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 /*
 370  * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
 371  * (Parsing C++ Command-Line Arguments)
 372  */
 373 static const char *quote_arg(const char *arg)
 374 {
 375         /* count chars to quote */
 376         int len = 0, n = 0;
 377         int force_quotes = 0;
 378         char *q, *d;
 379         const char *p = arg;
 380         if (!*p) force_quotes = 1;
 381         while (*p) {
 382                 if (isspace(*p) || *p == '*' || *p == '?' || *p == '{')
 383                         force_quotes = 1;
 384                 else if (*p == '"')
 385                         n++;
 386                 else if (*p == '\\') {
 387                         int count = 0;
 388                         while (*p == '\\') {
 389                                 count++;
 390                                 p++;
 391                                 len++;
 392                         }
 393                         if (*p == '"')
 394                                 n += count*2 + 1;
 395                         continue;
 396                 }
 397                 len++;
 398                 p++;
 399         }
 400         if (!force_quotes && n == 0)
 401                 return arg;
 402
 403         /* insert \ where necessary */
 404         d = q = xmalloc(len+n+3);
 405         *d++ = '"';
 406         while (*arg) {
 407                 if (*arg == '"')
 408                         *d++ = '\\';
 409                 else if (*arg == '\\') {
 410                         int count = 0;
 411                         while (*arg == '\\') {
 412                                 count++;
 413                                 *d++ = *arg++;
 414                         }
 415                         if (*arg == '"') {
 416                                 while (count-- > 0)
 417                                         *d++ = '\\';
 418                                 *d++ = '\\';
 419                         }
 420                 }
 421                 *d++ = *arg++;
 422         }
 423         *d++ = '"';
 424         *d++ = 0;
 425         return q;
 426 }
 427
 428 static const char *parse_interpreter(const char *cmd)
 429 {
 430         static char buf[100];
 431         char *p, *opt;
 432         int n, fd;
 433
 434         /* don't even try a .exe */
 435         n = strlen(cmd);
 436         if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
 437                 return NULL;
 438
 439         fd = open(cmd, O_RDONLY);
 440         if (fd < 0)
 441                 return NULL;
 442         n = read(fd, buf, sizeof(buf)-1);
 443         close(fd);
 444         if (n < 4)      /* at least '#!/x' and not error */
 445                 return NULL;
 446
 447         if (buf[0] != '#' || buf[1] != '!')
 448                 return NULL;
 449         buf[n] = '\0';
 450         p = strchr(buf, '\n');
 451         if (!p)
 452                 return NULL;
 453
 454         *p = '\0';
 455         if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
 456                 return NULL;
 457         /* strip options */
 458         if ((opt = strchr(p+1, ' ')))
 459                 *opt = '\0';
 460         return p+1;
 461 }
 462
 463 /*
 464  * Splits the PATH into parts.
 465  */
 466 static char **get_path_split(void)
 467 {
 468         char *p, **path, *envpath = getenv("PATH");
 469         int i, n = 0;
 470
 471         if (!envpath || !*envpath)
 472                 return NULL;
 473
 474         envpath = xstrdup(envpath);
 475         p = envpath;
 476         while (p) {
 477                 char *dir = p;
 478                 p = strchr(p, ';');
 479                 if (p) *p++ = '\0';
 480                 if (*dir) {     /* not earlier, catches series of ; */
 481                         ++n;
 482                 }
 483         }
 484         if (!n)
 485                 return NULL;
 486
 487         path = xmalloc((n+1)*sizeof(char*));
 488         p = envpath;
 489         i = 0;
 490         do {
 491                 if (*p)
 492                         path[i++] = xstrdup(p);
 493                 p = p+strlen(p)+1;
 494         } while (i < n);
 495         path[i] = NULL;
 496
 497         free(envpath);
 498
 499         return path;
 500 }
 501
 502 static void free_path_split(char **path)
 503 {
 504         if (!path)
 505                 return;
 506
 507         char **p = path;
 508         while (*p)
 509                 free(*p++);
 510         free(path);
 511 }
 512
 513 /*
 514  * exe_only means that we only want to detect .exe files, but not scripts
 515  * (which do not have an extension)
 516  */
 517 static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
 518 {
 519         char path[MAX_PATH];
 520         snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
 521
 522         if (!isexe && access(path, F_OK) == 0)
 523                 return xstrdup(path);
 524         path[strlen(path)-4] = '\0';
 525         if ((!exe_only || isexe) && access(path, F_OK) == 0)
 526                 return xstrdup(path);
 527         return NULL;
 528 }
 529
 530 /*
 531  * Determines the absolute path of cmd using the the split path in path.
 532  * If cmd contains a slash or backslash, no lookup is performed.
 533  */
 534 static char *path_lookup(const char *cmd, char **path, int exe_only)
 535 {
 536         char *prog = NULL;
 537         int len = strlen(cmd);
 538         int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 539
 540         if (strchr(cmd, '/') || strchr(cmd, '\\'))
 541                 prog = xstrdup(cmd);
 542
 543         while (!prog && *path)
 544                 prog = lookup_prog(*path++, cmd, isexe, exe_only);
 545
 546         return prog;
 547 }
 548
 549 static int env_compare(const void *a, const void *b)
 550 {
 551         char *const *ea = a;
 552         char *const *eb = b;
 553         return strcasecmp(*ea, *eb);
 554 }
 555
 556 static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
 557                            int prepend_cmd)
 558 {
 559         STARTUPINFO si;
 560         PROCESS_INFORMATION pi;
 561         struct strbuf envblk, args;
 562         unsigned flags;
 563         BOOL ret;
 564
 565         /* Determine whether or not we are associated to a console */
 566         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
 567                         FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 568                         FILE_ATTRIBUTE_NORMAL, NULL);
 569         if (cons == INVALID_HANDLE_VALUE) {
 570                 /* There is no console associated with this process.
 571                  * Since the child is a console process, Windows
 572                  * would normally create a console window. But
 573                  * since we'll be redirecting std streams, we do
 574                  * not need the console.
 575                  */
 576                 flags = CREATE_NO_WINDOW;
 577         } else {
 578                 /* There is already a console. If we specified
 579                  * CREATE_NO_WINDOW here, too, Windows would
 580                  * disassociate the child from the console.
 581                  * Go figure!
 582                  */
 583                 flags = 0;
 584                 CloseHandle(cons);
 585         }
 586         memset(&si, 0, sizeof(si));
 587         si.cb = sizeof(si);
 588         si.dwFlags = STARTF_USESTDHANDLES;
 589         si.hStdInput = (HANDLE) _get_osfhandle(0);
 590         si.hStdOutput = (HANDLE) _get_osfhandle(1);
 591         si.hStdError = (HANDLE) _get_osfhandle(2);
 592
 593         /* concatenate argv, quoting args as we go */
 594         strbuf_init(&args, 0);
 595         if (prepend_cmd) {
 596                 char *quoted = (char *)quote_arg(cmd);
 597                 strbuf_addstr(&args, quoted);
 598                 if (quoted != cmd)
 599                         free(quoted);
 600         }
 601         for (; *argv; argv++) {
 602                 char *quoted = (char *)quote_arg(*argv);
 603                 if (*args.buf)
 604                         strbuf_addch(&args, ' ');
 605                 strbuf_addstr(&args, quoted);
 606                 if (quoted != *argv)
 607                         free(quoted);
 608         }
 609
 610         if (env) {
 611                 int count = 0;
 612                 char **e, **sorted_env;
 613
 614                 for (e = env; *e; e++)
 615                         count++;
 616
 617                 /* environment must be sorted */
 618                 sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
 619                 memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
 620                 qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
 621
 622                 strbuf_init(&envblk, 0);
 623                 for (e = sorted_env; *e; e++) {
 624                         strbuf_addstr(&envblk, *e);
 625                         strbuf_addch(&envblk, '\0');
 626                 }
 627                 free(sorted_env);
 628         }
 629
 630         memset(&pi, 0, sizeof(pi));
 631         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
 632                 env ? envblk.buf : NULL, NULL, &si, &pi);
 633
 634         if (env)
 635                 strbuf_release(&envblk);
 636         strbuf_release(&args);
 637
 638         if (!ret) {
 639                 errno = ENOENT;
 640                 return -1;
 641         }
 642         CloseHandle(pi.hThread);
 643         return (pid_t)pi.hProcess;
 644 }
 645
 646 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env)
 647 {
 648         pid_t pid;
 649         char **path = get_path_split();
 650         char *prog = path_lookup(cmd, path, 0);
 651
 652         if (!prog) {
 653                 errno = ENOENT;
 654                 pid = -1;
 655         }
 656         else {
 657                 const char *interpr = parse_interpreter(prog);
 658
 659                 if (interpr) {
 660                         const char *argv0 = argv[0];
 661                         char *iprog = path_lookup(interpr, path, 1);
 662                         argv[0] = prog;
 663                         if (!iprog) {
 664                                 errno = ENOENT;
 665                                 pid = -1;
 666                         }
 667                         else {
 668                                 pid = mingw_spawnve(iprog, argv, env, 1);
 669                                 free(iprog);
 670                         }
 671                         argv[0] = argv0;
 672                 }
 673                 else
 674                         pid = mingw_spawnve(prog, argv, env, 0);
 675                 free(prog);
 676         }
 677         free_path_split(path);
 678         return pid;
 679 }
 680
 681 static int try_shell_exec(const char *cmd, char *const *argv, char **env)
 682 {
 683         const char *interpr = parse_interpreter(cmd);
 684         char **path;
 685         char *prog;
 686         int pid = 0;
 687
 688         if (!interpr)
 689                 return 0;
 690         path = get_path_split();
 691         prog = path_lookup(interpr, path, 1);
 692         if (prog) {
 693                 int argc = 0;
 694                 const char **argv2;
 695                 while (argv[argc]) argc++;
 696                 argv2 = xmalloc(sizeof(*argv) * (argc+1));
 697                 argv2[0] = (char *)cmd; /* full path to the script file */
 698                 memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
 699                 pid = mingw_spawnve(prog, argv2, env, 1);
 700                 if (pid >= 0) {
 701                         int status;
 702                         if (waitpid(pid, &status, 0) < 0)
 703                                 status = 255;
 704                         exit(status);
 705                 }
 706                 pid = 1;        /* indicate that we tried but failed */
 707                 free(prog);
 708                 free(argv2);
 709         }
 710         free_path_split(path);
 711         return pid;
 712 }
 713
 714 static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
 715 {
 716         /* check if git_command is a shell script */
 717         if (!try_shell_exec(cmd, argv, (char **)env)) {
 718                 int pid, status;
 719
 720                 pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
 721                 if (pid < 0)
 722                         return;
 723                 if (waitpid(pid, &status, 0) < 0)
 724                         status = 255;
 725                 exit(status);
 726         }
 727 }
 728
 729 void mingw_execvp(const char *cmd, char *const *argv)
 730 {
 731         char **path = get_path_split();
 732         char *prog = path_lookup(cmd, path, 0);
 733
 734         if (prog) {
 735                 mingw_execve(prog, argv, environ);
 736                 free(prog);
 737         } else
 738                 errno = ENOENT;
 739
 740         free_path_split(path);
 741 }
 742
 743 char **copy_environ()
 744 {
 745         char **env;
 746         int i = 0;
 747         while (environ[i])
 748                 i++;
 749         env = xmalloc((i+1)*sizeof(*env));
 750         for (i = 0; environ[i]; i++)
 751                 env[i] = xstrdup(environ[i]);
 752         env[i] = NULL;
 753         return env;
 754 }
 755
 756 void free_environ(char **env)
 757 {
 758         int i;
 759         for (i = 0; env[i]; i++)
 760                 free(env[i]);
 761         free(env);
 762 }
 763
 764 static int lookup_env(char **env, const char *name, size_t nmln)
 765 {
 766         int i;
 767
 768         for (i = 0; env[i]; i++) {
 769                 if (0 == strncmp(env[i], name, nmln)
 770                     && '=' == env[i][nmln])
 771                         /* matches */
 772                         return i;
 773         }
 774         return -1;
 775 }
 776
 777 /*
 778  * If name contains '=', then sets the variable, otherwise it unsets it
 779  */
 780 char **env_setenv(char **env, const char *name)
 781 {
 782         char *eq = strchrnul(name, '=');
 783         int i = lookup_env(env, name, eq-name);
 784
 785         if (i < 0) {
 786                 if (*eq) {
 787                         for (i = 0; env[i]; i++)
 788                                 ;
 789                         env = xrealloc(env, (i+2)*sizeof(*env));
 790                         env[i] = xstrdup(name);
 791                         env[i+1] = NULL;
 792                 }
 793         }
 794         else {
 795                 free(env[i]);
 796                 if (*eq)
 797                         env[i] = xstrdup(name);
 798                 else
 799                         for (; env[i]; i++)
 800                                 env[i] = env[i+1];
 801         }
 802         return env;
 803 }
 804
 805 /* this is the first function to call into WS_32; initialize it */
 806 #undef gethostbyname
 807 struct hostent *mingw_gethostbyname(const char *host)
 808 {
 809         WSADATA wsa;
 810
 811         if (WSAStartup(MAKEWORD(2,2), &wsa))
 812                 die("unable to initialize winsock subsystem, error %d",
 813                         WSAGetLastError());
 814         atexit((void(*)(void)) WSACleanup);
 815         return gethostbyname(host);
 816 }
 817
 818 int mingw_socket(int domain, int type, int protocol)
 819 {
 820         int sockfd;
 821         SOCKET s = WSASocket(domain, type, protocol, NULL, 0, 0);
 822         if (s == INVALID_SOCKET) {
 823                 /*
 824                  * WSAGetLastError() values are regular BSD error codes
 825                  * biased by WSABASEERR.
 826                  * However, strerror() does not know about networking
 827                  * specific errors, which are values beginning at 38 or so.
 828                  * Therefore, we choose to leave the biased error code
 829                  * in errno so that _if_ someone looks up the code somewhere,
 830                  * then it is at least the number that are usually listed.
 831                  */
 832                 errno = WSAGetLastError();
 833                 return -1;
 834         }
 835         /* convert into a file descriptor */
 836         if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
 837                 closesocket(s);
 838                 return error("unable to make a socket file descriptor: %s",
 839                         strerror(errno));
 840         }
 841         return sockfd;
 842 }
 843
 844 #undef connect
 845 int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
 846 {
 847         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
 848         return connect(s, sa, sz);
 849 }
 850
 851 #undef rename
 852 int mingw_rename(const char *pold, const char *pnew)
 853 {
 854         /*
 855          * Try native rename() first to get errno right.
 856          * It is based on MoveFile(), which cannot overwrite existing files.
 857          */
 858         if (!rename(pold, pnew))
 859                 return 0;
 860         if (errno != EEXIST)
 861                 return -1;
 862         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
 863                 return 0;
 864         /* TODO: translate more errors */
 865         if (GetLastError() == ERROR_ACCESS_DENIED) {
 866                 DWORD attrs = GetFileAttributes(pnew);
 867                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY)) {
 868                         errno = EISDIR;
 869                         return -1;
 870                 }
 871         }
 872         errno = EACCES;
 873         return -1;
 874 }
 875
 876 struct passwd *getpwuid(int uid)
 877 {
 878         static char user_name[100];
 879         static struct passwd p;
 880
 881         DWORD len = sizeof(user_name);
 882         if (!GetUserName(user_name, &len))
 883                 return NULL;
 884         p.pw_name = user_name;
 885         p.pw_gecos = "unknown";
 886         p.pw_dir = NULL;
 887         return &p;
 888 }
 889
 890 static HANDLE timer_event;
 891 static HANDLE timer_thread;
 892 static int timer_interval;
 893 static int one_shot;
 894 static sig_handler_t timer_fn = SIG_DFL;
 895
 896 /* The timer works like this:
 897  * The thread, ticktack(), is basically a trivial routine that most of the
 898  * time only waits to receive the signal to terminate. The main thread
 899  * tells the thread to terminate by setting the timer_event to the signalled
 900  * state.
 901  * But ticktack() does not wait indefinitely; instead, it interrupts the
 902  * wait state every now and then, namely exactly after timer's interval
 903  * length. At these opportunities it calls the signal handler.
 904  */
 905
 906 static __stdcall unsigned ticktack(void *dummy)
 907 {
 908         while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
 909                 if (timer_fn == SIG_DFL)
 910                         die("Alarm");
 911                 if (timer_fn != SIG_IGN)
 912                         timer_fn(SIGALRM);
 913                 if (one_shot)
 914                         break;
 915         }
 916         return 0;
 917 }
 918
 919 static int start_timer_thread(void)
 920 {
 921         timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 922         if (timer_event) {
 923                 timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
 924                 if (!timer_thread )
 925                         return errno = ENOMEM,
 926                                 error("cannot start timer thread");
 927         } else
 928                 return errno = ENOMEM,
 929                         error("cannot allocate resources timer");
 930         return 0;
 931 }
 932
 933 static void stop_timer_thread(void)
 934 {
 935         if (timer_event)
 936                 SetEvent(timer_event);  /* tell thread to terminate */
 937         if (timer_thread) {
 938                 int rc = WaitForSingleObject(timer_thread, 1000);
 939                 if (rc == WAIT_TIMEOUT)
 940                         error("timer thread did not terminate timely");
 941                 else if (rc != WAIT_OBJECT_0)
 942                         error("waiting for timer thread failed: %lu",
 943                               GetLastError());
 944                 CloseHandle(timer_thread);
 945         }
 946         if (timer_event)
 947                 CloseHandle(timer_event);
 948         timer_event = NULL;
 949         timer_thread = NULL;
 950 }
 951
 952 static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
 953 {
 954         return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
 955 }
 956
 957 int setitimer(int type, struct itimerval *in, struct itimerval *out)
 958 {
 959         static const struct timeval zero;
 960         static int atexit_done;
 961
 962         if (out != NULL)
 963                 return errno = EINVAL,
 964                         error("setitmer param 3 != NULL not implemented");
 965         if (!is_timeval_eq(&in->it_interval, &zero) &&
 966             !is_timeval_eq(&in->it_interval, &in->it_value))
 967                 return errno = EINVAL,
 968                         error("setitmer: it_interval must be zero or eq it_value");
 969
 970         if (timer_thread)
 971                 stop_timer_thread();
 972
 973         if (is_timeval_eq(&in->it_value, &zero) &&
 974             is_timeval_eq(&in->it_interval, &zero))
 975                 return 0;
 976
 977         timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
 978         one_shot = is_timeval_eq(&in->it_interval, &zero);
 979         if (!atexit_done) {
 980                 atexit(stop_timer_thread);
 981                 atexit_done = 1;
 982         }
 983         return start_timer_thread();
 984 }
 985
 986 int sigaction(int sig, struct sigaction *in, struct sigaction *out)
 987 {
 988         if (sig != SIGALRM)
 989                 return errno = EINVAL,
 990                         error("sigaction only implemented for SIGALRM");
 991         if (out != NULL)
 992                 return errno = EINVAL,
 993                         error("sigaction: param 3 != NULL not implemented");
 994
 995         timer_fn = in->sa_handler;
 996         return 0;
 997 }
 998
 999 #undef signal
1000 sig_handler_t mingw_signal(int sig, sig_handler_t handler)
1001 {
1002         if (sig != SIGALRM)
1003                 return signal(sig, handler);
1004         sig_handler_t old = timer_fn;
1005         timer_fn = handler;
1006         return old;
1007 }