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