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