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         extern time_t my_mktime(struct tm *tm);
 222         SYSTEMTIME st;
 223         struct tm tm;
 224         GetSystemTime(&st);
 225         tm.tm_year = st.wYear-1900;
 226         tm.tm_mon = st.wMonth-1;
 227         tm.tm_mday = st.wDay;
 228         tm.tm_hour = st.wHour;
 229         tm.tm_min = st.wMinute;
 230         tm.tm_sec = st.wSecond;
 231         tv->tv_sec = my_mktime(&tm);
 232         if (tv->tv_sec < 0)
 233                 return -1;
 234         tv->tv_usec = st.wMilliseconds*1000;
 235         return 0;
 236 }
 237
 238 int pipe(int filedes[2])
 239 {
 240         int fd;
 241         HANDLE h[2], parent;
 242
 243         if (_pipe(filedes, 8192, 0) < 0)
 244                 return -1;
 245
 246         parent = GetCurrentProcess();
 247
 248         if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[0]),
 249                         parent, &h[0], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
 250                 close(filedes[0]);
 251                 close(filedes[1]);
 252                 return -1;
 253         }
 254         if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[1]),
 255                         parent, &h[1], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
 256                 close(filedes[0]);
 257                 close(filedes[1]);
 258                 CloseHandle(h[0]);
 259                 return -1;
 260         }
 261         fd = _open_osfhandle((int)h[0], O_NOINHERIT);
 262         if (fd < 0) {
 263                 close(filedes[0]);
 264                 close(filedes[1]);
 265                 CloseHandle(h[0]);
 266                 CloseHandle(h[1]);
 267                 return -1;
 268         }
 269         close(filedes[0]);
 270         filedes[0] = fd;
 271         fd = _open_osfhandle((int)h[1], O_NOINHERIT);
 272         if (fd < 0) {
 273                 close(filedes[0]);
 274                 close(filedes[1]);
 275                 CloseHandle(h[1]);
 276                 return -1;
 277         }
 278         close(filedes[1]);
 279         filedes[1] = fd;
 280         return 0;
 281 }
 282
 283 int poll(struct pollfd *ufds, unsigned int nfds, int timeout)
 284 {
 285         int i, pending;
 286
 287         if (timeout != -1)
 288                 return errno = EINVAL, error("poll timeout not supported");
 289
 290         /* When there is only one fd to wait for, then we pretend that
 291          * input is available and let the actual wait happen when the
 292          * caller invokes read().
 293          */
 294         if (nfds == 1) {
 295                 if (!(ufds[0].events & POLLIN))
 296                         return errno = EINVAL, error("POLLIN not set");
 297                 ufds[0].revents = POLLIN;
 298                 return 0;
 299         }
 300
 301 repeat:
 302         pending = 0;
 303         for (i = 0; i < nfds; i++) {
 304                 DWORD avail = 0;
 305                 HANDLE h = (HANDLE) _get_osfhandle(ufds[i].fd);
 306                 if (h == INVALID_HANDLE_VALUE)
 307                         return -1;      /* errno was set */
 308
 309                 if (!(ufds[i].events & POLLIN))
 310                         return errno = EINVAL, error("POLLIN not set");
 311
 312                 /* this emulation works only for pipes */
 313                 if (!PeekNamedPipe(h, NULL, 0, NULL, &avail, NULL)) {
 314                         int err = GetLastError();
 315                         if (err == ERROR_BROKEN_PIPE) {
 316                                 ufds[i].revents = POLLHUP;
 317                                 pending++;
 318                         } else {
 319                                 errno = EINVAL;
 320                                 return error("PeekNamedPipe failed,"
 321                                         " GetLastError: %u", err);
 322                         }
 323                 } else if (avail) {
 324                         ufds[i].revents = POLLIN;
 325                         pending++;
 326                 } else
 327                         ufds[i].revents = 0;
 328         }
 329         if (!pending) {
 330                 /* The only times that we spin here is when the process
 331                  * that is connected through the pipes is waiting for
 332                  * its own input data to become available. But since
 333                  * the process (pack-objects) is itself CPU intensive,
 334                  * it will happily pick up the time slice that we are
 335                  * relinguishing here.
 336                  */
 337                 Sleep(0);
 338                 goto repeat;
 339         }
 340         return 0;
 341 }
 342
 343 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 344 {
 345         /* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 346         memcpy(result, gmtime(timep), sizeof(struct tm));
 347         return result;
 348 }
 349
 350 struct tm *localtime_r(const time_t *timep, struct tm *result)
 351 {
 352         /* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 353         memcpy(result, localtime(timep), sizeof(struct tm));
 354         return result;
 355 }
 356
 357 #undef getcwd
 358 char *mingw_getcwd(char *pointer, int len)
 359 {
 360         int i;
 361         char *ret = getcwd(pointer, len);
 362         if (!ret)
 363                 return ret;
 364         for (i = 0; pointer[i]; i++)
 365                 if (pointer[i] == '\\')
 366                         pointer[i] = '/';
 367         return ret;
 368 }
 369
 370 /*
 371  * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
 372  * (Parsing C++ Command-Line Arguments)
 373  */
 374 static const char *quote_arg(const char *arg)
 375 {
 376         /* count chars to quote */
 377         int len = 0, n = 0;
 378         int force_quotes = 0;
 379         char *q, *d;
 380         const char *p = arg;
 381         if (!*p) force_quotes = 1;
 382         while (*p) {
 383                 if (isspace(*p) || *p == '*' || *p == '?')
 384                         force_quotes = 1;
 385                 else if (*p == '"')
 386                         n++;
 387                 else if (*p == '\\') {
 388                         int count = 0;
 389                         while (*p == '\\') {
 390                                 count++;
 391                                 p++;
 392                                 len++;
 393                         }
 394                         if (*p == '"')
 395                                 n += count*2 + 1;
 396                         continue;
 397                 }
 398                 len++;
 399                 p++;
 400         }
 401         if (!force_quotes && n == 0)
 402                 return arg;
 403
 404         /* insert \ where necessary */
 405         d = q = xmalloc(len+n+3);
 406         *d++ = '"';
 407         while (*arg) {
 408                 if (*arg == '"')
 409                         *d++ = '\\';
 410                 else if (*arg == '\\') {
 411                         int count = 0;
 412                         while (*arg == '\\') {
 413                                 count++;
 414                                 *d++ = *arg++;
 415                         }
 416                         if (*arg == '"') {
 417                                 while (count-- > 0)
 418                                         *d++ = '\\';
 419                                 *d++ = '\\';
 420                         }
 421                 }
 422                 *d++ = *arg++;
 423         }
 424         *d++ = '"';
 425         *d++ = 0;
 426         return q;
 427 }
 428
 429 static const char *parse_interpreter(const char *cmd)
 430 {
 431         static char buf[100];
 432         char *p, *opt;
 433         int n, fd;
 434
 435         /* don't even try a .exe */
 436         n = strlen(cmd);
 437         if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
 438                 return NULL;
 439
 440         fd = open(cmd, O_RDONLY);
 441         if (fd < 0)
 442                 return NULL;
 443         n = read(fd, buf, sizeof(buf)-1);
 444         close(fd);
 445         if (n < 4)      /* at least '#!/x' and not error */
 446                 return NULL;
 447
 448         if (buf[0] != '#' || buf[1] != '!')
 449                 return NULL;
 450         buf[n] = '\0';
 451         p = strchr(buf, '\n');
 452         if (!p)
 453                 return NULL;
 454
 455         *p = '\0';
 456         if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
 457                 return NULL;
 458         /* strip options */
 459         if ((opt = strchr(p+1, ' ')))
 460                 *opt = '\0';
 461         return p+1;
 462 }
 463
 464 /*
 465  * Splits the PATH into parts.
 466  */
 467 static char **get_path_split(void)
 468 {
 469         char *p, **path, *envpath = getenv("PATH");
 470         int i, n = 0;
 471
 472         if (!envpath || !*envpath)
 473                 return NULL;
 474
 475         envpath = xstrdup(envpath);
 476         p = envpath;
 477         while (p) {
 478                 char *dir = p;
 479                 p = strchr(p, ';');
 480                 if (p) *p++ = '\0';
 481                 if (*dir) {     /* not earlier, catches series of ; */
 482                         ++n;
 483                 }
 484         }
 485         if (!n)
 486                 return NULL;
 487
 488         path = xmalloc((n+1)*sizeof(char*));
 489         p = envpath;
 490         i = 0;
 491         do {
 492                 if (*p)
 493                         path[i++] = xstrdup(p);
 494                 p = p+strlen(p)+1;
 495         } while (i < n);
 496         path[i] = NULL;
 497
 498         free(envpath);
 499
 500         return path;
 501 }
 502
 503 static void free_path_split(char **path)
 504 {
 505         if (!path)
 506                 return;
 507
 508         char **p = path;
 509         while (*p)
 510                 free(*p++);
 511         free(path);
 512 }
 513
 514 /*
 515  * exe_only means that we only want to detect .exe files, but not scripts
 516  * (which do not have an extension)
 517  */
 518 static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
 519 {
 520         char path[MAX_PATH];
 521         snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
 522
 523         if (!isexe && access(path, F_OK) == 0)
 524                 return xstrdup(path);
 525         path[strlen(path)-4] = '\0';
 526         if ((!exe_only || isexe) && access(path, F_OK) == 0)
 527                 return xstrdup(path);
 528         return NULL;
 529 }
 530
 531 /*
 532  * Determines the absolute path of cmd using the the split path in path.
 533  * If cmd contains a slash or backslash, no lookup is performed.
 534  */
 535 static char *path_lookup(const char *cmd, char **path, int exe_only)
 536 {
 537         char *prog = NULL;
 538         int len = strlen(cmd);
 539         int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 540
 541         if (strchr(cmd, '/') || strchr(cmd, '\\'))
 542                 prog = xstrdup(cmd);
 543
 544         while (!prog && *path)
 545                 prog = lookup_prog(*path++, cmd, isexe, exe_only);
 546
 547         return prog;
 548 }
 549
 550 static int env_compare(const void *a, const void *b)
 551 {
 552         char *const *ea = a;
 553         char *const *eb = b;
 554         return strcasecmp(*ea, *eb);
 555 }
 556
 557 static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
 558                            int prepend_cmd)
 559 {
 560         STARTUPINFO si;
 561         PROCESS_INFORMATION pi;
 562         struct strbuf envblk, args;
 563         unsigned flags;
 564         BOOL ret;
 565
 566         /* Determine whether or not we are associated to a console */
 567         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
 568                         FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 569                         FILE_ATTRIBUTE_NORMAL, NULL);
 570         if (cons == INVALID_HANDLE_VALUE) {
 571                 /* There is no console associated with this process.
 572                  * Since the child is a console process, Windows
 573                  * would normally create a console window. But
 574                  * since we'll be redirecting std streams, we do
 575                  * not need the console.
 576                  */
 577                 flags = CREATE_NO_WINDOW;
 578         } else {
 579                 /* There is already a console. If we specified
 580                  * CREATE_NO_WINDOW here, too, Windows would
 581                  * disassociate the child from the console.
 582                  * Go figure!
 583                  */
 584                 flags = 0;
 585                 CloseHandle(cons);
 586         }
 587         memset(&si, 0, sizeof(si));
 588         si.cb = sizeof(si);
 589         si.dwFlags = STARTF_USESTDHANDLES;
 590         si.hStdInput = (HANDLE) _get_osfhandle(0);
 591         si.hStdOutput = (HANDLE) _get_osfhandle(1);
 592         si.hStdError = (HANDLE) _get_osfhandle(2);
 593
 594         /* concatenate argv, quoting args as we go */
 595         strbuf_init(&args, 0);
 596         if (prepend_cmd) {
 597                 char *quoted = (char *)quote_arg(cmd);
 598                 strbuf_addstr(&args, quoted);
 599                 if (quoted != cmd)
 600                         free(quoted);
 601         }
 602         for (; *argv; argv++) {
 603                 char *quoted = (char *)quote_arg(*argv);
 604                 if (*args.buf)
 605                         strbuf_addch(&args, ' ');
 606                 strbuf_addstr(&args, quoted);
 607                 if (quoted != *argv)
 608                         free(quoted);
 609         }
 610
 611         if (env) {
 612                 int count = 0;
 613                 char **e, **sorted_env;
 614
 615                 for (e = env; *e; e++)
 616                         count++;
 617
 618                 /* environment must be sorted */
 619                 sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
 620                 memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
 621                 qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
 622
 623                 strbuf_init(&envblk, 0);
 624                 for (e = sorted_env; *e; e++) {
 625                         strbuf_addstr(&envblk, *e);
 626                         strbuf_addch(&envblk, '\0');
 627                 }
 628                 free(sorted_env);
 629         }
 630
 631         memset(&pi, 0, sizeof(pi));
 632         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
 633                 env ? envblk.buf : NULL, NULL, &si, &pi);
 634
 635         if (env)
 636                 strbuf_release(&envblk);
 637         strbuf_release(&args);
 638
 639         if (!ret) {
 640                 errno = ENOENT;
 641                 return -1;
 642         }
 643         CloseHandle(pi.hThread);
 644         return (pid_t)pi.hProcess;
 645 }
 646
 647 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env)
 648 {
 649         pid_t pid;
 650         char **path = get_path_split();
 651         char *prog = path_lookup(cmd, path, 0);
 652
 653         if (!prog) {
 654                 errno = ENOENT;
 655                 pid = -1;
 656         }
 657         else {
 658                 const char *interpr = parse_interpreter(prog);
 659
 660                 if (interpr) {
 661                         const char *argv0 = argv[0];
 662                         char *iprog = path_lookup(interpr, path, 1);
 663                         argv[0] = prog;
 664                         if (!iprog) {
 665                                 errno = ENOENT;
 666                                 pid = -1;
 667                         }
 668                         else {
 669                                 pid = mingw_spawnve(iprog, argv, env, 1);
 670                                 free(iprog);
 671                         }
 672                         argv[0] = argv0;
 673                 }
 674                 else
 675                         pid = mingw_spawnve(prog, argv, env, 0);
 676                 free(prog);
 677         }
 678         free_path_split(path);
 679         return pid;
 680 }
 681
 682 static int try_shell_exec(const char *cmd, char *const *argv, char **env)
 683 {
 684         const char *interpr = parse_interpreter(cmd);
 685         char **path;
 686         char *prog;
 687         int pid = 0;
 688
 689         if (!interpr)
 690                 return 0;
 691         path = get_path_split();
 692         prog = path_lookup(interpr, path, 1);
 693         if (prog) {
 694                 int argc = 0;
 695                 const char **argv2;
 696                 while (argv[argc]) argc++;
 697                 argv2 = xmalloc(sizeof(*argv) * (argc+1));
 698                 argv2[0] = (char *)cmd; /* full path to the script file */
 699                 memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
 700                 pid = mingw_spawnve(prog, argv2, env, 1);
 701                 if (pid >= 0) {
 702                         int status;
 703                         if (waitpid(pid, &status, 0) < 0)
 704                                 status = 255;
 705                         exit(status);
 706                 }
 707                 pid = 1;        /* indicate that we tried but failed */
 708                 free(prog);
 709                 free(argv2);
 710         }
 711         free_path_split(path);
 712         return pid;
 713 }
 714
 715 static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
 716 {
 717         /* check if git_command is a shell script */
 718         if (!try_shell_exec(cmd, argv, (char **)env)) {
 719                 int pid, status;
 720
 721                 pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
 722                 if (pid < 0)
 723                         return;
 724                 if (waitpid(pid, &status, 0) < 0)
 725                         status = 255;
 726                 exit(status);
 727         }
 728 }
 729
 730 void mingw_execvp(const char *cmd, char *const *argv)
 731 {
 732         char **path = get_path_split();
 733         char *prog = path_lookup(cmd, path, 0);
 734
 735         if (prog) {
 736                 mingw_execve(prog, argv, environ);
 737                 free(prog);
 738         } else
 739                 errno = ENOENT;
 740
 741         free_path_split(path);
 742 }
 743
 744 char **copy_environ()
 745 {
 746         char **env;
 747         int i = 0;
 748         while (environ[i])
 749                 i++;
 750         env = xmalloc((i+1)*sizeof(*env));
 751         for (i = 0; environ[i]; i++)
 752                 env[i] = xstrdup(environ[i]);
 753         env[i] = NULL;
 754         return env;
 755 }
 756
 757 void free_environ(char **env)
 758 {
 759         int i;
 760         for (i = 0; env[i]; i++)
 761                 free(env[i]);
 762         free(env);
 763 }
 764
 765 static int lookup_env(char **env, const char *name, size_t nmln)
 766 {
 767         int i;
 768
 769         for (i = 0; env[i]; i++) {
 770                 if (0 == strncmp(env[i], name, nmln)
 771                     && '=' == env[i][nmln])
 772                         /* matches */
 773                         return i;
 774         }
 775         return -1;
 776 }
 777
 778 /*
 779  * If name contains '=', then sets the variable, otherwise it unsets it
 780  */
 781 char **env_setenv(char **env, const char *name)
 782 {
 783         char *eq = strchrnul(name, '=');
 784         int i = lookup_env(env, name, eq-name);
 785
 786         if (i < 0) {
 787                 if (*eq) {
 788                         for (i = 0; env[i]; i++)
 789                                 ;
 790                         env = xrealloc(env, (i+2)*sizeof(*env));
 791                         env[i] = xstrdup(name);
 792                         env[i+1] = NULL;
 793                 }
 794         }
 795         else {
 796                 free(env[i]);
 797                 if (*eq)
 798                         env[i] = xstrdup(name);
 799                 else
 800                         for (; env[i]; i++)
 801                                 env[i] = env[i+1];
 802         }
 803         return env;
 804 }
 805
 806 /* this is the first function to call into WS_32; initialize it */
 807 #undef gethostbyname
 808 struct hostent *mingw_gethostbyname(const char *host)
 809 {
 810         WSADATA wsa;
 811
 812         if (WSAStartup(MAKEWORD(2,2), &wsa))
 813                 die("unable to initialize winsock subsystem, error %d",
 814                         WSAGetLastError());
 815         atexit((void(*)(void)) WSACleanup);
 816         return gethostbyname(host);
 817 }
 818
 819 int mingw_socket(int domain, int type, int protocol)
 820 {
 821         int sockfd;
 822         SOCKET s = WSASocket(domain, type, protocol, NULL, 0, 0);
 823         if (s == INVALID_SOCKET) {
 824                 /*
 825                  * WSAGetLastError() values are regular BSD error codes
 826                  * biased by WSABASEERR.
 827                  * However, strerror() does not know about networking
 828                  * specific errors, which are values beginning at 38 or so.
 829                  * Therefore, we choose to leave the biased error code
 830                  * in errno so that _if_ someone looks up the code somewhere,
 831                  * then it is at least the number that are usually listed.
 832                  */
 833                 errno = WSAGetLastError();
 834                 return -1;
 835         }
 836         /* convert into a file descriptor */
 837         if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
 838                 closesocket(s);
 839                 return error("unable to make a socket file descriptor: %s",
 840                         strerror(errno));
 841         }
 842         return sockfd;
 843 }
 844
 845 #undef connect
 846 int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
 847 {
 848         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
 849         return connect(s, sa, sz);
 850 }
 851
 852 #undef rename
 853 int mingw_rename(const char *pold, const char *pnew)
 854 {
 855         /*
 856          * Try native rename() first to get errno right.
 857          * It is based on MoveFile(), which cannot overwrite existing files.
 858          */
 859         if (!rename(pold, pnew))
 860                 return 0;
 861         if (errno != EEXIST)
 862                 return -1;
 863         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
 864                 return 0;
 865         /* TODO: translate more errors */
 866         if (GetLastError() == ERROR_ACCESS_DENIED) {
 867                 DWORD attrs = GetFileAttributes(pnew);
 868                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY)) {
 869                         errno = EISDIR;
 870                         return -1;
 871                 }
 872         }
 873         errno = EACCES;
 874         return -1;
 875 }
 876
 877 struct passwd *getpwuid(int uid)
 878 {
 879         static char user_name[100];
 880         static struct passwd p;
 881
 882         DWORD len = sizeof(user_name);
 883         if (!GetUserName(user_name, &len))
 884                 return NULL;
 885         p.pw_name = user_name;
 886         p.pw_gecos = "unknown";
 887         p.pw_dir = NULL;
 888         return &p;
 889 }
 890
 891 static HANDLE timer_event;
 892 static HANDLE timer_thread;
 893 static int timer_interval;
 894 static int one_shot;
 895 static sig_handler_t timer_fn = SIG_DFL;
 896
 897 /* The timer works like this:
 898  * The thread, ticktack(), is basically a trivial routine that most of the
 899  * time only waits to receive the signal to terminate. The main thread
 900  * tells the thread to terminate by setting the timer_event to the signalled
 901  * state.
 902  * But ticktack() does not wait indefinitely; instead, it interrupts the
 903  * wait state every now and then, namely exactly after timer's interval
 904  * length. At these opportunities it calls the signal handler.
 905  */
 906
 907 static __stdcall unsigned ticktack(void *dummy)
 908 {
 909         while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
 910                 if (timer_fn == SIG_DFL)
 911                         die("Alarm");
 912                 if (timer_fn != SIG_IGN)
 913                         timer_fn(SIGALRM);
 914                 if (one_shot)
 915                         break;
 916         }
 917         return 0;
 918 }
 919
 920 static int start_timer_thread(void)
 921 {
 922         timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 923         if (timer_event) {
 924                 timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
 925                 if (!timer_thread )
 926                         return errno = ENOMEM,
 927                                 error("cannot start timer thread");
 928         } else
 929                 return errno = ENOMEM,
 930                         error("cannot allocate resources timer");
 931         return 0;
 932 }
 933
 934 static void stop_timer_thread(void)
 935 {
 936         if (timer_event)
 937                 SetEvent(timer_event);  /* tell thread to terminate */
 938         if (timer_thread) {
 939                 int rc = WaitForSingleObject(timer_thread, 1000);
 940                 if (rc == WAIT_TIMEOUT)
 941                         error("timer thread did not terminate timely");
 942                 else if (rc != WAIT_OBJECT_0)
 943                         error("waiting for timer thread failed: %lu",
 944                               GetLastError());
 945                 CloseHandle(timer_thread);
 946         }
 947         if (timer_event)
 948                 CloseHandle(timer_event);
 949         timer_event = NULL;
 950         timer_thread = NULL;
 951 }
 952
 953 static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
 954 {
 955         return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
 956 }
 957
 958 int setitimer(int type, struct itimerval *in, struct itimerval *out)
 959 {
 960         static const struct timeval zero;
 961         static int atexit_done;
 962
 963         if (out != NULL)
 964                 return errno = EINVAL,
 965                         error("setitmer param 3 != NULL not implemented");
 966         if (!is_timeval_eq(&in->it_interval, &zero) &&
 967             !is_timeval_eq(&in->it_interval, &in->it_value))
 968                 return errno = EINVAL,
 969                         error("setitmer: it_interval must be zero or eq it_value");
 970
 971         if (timer_thread)
 972                 stop_timer_thread();
 973
 974         if (is_timeval_eq(&in->it_value, &zero) &&
 975             is_timeval_eq(&in->it_interval, &zero))
 976                 return 0;
 977
 978         timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
 979         one_shot = is_timeval_eq(&in->it_interval, &zero);
 980         if (!atexit_done) {
 981                 atexit(stop_timer_thread);
 982                 atexit_done = 1;
 983         }
 984         return start_timer_thread();
 985 }
 986
 987 int sigaction(int sig, struct sigaction *in, struct sigaction *out)
 988 {
 989         if (sig != SIGALRM)
 990                 return errno = EINVAL,
 991                         error("sigaction only implemented for SIGALRM");
 992         if (out != NULL)
 993                 return errno = EINVAL,
 994                         error("sigaction: param 3 != NULL not implemented");
 995
 996         timer_fn = in->sa_handler;
 997         return 0;
 998 }
 999
1000 #undef signal
1001 sig_handler_t mingw_signal(int sig, sig_handler_t handler)
1002 {
1003         if (sig != SIGALRM)
1004                 return signal(sig, handler);
1005         sig_handler_t old = timer_fn;
1006         timer_fn = handler;
1007         return old;
1008 }