 #elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__DragonFly__)
 307
 308 bool getCurrentExecPath(char *buf, size_t len)
 309 {
 310         // Try getting path from procfs first, since valgrind
 311         // doesn't work with the latter
 312         if (getExecPathFromProcfs(buf, len))
 313                 return true;
 314
 315         int mib[4];
 316
 317         mib[0] = CTL_KERN;
 318         mib[1] = KERN_PROC;
 319         mib[2] = KERN_PROC_PATHNAME;
 320         mib[3] = -1;
 321
 322         if (sysctl(mib, 4, buf, &len, NULL, 0) == -1)
 323                 return false;
 324
 325         return true;
 326 }
 327
 328 #elif defined(__HAIKU__)
 329
 330 bool getCurrentExecPath(char *buf, size_t len)
 331 {
 332         return find_path(B_APP_IMAGE_SYMBOL, B_FIND_PATH_IMAGE_PATH, NULL, buf, len) == B_OK;
 333 }
 334
 335 //// Solaris
 336 #elif defined(__sun) || defined(sun)
 337
 338 bool getCurrentExecPath(char *buf, size_t len)
 339 {
 340         const char *exec = getexecname();
 341         if (exec == NULL)
 342                 return false;
 343
 344         if (strlcpy(buf, exec, len) >= len)
 345                 return false;
 346
 347         return true;
 348 }
 349
 350
 351 // HP-UX
 352 #elif defined(__hpux)
 353
 354 bool getCurrentExecPath(char *buf, size_t len)
 355 {
 356         struct pst_status psts;
 357
 358         if (pstat_getproc(&psts, sizeof(psts), 0, getpid()) == -1)
 359                 return false;
 360
 361         if (pstat_getpathname(buf, len, &psts.pst_fid_text) == -1)
 362                 return false;
 363
 364         return true;
 365 }
 366
 367
 368 #else
 369
 370 bool getCurrentExecPath(char *buf, size_t len)
 371 {
 372         return false;
 373 }
 374
 375 #endif
 376
 377
 378 //// Non-Windows
 379 #if !defined(_WIN32)
 380
 381 const char *getHomeOrFail()
 382 {
 383         const char *home = getenv("HOME");
 384         // In rare cases the HOME environment variable may be unset
 385         FATAL_ERROR_IF(!home,
 386                 "Required environment variable HOME is not set");
 387         return home;
 388 }
 389
 390 #endif
 391
 392
 393 //// Windows
 394 #if defined(_WIN32)
 395
 396 bool setSystemPaths()
 397 {
 398         char buf[BUFSIZ];
 399
 400         // Find path of executable and set path_share relative to it
 401         FATAL_ERROR_IF(!getCurrentExecPath(buf, sizeof(buf)),
 402                 "Failed to get current executable path");
 403         pathRemoveFile(buf, '\\');
 404
 405         std::string exepath(buf);
 406
 407         // Use ".\bin\.."
 408         path_share = exepath + "\\..";
 409         if (detectMSVCBuildDir(exepath)) {
 410                 // The msvc build dir schould normaly not be present if properly installed,
 411                 // but its usefull for debugging.
 412                 path_share += DIR_DELIM "..";
 413         }
 414
 415         // Use "C:\Users\<user>\AppData\Roaming\<PROJECT_NAME_C>"
 416         DWORD len = GetEnvironmentVariable("APPDATA", buf, sizeof(buf));
 417         FATAL_ERROR_IF(len == 0 || len > sizeof(buf), "Failed to get APPDATA");
 418
 419         path_user = std::string(buf) + DIR_DELIM + PROJECT_NAME_C;
 420         return true;
 421 }
 422
 423
 424 //// Linux
 425 #elif defined(__linux__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__DragonFly__)
 426
 427 bool setSystemPaths()
 428 {
 429         char buf[BUFSIZ];
 430
 431         if (!getCurrentExecPath(buf, sizeof(buf))) {
 432 #ifdef __ANDROID__
 433                 errorstream << "Unable to read bindir "<< std::endl;
 434 #else
 435                 FATAL_ERROR("Unable to read bindir");
 436 #endif
 437                 return false;
 438         }
 439
 440         pathRemoveFile(buf, '/');
 441         std::string bindir(buf);
 442
 443         // Find share directory from these.
 444         // It is identified by containing the subdirectory "builtin".
 445         std::list<std::string> trylist;
 446         std::string static_sharedir = STATIC_SHAREDIR;
 447         if (!static_sharedir.empty() && static_sharedir != ".")
 448                 trylist.push_back(static_sharedir);
 449
 450         trylist.push_back(bindir + DIR_DELIM ".." DIR_DELIM "share"
 451                 DIR_DELIM + PROJECT_NAME);
 452         trylist.push_back(bindir + DIR_DELIM "..");
 453
 454 #ifdef __ANDROID__
 455         trylist.push_back(path_user);
 456 #endif
 457
 458         for (std::list<std::string>::const_iterator
 459                         i = trylist.begin(); i != trylist.end(); ++i) {
 460                 const std::string &trypath = *i;
 461                 if (!fs::PathExists(trypath) ||
 462                         !fs::PathExists(trypath + DIR_DELIM + "builtin")) {
 463                         warningstream << "system-wide share not found at \""
 464                                         << trypath << "\""<< std::endl;
 465                         continue;
 466                 }
 467
 468                 // Warn if was not the first alternative
 469                 if (i != trylist.begin()) {
 470                         warningstream << "system-wide share found at \""
 471                                         << trypath << "\"" << std::endl;
 472                 }
 473
 474                 path_share = trypath;
 475                 break;
 476         }
 477
 478 #ifndef __ANDROID__
 479         path_user = std::string(getHomeOrFail()) + DIR_DELIM "."
 480                 + PROJECT_NAME;
 481 #endif
 482
 483         return true;
 484 }
 485
 486
 487 //// Mac OS X
 488 #elif defined(__APPLE__)
 489
 490 bool setSystemPaths()
 491 {
 492         CFBundleRef main_bundle = CFBundleGetMainBundle();
 493         CFURLRef resources_url = CFBundleCopyResourcesDirectoryURL(main_bundle);
 494         char path[PATH_MAX];
 495         if (CFURLGetFileSystemRepresentation(resources_url,
 496                         TRUE, (UInt8 *)path, PATH_MAX)) {
 497                 path_share = std::string(path);
 498         } else {
 499                 warningstream << "Could not determine bundle resource path" << std::endl;
 500         }
 501         CFRelease(resources_url);
 502
 503         path_user = std::string(getHomeOrFail())
 504                 + "/Library/Application Support/"
 505                 + PROJECT_NAME;
 506         return true;
 507 }
 508
 509
 510 #else
 511
 512 bool setSystemPaths()
 513 {
 514         path_share = STATIC_SHAREDIR;
 515         path_user  = std::string(getHomeOrFail()) + DIR_DELIM "."
 516                 + lowercase(PROJECT_NAME);
 517         return true;
 518 }
 519
 520
 521 #endif
 522
 523 void migrateCachePath()
 524 {
 525         const std::string local_cache_path = path_user + DIR_DELIM + "cache";
 526
 527         // Delete tmp folder if it exists (it only ever contained
 528         // a temporary ogg file, which is no longer used).
 529         if (fs::PathExists(local_cache_path + DIR_DELIM + "tmp"))
 530                 fs::RecursiveDelete(local_cache_path + DIR_DELIM + "tmp");
 531
 532         // Bail if migration impossible
 533         if (path_cache == local_cache_path || !fs::PathExists(local_cache_path)
 534                         || fs::PathExists(path_cache)) {
 535                 return;
 536         }
 537         if (!fs::Rename(local_cache_path, path_cache)) {
 538                 errorstream << "Failed to migrate local cache path "
 539                         "to system path!" << std::endl;
 540         }
 541 }
 542
 543 void initializePaths()
 544 {
 545 #if RUN_IN_PLACE
 546         char buf[BUFSIZ];
 547
 548         infostream << "Using relative paths (RUN_IN_PLACE)" << std::endl;
 549
 550         bool success =
 551                 getCurrentExecPath(buf, sizeof(buf)) ||
 552                 getExecPathFromProcfs(buf, sizeof(buf));
 553
 554         if (success) {
 555                 pathRemoveFile(buf, DIR_DELIM_CHAR);
 556                 std::string execpath(buf);
 557
 558                 path_share = execpath + DIR_DELIM "..";
 559                 path_user  = execpath + DIR_DELIM "..";
 560
 561                 if (detectMSVCBuildDir(execpath)) {
 562                         path_share += DIR_DELIM "..";
 563                         path_user  += DIR_DELIM "..";
 564                 }
 565         } else {
 566                 errorstream << "Failed to get paths by executable location, "
 567                         "trying cwd" << std::endl;
 568
 569                 if (!getCurrentWorkingDir(buf, sizeof(buf)))
 570                         FATAL_ERROR("Ran out of methods to get paths");
 571
 572                 size_t cwdlen = strlen(buf);
 573                 if (cwdlen >= 1 && buf[cwdlen - 1] == DIR_DELIM_CHAR) {
 574                         cwdlen--;
 575                         buf[cwdlen] = '\0';
 576                 }
 577
 578                 if (cwdlen >= 4 && !strcmp(buf + cwdlen - 4, DIR_DELIM "bin"))
 579                         pathRemoveFile(buf, DIR_DELIM_CHAR);
 580
 581                 std::string execpath(buf);
 582
 583                 path_share = execpath;
 584                 path_user  = execpath;
 585         }
 586         path_cache = path_user + DIR_DELIM + "cache";
 587 #else
 588         infostream << "Using system-wide paths (NOT RUN_IN_PLACE)" << std::endl;
 589
 590         if (!setSystemPaths())
 591                 errorstream << "Failed to get one or more system-wide path" << std::endl;
 592
 593
 594 #  ifdef _WIN32
 595         path_cache = path_user + DIR_DELIM + "cache";
 596 #  else
 597         // Initialize path_cache
 598         // First try $XDG_CACHE_HOME/PROJECT_NAME
 599         const char *cache_dir = getenv("XDG_CACHE_HOME");
 600         const char *home_dir = getenv("HOME");
 601         if (cache_dir) {
 602                 path_cache = std::string(cache_dir) + DIR_DELIM + PROJECT_NAME;
 603         } else if (home_dir) {
 604                 // Then try $HOME/.cache/PROJECT_NAME
 605                 path_cache = std::string(home_dir) + DIR_DELIM + ".cache"
 606                         + DIR_DELIM + PROJECT_NAME;
 607         } else {
 608                 // If neither works, use $PATH_USER/cache
 609                 path_cache = path_user + DIR_DELIM + "cache";
 610         }
 611         // Migrate cache folder to new location if possible
 612         migrateCachePath();
 613 #  endif // _WIN32
 614 #endif // RUN_IN_PLACE
 615
 616         infostream << "Detected share path: " << path_share << std::endl;
 617         infostream << "Detected user path: " << path_user << std::endl;
 618         infostream << "Detected cache path: " << path_cache << std::endl;
 619
 620 #if USE_GETTEXT
 621         bool found_localedir = false;
 622 #  ifdef STATIC_LOCALEDIR
 623         /* STATIC_LOCALEDIR may be a generalized path such as /usr/share/locale that
 624          * doesn't necessarily contain our locale files, so check data path first. */
 625         path_locale = getDataPath("locale");
 626         if (fs::PathExists(path_locale)) {
 627                 found_localedir = true;
 628                 infostream << "Using in-place locale directory " << path_locale
 629                         << " even though a static one was provided." << std::endl;
 630         } else if (STATIC_LOCALEDIR[0] && fs::PathExists(STATIC_LOCALEDIR)) {
 631                 found_localedir = true;
 632                 path_locale = STATIC_LOCALEDIR;
 633                 infostream << "Using static locale directory " << STATIC_LOCALEDIR
 634                         << std::endl;
 635         }
 636 #  else
 637         path_locale = getDataPath("locale");
 638         if (fs::PathExists(path_locale)) {
 639                 found_localedir = true;
 640         }
 641 #  endif
 642         if (!found_localedir) {
 643                 warningstream << "Couldn't find a locale directory!" << std::endl;
 644         }
 645 #endif  // USE_GETTEXT
 646 }
 647
 648 ////
 649 //// OS-specific Secure Random
 650 ////
 651
 652 #ifdef WIN32
 653
 654 bool secure_rand_fill_buf(void *buf, size_t len)
 655 {
 656         HCRYPTPROV wctx;
 657
 658         if (!CryptAcquireContext(&wctx, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
 659                 return false;
 660
 661         CryptGenRandom(wctx, len, (BYTE *)buf);
 662         CryptReleaseContext(wctx, 0);
 663         return true;
 664 }
 665
 666 #else
 667
 668 bool secure_rand_fill_buf(void *buf, size_t len)
 669 {
 670         // N.B.  This function checks *only* for /dev/urandom, because on most
 671         // common OSes it is non-blocking, whereas /dev/random is blocking, and it
 672         // is exceptionally uncommon for there to be a situation where /dev/random
 673         // exists but /dev/urandom does not.  This guesswork is necessary since
 674         // random devices are not covered by any POSIX standard...
 675         FILE *fp = fopen("/dev/urandom", "rb");
 676         if (!fp)
 677                 return false;
 678
 679         bool success = fread(buf, len, 1, fp) == 1;
 680
 681         fclose(fp);
 682         return success;
 683 }
 684
 685 #endif
 686
 687 void attachOrCreateConsole()
 688 {
 689 #ifdef _WIN32
 690         static bool consoleAllocated = false;
 691         const bool redirected = (_fileno(stdout) == -2 || _fileno(stdout) == -1); // If output is redirected to e.g a file
 692         if (!consoleAllocated && redirected && (AttachConsole(ATTACH_PARENT_PROCESS) || AllocConsole())) {
 693                 freopen("CONOUT$", "w", stdout);
 694                 freopen("CONOUT$", "w", stderr);
 695                 consoleAllocated = true;
 696         }
 697 #endif
 698 }
 699
 700 int mt_snprintf(char *buf, const size_t buf_size, const char *fmt, ...)
 701 {
 702         // https://msdn.microsoft.com/en-us/library/bt7tawza.aspx
 703         //  Many of the MSVC / Windows printf-style functions do not support positional
 704         //  arguments (eg. "%1$s"). We just forward the call to vsnprintf for sane
 705         //  platforms, but defer to _vsprintf_p on MSVC / Windows.
 706         // https://github.com/FFmpeg/FFmpeg/blob/5ae9fa13f5ac640bec113120d540f70971aa635d/compat/msvcrt/snprintf.c#L46
 707         //  _vsprintf_p has to be shimmed with _vscprintf_p on -1 (for an example see
 708         //  above FFmpeg link).
 709         va_list args;
 710         va_start(args, fmt);
 711 #ifndef _MSC_VER
 712         int c = vsnprintf(buf, buf_size, fmt, args);
 713 #else  // _MSC_VER
 714         int c = _vsprintf_p(buf, buf_size, fmt, args);
 715         if (c == -1)
 716                 c = _vscprintf_p(fmt, args);
 717 #endif // _MSC_VER
 718         va_end(args);
 719         return c;
 720 }
 721
 722 bool openURL(const std::string &url)
 723 {
 724         if ((url.substr(0, 7) != "http://" && url.substr(0, 8) != "https://") ||
 725                         url.find_first_of("\r\n") != std::string::npos) {
 726                 errorstream << "Invalid url: " << url << std::endl;
 727                 return false;
 728         }
 729
 730 #if defined(_WIN32)
 731         return (intptr_t)ShellExecuteA(NULL, NULL, url.c_str(), NULL, NULL, SW_SHOWNORMAL) > 32;
 732 #elif defined(__ANDROID__)
 733         openURLAndroid(url);
 734         return true;
 735 #elif defined(__APPLE__)
 736         const char *argv[] = {"open", url.c_str(), NULL};
 737         return posix_spawnp(NULL, "open", NULL, NULL, (char**)argv,
 738                 (*_NSGetEnviron())) == 0;
 739 #else
 740         const char *argv[] = {"xdg-open", url.c_str(), NULL};
 741         return posix_spawnp(NULL, "xdg-open", NULL, NULL, (char**)argv, environ) == 0;
 742 #endif
 743 }
 744
 745 // Load performance counter frequency only once at startup
 746 #ifdef _WIN32
 747
 748 inline double get_perf_freq()
 749 {
 750         LARGE_INTEGER freq;
 751         QueryPerformanceFrequency(&freq);
 752         return freq.QuadPart;
 753 }
 754
 755 double perf_freq = get_perf_freq();
 756
 757 #endif
 758
 759 } //namespace porting