compat/mingw.c

   1 #include "../git-compat-util.h"
   2 #include "../strbuf.h"
   3
   4 unsigned int _CRT_fmode = _O_BINARY;
   5
   6 #undef open
   7 int mingw_open (const char *filename, int oflags, ...)
   8 {
   9         va_list args;
  10         unsigned mode;
  11         va_start(args, oflags);
  12         mode = va_arg(args, int);
  13         va_end(args);
  14
  15         if (!strcmp(filename, "/dev/null"))
  16                 filename = "nul";
  17         int fd = open(filename, oflags, mode);
  18         if (fd < 0 && (oflags & O_CREAT) && errno == EACCES) {
  19                 DWORD attrs = GetFileAttributes(filename);
  20                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY))
  21                         errno = EISDIR;
  22         }
  23         return fd;
  24 }
  25
  26 static inline time_t filetime_to_time_t(const FILETIME *ft)
  27 {
  28         long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
  29         winTime -= 116444736000000000LL; /* Windows to Unix Epoch conversion */
  30         winTime /= 10000000;             /* Nano to seconds resolution */
  31         return (time_t)winTime;
  32 }
  33
  34 static inline size_t size_to_blocks(size_t s)
  35 {
  36         return (s+511)/512;
  37 }
  38
  39 extern int _getdrive( void );
  40 /* We keep the do_lstat code in a separate function to avoid recursion.
  41  * When a path ends with a slash, the stat will fail with ENOENT. In
  42  * this case, we strip the trailing slashes and stat again.
  43  */
  44 static int do_lstat(const char *file_name, struct stat *buf)
  45 {
  46         WIN32_FILE_ATTRIBUTE_DATA fdata;
  47
  48         if (GetFileAttributesExA(file_name, GetFileExInfoStandard, &fdata)) {
  49                 int fMode = S_IREAD;
  50                 if (fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
  51                         fMode |= S_IFDIR;
  52                 else
  53                         fMode |= S_IFREG;
  54                 if (!(fdata.dwFileAttributes & FILE_ATTRIBUTE_READONLY))
  55                         fMode |= S_IWRITE;
  56
  57                 buf->st_ino = 0;
  58                 buf->st_gid = 0;
  59                 buf->st_uid = 0;
  60                 buf->st_mode = fMode;
  61                 buf->st_size = fdata.nFileSizeLow; /* Can't use nFileSizeHigh, since it's not a stat64 */
  62                 buf->st_blocks = size_to_blocks(buf->st_size);
  63                 buf->st_dev = _getdrive() - 1;
  64                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
  65                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
  66                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
  67                 errno = 0;
  68                 return 0;
  69         }
  70
  71         switch (GetLastError()) {
  72         case ERROR_ACCESS_DENIED:
  73         case ERROR_SHARING_VIOLATION:
  74         case ERROR_LOCK_VIOLATION:
  75         case ERROR_SHARING_BUFFER_EXCEEDED:
  76                 errno = EACCES;
  77                 break;
  78         case ERROR_BUFFER_OVERFLOW:
  79                 errno = ENAMETOOLONG;
  80                 break;
  81         case ERROR_NOT_ENOUGH_MEMORY:
  82                 errno = ENOMEM;
  83                 break;
  84         default:
  85                 errno = ENOENT;
  86                 break;
  87         }
  88         return -1;
  89 }
  90
  91 /* We provide our own lstat/fstat functions, since the provided
  92  * lstat/fstat functions are so slow. These stat functions are
  93  * tailored for Git's usage (read: fast), and are not meant to be
  94  * complete. Note that Git stat()s are redirected to mingw_lstat()
  95  * too, since Windows doesn't really handle symlinks that well.
  96  */
  97 int mingw_lstat(const char *file_name, struct mingw_stat *buf)
  98 {
  99         int namelen;
 100         static char alt_name[PATH_MAX];
 101
 102         if (!do_lstat(file_name, buf))
 103                 return 0;
 104
 105         /* if file_name ended in a '/', Windows returned ENOENT;
 106          * try again without trailing slashes
 107          */
 108         if (errno != ENOENT)
 109                 return -1;
 110
 111         namelen = strlen(file_name);
 112         if (namelen && file_name[namelen-1] != '/')
 113                 return -1;
 114         while (namelen && file_name[namelen-1] == '/')
 115                 --namelen;
 116         if (!namelen || namelen >= PATH_MAX)
 117                 return -1;
 118
 119         memcpy(alt_name, file_name, namelen);
 120         alt_name[namelen] = 0;
 121         return do_lstat(alt_name, buf);
 122 }
 123
 124 #undef fstat
 125 #undef stat
 126 int mingw_fstat(int fd, struct mingw_stat *buf)
 127 {
 128         HANDLE fh = (HANDLE)_get_osfhandle(fd);
 129         BY_HANDLE_FILE_INFORMATION fdata;
 130
 131         if (fh == INVALID_HANDLE_VALUE) {
 132                 errno = EBADF;
 133                 return -1;
 134         }
 135         /* direct non-file handles to MS's fstat() */
 136         if (GetFileType(fh) != FILE_TYPE_DISK) {
 137                 struct stat st;
 138                 if (fstat(fd, &st))
 139                         return -1;
 140                 buf->st_ino = st.st_ino;
 141                 buf->st_gid = st.st_gid;
 142                 buf->st_uid = st.st_uid;
 143                 buf->st_mode = st.st_mode;
 144                 buf->st_size = st.st_size;
 145                 buf->st_blocks = size_to_blocks(buf->st_size);
 146                 buf->st_dev = st.st_dev;
 147                 buf->st_atime = st.st_atime;
 148                 buf->st_mtime = st.st_mtime;
 149                 buf->st_ctime = st.st_ctime;
 150                 return 0;
 151         }
 152
 153         if (GetFileInformationByHandle(fh, &fdata)) {
 154                 int fMode = S_IREAD;
 155                 if (fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
 156                         fMode |= S_IFDIR;
 157                 else
 158                         fMode |= S_IFREG;
 159                 if (!(fdata.dwFileAttributes & FILE_ATTRIBUTE_READONLY))
 160                         fMode |= S_IWRITE;
 161
 162                 buf->st_ino = 0;
 163                 buf->st_gid = 0;
 164                 buf->st_uid = 0;
 165                 buf->st_mode = fMode;
 166                 buf->st_size = fdata.nFileSizeLow; /* Can't use nFileSizeHigh, since it's not a stat64 */
 167                 buf->st_blocks = size_to_blocks(buf->st_size);
 168                 buf->st_dev = _getdrive() - 1;
 169                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
 170                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
 171                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
 172                 return 0;
 173         }
 174         errno = EBADF;
 175         return -1;
 176 }
 177
 178 static inline void time_t_to_filetime(time_t t, FILETIME *ft)
 179 {
 180         long long winTime = t * 10000000LL + 116444736000000000LL;
 181         ft->dwLowDateTime = winTime;
 182         ft->dwHighDateTime = winTime >> 32;
 183 }
 184
 185 int mingw_utime (const char *file_name, const struct utimbuf *times)
 186 {
 187         FILETIME mft, aft;
 188         int fh, rc;
 189
 190         /* must have write permission */
 191         if ((fh = open(file_name, O_RDWR | O_BINARY)) < 0)
 192                 return -1;
 193
 194         time_t_to_filetime(times->modtime, &mft);
 195         time_t_to_filetime(times->actime, &aft);
 196         if (!SetFileTime((HANDLE)_get_osfhandle(fh), NULL, &aft, &mft)) {
 197                 errno = EINVAL;
 198                 rc = -1;
 199         } else
 200                 rc = 0;
 201         close(fh);
 202         return rc;
 203 }
 204
 205 unsigned int sleep (unsigned int seconds)
 206 {
 207         Sleep(seconds*1000);
 208         return 0;
 209 }
 210
 211 int mkstemp(char *template)
 212 {
 213         char *filename = mktemp(template);
 214         if (filename == NULL)
 215                 return -1;
 216         return open(filename, O_RDWR | O_CREAT, 0600);
 217 }
 218
 219 int gettimeofday(struct timeval *tv, void *tz)
 220 {
 221         SYSTEMTIME st;
 222         struct tm tm;
 223         GetSystemTime(&st);
 224         tm.tm_year = st.wYear-1900;
 225         tm.tm_mon = st.wMonth-1;
 226         tm.tm_mday = st.wDay;
 227         tm.tm_hour = st.wHour;
 228         tm.tm_min = st.wMinute;
 229         tm.tm_sec = st.wSecond;
 230         tv->tv_sec = tm_to_time_t(&tm);
 231         if (tv->tv_sec < 0)
 232                 return -1;
 233         tv->tv_usec = st.wMilliseconds*1000;
 234         return 0;
 235 }
 236
 237 int pipe(int filedes[2])
 238 {
 239         int fd;
 240         HANDLE h[2], parent;
 241
 242         if (_pipe(filedes, 8192, 0) < 0)
 243                 return -1;
 244
 245         parent = GetCurrentProcess();
 246
 247         if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[0]),
 248                         parent, &h[0], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
 249                 close(filedes[0]);
 250                 close(filedes[1]);
 251                 return -1;
 252         }
 253         if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[1]),
 254                         parent, &h[1], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
 255                 close(filedes[0]);
 256                 close(filedes[1]);
 257                 CloseHandle(h[0]);
 258                 return -1;
 259         }
 260         fd = _open_osfhandle((int)h[0], O_NOINHERIT);
 261         if (fd < 0) {
 262                 close(filedes[0]);
 263                 close(filedes[1]);
 264                 CloseHandle(h[0]);
 265                 CloseHandle(h[1]);
 266                 return -1;
 267         }
 268         close(filedes[0]);
 269         filedes[0] = fd;
 270         fd = _open_osfhandle((int)h[1], O_NOINHERIT);
 271         if (fd < 0) {
 272                 close(filedes[0]);
 273                 close(filedes[1]);
 274                 CloseHandle(h[1]);
 275                 return -1;
 276         }
 277         close(filedes[1]);
 278         filedes[1] = fd;
 279         return 0;
 280 }
 281
 282 int poll(struct pollfd *ufds, unsigned int nfds, int timeout)
 283 {
 284         int i, pending;
 285
 286         if (timeout != -1)
 287                 return errno = EINVAL, error("poll timeout not supported");
 288
 289         /* When there is only one fd to wait for, then we pretend that
 290          * input is available and let the actual wait happen when the
 291          * caller invokes read().
 292          */
 293         if (nfds == 1) {
 294                 if (!(ufds[0].events & POLLIN))
 295                         return errno = EINVAL, error("POLLIN not set");
 296                 ufds[0].revents = POLLIN;
 297                 return 0;
 298         }
 299
 300 repeat:
 301         pending = 0;
 302         for (i = 0; i < nfds; i++) {
 303                 DWORD avail = 0;
 304                 HANDLE h = (HANDLE) _get_osfhandle(ufds[i].fd);
 305                 if (h == INVALID_HANDLE_VALUE)
 306                         return -1;      /* errno was set */
 307
 308                 if (!(ufds[i].events & POLLIN))
 309                         return errno = EINVAL, error("POLLIN not set");
 310
 311                 /* this emulation works only for pipes */
 312                 if (!PeekNamedPipe(h, NULL, 0, NULL, &avail, NULL)) {
 313                         int err = GetLastError();
 314                         if (err == ERROR_BROKEN_PIPE) {
 315                                 ufds[i].revents = POLLHUP;
 316                                 pending++;
 317                         } else {
 318                                 errno = EINVAL;
 319                                 return error("PeekNamedPipe failed,"
 320                                         " GetLastError: %u", err);
 321                         }
 322                 } else if (avail) {
 323                         ufds[i].revents = POLLIN;
 324                         pending++;
 325                 } else
 326                         ufds[i].revents = 0;
 327         }
 328         if (!pending) {
 329                 /* The only times that we spin here is when the process
 330                  * that is connected through the pipes is waiting for
 331                  * its own input data to become available. But since
 332                  * the process (pack-objects) is itself CPU intensive,
 333                  * it will happily pick up the time slice that we are
 334                  * relinguishing here.
 335                  */
 336                 Sleep(0);
 337                 goto repeat;
 338         }
 339         return 0;
 340 }
 341
 342 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 343 {
 344         /* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 345         memcpy(result, gmtime(timep), sizeof(struct tm));
 346         return result;
 347 }
 348
 349 struct tm *localtime_r(const time_t *timep, struct tm *result)
 350 {
 351         /* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 352         memcpy(result, localtime(timep), sizeof(struct tm));
 353         return result;
 354 }
 355
 356 #undef getcwd
 357 char *mingw_getcwd(char *pointer, int len)
 358 {
 359         int i;
 360         char *ret = getcwd(pointer, len);
 361         if (!ret)
 362                 return ret;
 363         for (i = 0; pointer[i]; i++)
 364                 if (pointer[i] == '\\')
 365                         pointer[i] = '/';
 366         return ret;
 367 }
 368
 369 #undef getenv
 370 char *mingw_getenv(const char *name)
 371 {
 372         char *result = getenv(name);
 373         if (!result && !strcmp(name, "TMPDIR")) {
 374                 /* on Windows it is TMP and TEMP */
 375                 result = getenv("TMP");
 376                 if (!result)
 377                         result = getenv("TEMP");
 378         }
 379         return result;
 380 }
 381
 382 /*
 383  * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
 384  * (Parsing C++ Command-Line Arguments)
 385  */
 386 static const char *quote_arg(const char *arg)
 387 {
 388         /* count chars to quote */
 389         int len = 0, n = 0;
 390         int force_quotes = 0;
 391         char *q, *d;
 392         const char *p = arg;
 393         if (!*p) force_quotes = 1;
 394         while (*p) {
 395                 if (isspace(*p) || *p == '*' || *p == '?' || *p == '{')
 396                         force_quotes = 1;
 397                 else if (*p == '"')
 398                         n++;
 399                 else if (*p == '\\') {
 400                         int count = 0;
 401                         while (*p == '\\') {
 402                                 count++;
 403                                 p++;
 404                                 len++;
 405                         }
 406                         if (*p == '"')
 407                                 n += count*2 + 1;
 408                         continue;
 409                 }
 410                 len++;
 411                 p++;
 412         }
 413         if (!force_quotes && n == 0)
 414                 return arg;
 415
 416         /* insert \ where necessary */
 417         d = q = xmalloc(len+n+3);
 418         *d++ = '"';
 419         while (*arg) {
 420                 if (*arg == '"')
 421                         *d++ = '\\';
 422                 else if (*arg == '\\') {
 423                         int count = 0;
 424                         while (*arg == '\\') {
 425                                 count++;
 426                                 *d++ = *arg++;
 427                         }
 428                         if (*arg == '"') {
 429                                 while (count-- > 0)
 430                                         *d++ = '\\';
 431                                 *d++ = '\\';
 432                         }
 433                 }
 434                 *d++ = *arg++;
 435         }
 436         *d++ = '"';
 437         *d++ = 0;
 438         return q;
 439 }
 440
 441 static const char *parse_interpreter(const char *cmd)
 442 {
 443         static char buf[100];
 444         char *p, *opt;
 445         int n, fd;
 446
 447         /* don't even try a .exe */
 448         n = strlen(cmd);
 449         if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
 450                 return NULL;
 451
 452         fd = open(cmd, O_RDONLY);
 453         if (fd < 0)
 454                 return NULL;
 455         n = read(fd, buf, sizeof(buf)-1);
 456         close(fd);
 457         if (n < 4)      /* at least '#!/x' and not error */
 458                 return NULL;
 459
 460         if (buf[0] != '#' || buf[1] != '!')
 461                 return NULL;
 462         buf[n] = '\0';
 463         p = strchr(buf, '\n');
 464         if (!p)
 465                 return NULL;
 466
 467         *p = '\0';
 468         if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
 469                 return NULL;
 470         /* strip options */
 471         if ((opt = strchr(p+1, ' ')))
 472                 *opt = '\0';
 473         return p+1;
 474 }
 475
 476 /*
 477  * Splits the PATH into parts.
 478  */
 479 static char **get_path_split(void)
 480 {
 481         char *p, **path, *envpath = getenv("PATH");
 482         int i, n = 0;
 483
 484         if (!envpath || !*envpath)
 485                 return NULL;
 486
 487         envpath = xstrdup(envpath);
 488         p = envpath;
 489         while (p) {
 490                 char *dir = p;
 491                 p = strchr(p, ';');
 492                 if (p) *p++ = '\0';
 493                 if (*dir) {     /* not earlier, catches series of ; */
 494                         ++n;
 495                 }
 496         }
 497         if (!n)
 498                 return NULL;
 499
 500         path = xmalloc((n+1)*sizeof(char*));
 501         p = envpath;
 502         i = 0;
 503         do {
 504                 if (*p)
 505                         path[i++] = xstrdup(p);
 506                 p = p+strlen(p)+1;
 507         } while (i < n);
 508         path[i] = NULL;
 509
 510         free(envpath);
 511
 512         return path;
 513 }
 514
 515 static void free_path_split(char **path)
 516 {
 517         if (!path)
 518                 return;
 519
 520         char **p = path;
 521         while (*p)
 522                 free(*p++);
 523         free(path);
 524 }
 525
 526 /*
 527  * exe_only means that we only want to detect .exe files, but not scripts
 528  * (which do not have an extension)
 529  */
 530 static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
 531 {
 532         char path[MAX_PATH];
 533         snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
 534
 535         if (!isexe && access(path, F_OK) == 0)
 536                 return xstrdup(path);
 537         path[strlen(path)-4] = '\0';
 538         if ((!exe_only || isexe) && access(path, F_OK) == 0)
 539                 if (!(GetFileAttributes(path) & FILE_ATTRIBUTE_DIRECTORY))
 540                         return xstrdup(path);
 541         return NULL;
 542 }
 543
 544 /*
 545  * Determines the absolute path of cmd using the the split path in path.
 546  * If cmd contains a slash or backslash, no lookup is performed.
 547  */
 548 static char *path_lookup(const char *cmd, char **path, int exe_only)
 549 {
 550         char *prog = NULL;
 551         int len = strlen(cmd);
 552         int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 553
 554         if (strchr(cmd, '/') || strchr(cmd, '\\'))
 555                 prog = xstrdup(cmd);
 556
 557         while (!prog && *path)
 558                 prog = lookup_prog(*path++, cmd, isexe, exe_only);
 559
 560         return prog;
 561 }
 562
 563 static int env_compare(const void *a, const void *b)
 564 {
 565         char *const *ea = a;
 566         char *const *eb = b;
 567         return strcasecmp(*ea, *eb);
 568 }
 569
 570 static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
 571                            int prepend_cmd)
 572 {
 573         STARTUPINFO si;
 574         PROCESS_INFORMATION pi;
 575         struct strbuf envblk, args;
 576         unsigned flags;
 577         BOOL ret;
 578
 579         /* Determine whether or not we are associated to a console */
 580         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
 581                         FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 582                         FILE_ATTRIBUTE_NORMAL, NULL);
 583         if (cons == INVALID_HANDLE_VALUE) {
 584                 /* There is no console associated with this process.
 585                  * Since the child is a console process, Windows
 586                  * would normally create a console window. But
 587                  * since we'll be redirecting std streams, we do
 588                  * not need the console.
 589                  */
 590                 flags = CREATE_NO_WINDOW;
 591         } else {
 592                 /* There is already a console. If we specified
 593                  * CREATE_NO_WINDOW here, too, Windows would
 594                  * disassociate the child from the console.
 595                  * Go figure!
 596                  */
 597                 flags = 0;
 598                 CloseHandle(cons);
 599         }
 600         memset(&si, 0, sizeof(si));
 601         si.cb = sizeof(si);
 602         si.dwFlags = STARTF_USESTDHANDLES;
 603         si.hStdInput = (HANDLE) _get_osfhandle(0);
 604         si.hStdOutput = (HANDLE) _get_osfhandle(1);
 605         si.hStdError = (HANDLE) _get_osfhandle(2);
 606
 607         /* concatenate argv, quoting args as we go */
 608         strbuf_init(&args, 0);
 609         if (prepend_cmd) {
 610                 char *quoted = (char *)quote_arg(cmd);
 611                 strbuf_addstr(&args, quoted);
 612                 if (quoted != cmd)
 613                         free(quoted);
 614         }
 615         for (; *argv; argv++) {
 616                 char *quoted = (char *)quote_arg(*argv);
 617                 if (*args.buf)
 618                         strbuf_addch(&args, ' ');
 619                 strbuf_addstr(&args, quoted);
 620                 if (quoted != *argv)
 621                         free(quoted);
 622         }
 623
 624         if (env) {
 625                 int count = 0;
 626                 char **e, **sorted_env;
 627
 628                 for (e = env; *e; e++)
 629                         count++;
 630
 631                 /* environment must be sorted */
 632                 sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
 633                 memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
 634                 qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
 635
 636                 strbuf_init(&envblk, 0);
 637                 for (e = sorted_env; *e; e++) {
 638                         strbuf_addstr(&envblk, *e);
 639                         strbuf_addch(&envblk, '\0');
 640                 }
 641                 free(sorted_env);
 642         }
 643
 644         memset(&pi, 0, sizeof(pi));
 645         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
 646                 env ? envblk.buf : NULL, NULL, &si, &pi);
 647
 648         if (env)
 649                 strbuf_release(&envblk);
 650         strbuf_release(&args);
 651
 652         if (!ret) {
 653                 errno = ENOENT;
 654                 return -1;
 655         }
 656         CloseHandle(pi.hThread);
 657         return (pid_t)pi.hProcess;
 658 }
 659
 660 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env)
 661 {
 662         pid_t pid;
 663         char **path = get_path_split();
 664         char *prog = path_lookup(cmd, path, 0);
 665
 666         if (!prog) {
 667                 errno = ENOENT;
 668                 pid = -1;
 669         }
 670         else {
 671                 const char *interpr = parse_interpreter(prog);
 672
 673                 if (interpr) {
 674                         const char *argv0 = argv[0];
 675                         char *iprog = path_lookup(interpr, path, 1);
 676                         argv[0] = prog;
 677                         if (!iprog) {
 678                                 errno = ENOENT;
 679                                 pid = -1;
 680                         }
 681                         else {
 682                                 pid = mingw_spawnve(iprog, argv, env, 1);
 683                                 free(iprog);
 684                         }
 685                         argv[0] = argv0;
 686                 }
 687                 else
 688                         pid = mingw_spawnve(prog, argv, env, 0);
 689                 free(prog);
 690         }
 691         free_path_split(path);
 692         return pid;
 693 }
 694
 695 static int try_shell_exec(const char *cmd, char *const *argv, char **env)
 696 {
 697         const char *interpr = parse_interpreter(cmd);
 698         char **path;
 699         char *prog;
 700         int pid = 0;
 701
 702         if (!interpr)
 703                 return 0;
 704         path = get_path_split();
 705         prog = path_lookup(interpr, path, 1);
 706         if (prog) {
 707                 int argc = 0;
 708                 const char **argv2;
 709                 while (argv[argc]) argc++;
 710                 argv2 = xmalloc(sizeof(*argv) * (argc+1));
 711                 argv2[0] = (char *)cmd; /* full path to the script file */
 712                 memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
 713                 pid = mingw_spawnve(prog, argv2, env, 1);
 714                 if (pid >= 0) {
 715                         int status;
 716                         if (waitpid(pid, &status, 0) < 0)
 717                                 status = 255;
 718                         exit(status);
 719                 }
 720                 pid = 1;        /* indicate that we tried but failed */
 721                 free(prog);
 722                 free(argv2);
 723         }
 724         free_path_split(path);
 725         return pid;
 726 }
 727
 728 static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
 729 {
 730         /* check if git_command is a shell script */
 731         if (!try_shell_exec(cmd, argv, (char **)env)) {
 732                 int pid, status;
 733
 734                 pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
 735                 if (pid < 0)
 736                         return;
 737                 if (waitpid(pid, &status, 0) < 0)
 738                         status = 255;
 739                 exit(status);
 740         }
 741 }
 742
 743 void mingw_execvp(const char *cmd, char *const *argv)
 744 {
 745         char **path = get_path_split();
 746         char *prog = path_lookup(cmd, path, 0);
 747
 748         if (prog) {
 749                 mingw_execve(prog, argv, environ);
 750                 free(prog);
 751         } else
 752                 errno = ENOENT;
 753
 754         free_path_split(path);
 755 }
 756
 757 char **copy_environ()
 758 {
 759         char **env;
 760         int i = 0;
 761         while (environ[i])
 762                 i++;
 763         env = xmalloc((i+1)*sizeof(*env));
 764         for (i = 0; environ[i]; i++)
 765                 env[i] = xstrdup(environ[i]);
 766         env[i] = NULL;
 767         return env;
 768 }
 769
 770 void free_environ(char **env)
 771 {
 772         int i;
 773         for (i = 0; env[i]; i++)
 774                 free(env[i]);
 775         free(env);
 776 }
 777
 778 static int lookup_env(char **env, const char *name, size_t nmln)
 779 {
 780         int i;
 781
 782         for (i = 0; env[i]; i++) {
 783                 if (0 == strncmp(env[i], name, nmln)
 784                     && '=' == env[i][nmln])
 785                         /* matches */
 786                         return i;
 787         }
 788         return -1;
 789 }
 790
 791 /*
 792  * If name contains '=', then sets the variable, otherwise it unsets it
 793  */
 794 char **env_setenv(char **env, const char *name)
 795 {
 796         char *eq = strchrnul(name, '=');
 797         int i = lookup_env(env, name, eq-name);
 798
 799         if (i < 0) {
 800                 if (*eq) {
 801                         for (i = 0; env[i]; i++)
 802                                 ;
 803                         env = xrealloc(env, (i+2)*sizeof(*env));
 804                         env[i] = xstrdup(name);
 805                         env[i+1] = NULL;
 806                 }
 807         }
 808         else {
 809                 free(env[i]);
 810                 if (*eq)
 811                         env[i] = xstrdup(name);
 812                 else
 813                         for (; env[i]; i++)
 814                                 env[i] = env[i+1];
 815         }
 816         return env;
 817 }
 818
 819 /* this is the first function to call into WS_32; initialize it */
 820 #undef gethostbyname
 821 struct hostent *mingw_gethostbyname(const char *host)
 822 {
 823         WSADATA wsa;
 824
 825         if (WSAStartup(MAKEWORD(2,2), &wsa))
 826                 die("unable to initialize winsock subsystem, error %d",
 827                         WSAGetLastError());
 828         atexit((void(*)(void)) WSACleanup);
 829         return gethostbyname(host);
 830 }
 831
 832 int mingw_socket(int domain, int type, int protocol)
 833 {
 834         int sockfd;
 835         SOCKET s = WSASocket(domain, type, protocol, NULL, 0, 0);
 836         if (s == INVALID_SOCKET) {
 837                 /*
 838                  * WSAGetLastError() values are regular BSD error codes
 839                  * biased by WSABASEERR.
 840                  * However, strerror() does not know about networking
 841                  * specific errors, which are values beginning at 38 or so.
 842                  * Therefore, we choose to leave the biased error code
 843                  * in errno so that _if_ someone looks up the code somewhere,
 844                  * then it is at least the number that are usually listed.
 845                  */
 846                 errno = WSAGetLastError();
 847                 return -1;
 848         }
 849         /* convert into a file descriptor */
 850         if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
 851                 closesocket(s);
 852                 return error("unable to make a socket file descriptor: %s",
 853                         strerror(errno));
 854         }
 855         return sockfd;
 856 }
 857
 858 #undef connect
 859 int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
 860 {
 861         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
 862         return connect(s, sa, sz);
 863 }
 864
 865 #undef rename
 866 int mingw_rename(const char *pold, const char *pnew)
 867 {
 868         DWORD attrs;
 869
 870         /*
 871          * Try native rename() first to get errno right.
 872          * It is based on MoveFile(), which cannot overwrite existing files.
 873          */
 874         if (!rename(pold, pnew))
 875                 return 0;
 876         if (errno != EEXIST)
 877                 return -1;
 878         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
 879                 return 0;
 880         /* TODO: translate more errors */
 881         if (GetLastError() == ERROR_ACCESS_DENIED &&
 882             (attrs = GetFileAttributes(pnew)) != INVALID_FILE_ATTRIBUTES) {
 883                 if (attrs & FILE_ATTRIBUTE_DIRECTORY) {
 884                         errno = EISDIR;
 885                         return -1;
 886                 }
 887                 if ((attrs & FILE_ATTRIBUTE_READONLY) &&
 888                     SetFileAttributes(pnew, attrs & ~FILE_ATTRIBUTE_READONLY)) {
 889                         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
 890                                 return 0;
 891                         /* revert file attributes on failure */
 892                         SetFileAttributes(pnew, attrs);
 893                 }
 894         }
 895         errno = EACCES;
 896         return -1;
 897 }
 898
 899 struct passwd *getpwuid(int uid)
 900 {
 901         static char user_name[100];
 902         static struct passwd p;
 903
 904         DWORD len = sizeof(user_name);
 905         if (!GetUserName(user_name, &len))
 906                 return NULL;
 907         p.pw_name = user_name;
 908         p.pw_gecos = "unknown";
 909         p.pw_dir = NULL;
 910         return &p;
 911 }
 912
 913 static HANDLE timer_event;
 914 static HANDLE timer_thread;
 915 static int timer_interval;
 916 static int one_shot;
 917 static sig_handler_t timer_fn = SIG_DFL;
 918
 919 /* The timer works like this:
 920  * The thread, ticktack(), is a trivial routine that most of the time
 921  * only waits to receive the signal to terminate. The main thread tells
 922  * the thread to terminate by setting the timer_event to the signalled
 923  * state.
 924  * But ticktack() interrupts the wait state after the timer's interval
 925  * length to call the signal handler.
 926  */
 927
 928 static __stdcall unsigned ticktack(void *dummy)
 929 {
 930         while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
 931                 if (timer_fn == SIG_DFL)
 932                         die("Alarm");
 933                 if (timer_fn != SIG_IGN)
 934                         timer_fn(SIGALRM);
 935                 if (one_shot)
 936                         break;
 937         }
 938         return 0;
 939 }
 940
 941 static int start_timer_thread(void)
 942 {
 943         timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 944         if (timer_event) {
 945                 timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
 946                 if (!timer_thread )
 947                         return errno = ENOMEM,
 948                                 error("cannot start timer thread");
 949         } else
 950                 return errno = ENOMEM,
 951                         error("cannot allocate resources for timer");
 952         return 0;
 953 }
 954
 955 static void stop_timer_thread(void)
 956 {
 957         if (timer_event)
 958                 SetEvent(timer_event);  /* tell thread to terminate */
 959         if (timer_thread) {
 960                 int rc = WaitForSingleObject(timer_thread, 1000);
 961                 if (rc == WAIT_TIMEOUT)
 962                         error("timer thread did not terminate timely");
 963                 else if (rc != WAIT_OBJECT_0)
 964                         error("waiting for timer thread failed: %lu",
 965                               GetLastError());
 966                 CloseHandle(timer_thread);
 967         }
 968         if (timer_event)
 969                 CloseHandle(timer_event);
 970         timer_event = NULL;
 971         timer_thread = NULL;
 972 }
 973
 974 static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
 975 {
 976         return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
 977 }
 978
 979 int setitimer(int type, struct itimerval *in, struct itimerval *out)
 980 {
 981         static const struct timeval zero;
 982         static int atexit_done;
 983
 984         if (out != NULL)
 985                 return errno = EINVAL,
 986                         error("setitimer param 3 != NULL not implemented");
 987         if (!is_timeval_eq(&in->it_interval, &zero) &&
 988             !is_timeval_eq(&in->it_interval, &in->it_value))
 989                 return errno = EINVAL,
 990                         error("setitimer: it_interval must be zero or eq it_value");
 991
 992         if (timer_thread)
 993                 stop_timer_thread();
 994
 995         if (is_timeval_eq(&in->it_value, &zero) &&
 996             is_timeval_eq(&in->it_interval, &zero))
 997                 return 0;
 998
 999         timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
1000         one_shot = is_timeval_eq(&in->it_interval, &zero);
1001         if (!atexit_done) {
1002                 atexit(stop_timer_thread);
1003                 atexit_done = 1;
1004         }
1005         return start_timer_thread();
1006 }
1007
1008 int sigaction(int sig, struct sigaction *in, struct sigaction *out)
1009 {
1010         if (sig != SIGALRM)
1011                 return errno = EINVAL,
1012                         error("sigaction only implemented for SIGALRM");
1013         if (out != NULL)
1014                 return errno = EINVAL,
1015                         error("sigaction: param 3 != NULL not implemented");
1016
1017         timer_fn = in->sa_handler;
1018         return 0;
1019 }
1020
1021 #undef signal
1022 sig_handler_t mingw_signal(int sig, sig_handler_t handler)
1023 {
1024         if (sig != SIGALRM)
1025                 return signal(sig, handler);
1026         sig_handler_t old = timer_fn;
1027         timer_fn = handler;
1028         return old;
1029 }
1030
1031 static const char *make_backslash_path(const char *path)
1032 {
1033         static char buf[PATH_MAX + 1];
1034         char *c;
1035
1036         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
1037                 die("Too long path: %.*s", 60, path);
1038
1039         for (c = buf; *c; c++) {
1040                 if (*c == '/')
1041                         *c = '\\';
1042         }
1043         return buf;
1044 }
1045
1046 void mingw_open_html(const char *unixpath)
1047 {
1048         const char *htmlpath = make_backslash_path(unixpath);
1049         printf("Launching default browser to display HTML ...\n");
1050         ShellExecute(NULL, "open", htmlpath, NULL, "\\", 0);
1051 }