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 != -1)
 267                 return errno = EINVAL, error("poll timeout not supported");
 268
 269         /* When there is only one fd to wait for, then we pretend that
 270          * input is available and let the actual wait happen when the
 271          * caller invokes read().
 272          */
 273         if (nfds == 1) {
 274                 if (!(ufds[0].events & POLLIN))
 275                         return errno = EINVAL, error("POLLIN not set");
 276                 ufds[0].revents = POLLIN;
 277                 return 0;
 278         }
 279
 280 repeat:
 281         pending = 0;
 282         for (i = 0; i < nfds; i++) {
 283                 DWORD avail = 0;
 284                 HANDLE h = (HANDLE) _get_osfhandle(ufds[i].fd);
 285                 if (h == INVALID_HANDLE_VALUE)
 286                         return -1;      /* errno was set */
 287
 288                 if (!(ufds[i].events & POLLIN))
 289                         return errno = EINVAL, error("POLLIN not set");
 290
 291                 /* this emulation works only for pipes */
 292                 if (!PeekNamedPipe(h, NULL, 0, NULL, &avail, NULL)) {
 293                         int err = GetLastError();
 294                         if (err == ERROR_BROKEN_PIPE) {
 295                                 ufds[i].revents = POLLHUP;
 296                                 pending++;
 297                         } else {
 298                                 errno = EINVAL;
 299                                 return error("PeekNamedPipe failed,"
 300                                         " GetLastError: %u", err);
 301                         }
 302                 } else if (avail) {
 303                         ufds[i].revents = POLLIN;
 304                         pending++;
 305                 } else
 306                         ufds[i].revents = 0;
 307         }
 308         if (!pending) {
 309                 /* The only times that we spin here is when the process
 310                  * that is connected through the pipes is waiting for
 311                  * its own input data to become available. But since
 312                  * the process (pack-objects) is itself CPU intensive,
 313                  * it will happily pick up the time slice that we are
 314                  * relinguishing here.
 315                  */
 316                 Sleep(0);
 317                 goto repeat;
 318         }
 319         return 0;
 320 }
 321
 322 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 323 {
 324         /* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 325         memcpy(result, gmtime(timep), sizeof(struct tm));
 326         return result;
 327 }
 328
 329 struct tm *localtime_r(const time_t *timep, struct tm *result)
 330 {
 331         /* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 332         memcpy(result, localtime(timep), sizeof(struct tm));
 333         return result;
 334 }
 335
 336 #undef getcwd
 337 char *mingw_getcwd(char *pointer, int len)
 338 {
 339         int i;
 340         char *ret = getcwd(pointer, len);
 341         if (!ret)
 342                 return ret;
 343         for (i = 0; pointer[i]; i++)
 344                 if (pointer[i] == '\\')
 345                         pointer[i] = '/';
 346         return ret;
 347 }
 348
 349 #undef getenv
 350 char *mingw_getenv(const char *name)
 351 {
 352         char *result = getenv(name);
 353         if (!result && !strcmp(name, "TMPDIR")) {
 354                 /* on Windows it is TMP and TEMP */
 355                 result = getenv("TMP");
 356                 if (!result)
 357                         result = getenv("TEMP");
 358         }
 359         return result;
 360 }
 361
 362 /*
 363  * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
 364  * (Parsing C++ Command-Line Arguments)
 365  */
 366 static const char *quote_arg(const char *arg)
 367 {
 368         /* count chars to quote */
 369         int len = 0, n = 0;
 370         int force_quotes = 0;
 371         char *q, *d;
 372         const char *p = arg;
 373         if (!*p) force_quotes = 1;
 374         while (*p) {
 375                 if (isspace(*p) || *p == '*' || *p == '?' || *p == '{')
 376                         force_quotes = 1;
 377                 else if (*p == '"')
 378                         n++;
 379                 else if (*p == '\\') {
 380                         int count = 0;
 381                         while (*p == '\\') {
 382                                 count++;
 383                                 p++;
 384                                 len++;
 385                         }
 386                         if (*p == '"')
 387                                 n += count*2 + 1;
 388                         continue;
 389                 }
 390                 len++;
 391                 p++;
 392         }
 393         if (!force_quotes && n == 0)
 394                 return arg;
 395
 396         /* insert \ where necessary */
 397         d = q = xmalloc(len+n+3);
 398         *d++ = '"';
 399         while (*arg) {
 400                 if (*arg == '"')
 401                         *d++ = '\\';
 402                 else if (*arg == '\\') {
 403                         int count = 0;
 404                         while (*arg == '\\') {
 405                                 count++;
 406                                 *d++ = *arg++;
 407                         }
 408                         if (*arg == '"') {
 409                                 while (count-- > 0)
 410                                         *d++ = '\\';
 411                                 *d++ = '\\';
 412                         }
 413                 }
 414                 *d++ = *arg++;
 415         }
 416         *d++ = '"';
 417         *d++ = 0;
 418         return q;
 419 }
 420
 421 static const char *parse_interpreter(const char *cmd)
 422 {
 423         static char buf[100];
 424         char *p, *opt;
 425         int n, fd;
 426
 427         /* don't even try a .exe */
 428         n = strlen(cmd);
 429         if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
 430                 return NULL;
 431
 432         fd = open(cmd, O_RDONLY);
 433         if (fd < 0)
 434                 return NULL;
 435         n = read(fd, buf, sizeof(buf)-1);
 436         close(fd);
 437         if (n < 4)      /* at least '#!/x' and not error */
 438                 return NULL;
 439
 440         if (buf[0] != '#' || buf[1] != '!')
 441                 return NULL;
 442         buf[n] = '\0';
 443         p = strchr(buf, '\n');
 444         if (!p)
 445                 return NULL;
 446
 447         *p = '\0';
 448         if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
 449                 return NULL;
 450         /* strip options */
 451         if ((opt = strchr(p+1, ' ')))
 452                 *opt = '\0';
 453         return p+1;
 454 }
 455
 456 /*
 457  * Splits the PATH into parts.
 458  */
 459 static char **get_path_split(void)
 460 {
 461         char *p, **path, *envpath = getenv("PATH");
 462         int i, n = 0;
 463
 464         if (!envpath || !*envpath)
 465                 return NULL;
 466
 467         envpath = xstrdup(envpath);
 468         p = envpath;
 469         while (p) {
 470                 char *dir = p;
 471                 p = strchr(p, ';');
 472                 if (p) *p++ = '\0';
 473                 if (*dir) {     /* not earlier, catches series of ; */
 474                         ++n;
 475                 }
 476         }
 477         if (!n)
 478                 return NULL;
 479
 480         path = xmalloc((n+1)*sizeof(char*));
 481         p = envpath;
 482         i = 0;
 483         do {
 484                 if (*p)
 485                         path[i++] = xstrdup(p);
 486                 p = p+strlen(p)+1;
 487         } while (i < n);
 488         path[i] = NULL;
 489
 490         free(envpath);
 491
 492         return path;
 493 }
 494
 495 static void free_path_split(char **path)
 496 {
 497         if (!path)
 498                 return;
 499
 500         char **p = path;
 501         while (*p)
 502                 free(*p++);
 503         free(path);
 504 }
 505
 506 /*
 507  * exe_only means that we only want to detect .exe files, but not scripts
 508  * (which do not have an extension)
 509  */
 510 static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
 511 {
 512         char path[MAX_PATH];
 513         snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
 514
 515         if (!isexe && access(path, F_OK) == 0)
 516                 return xstrdup(path);
 517         path[strlen(path)-4] = '\0';
 518         if ((!exe_only || isexe) && access(path, F_OK) == 0)
 519                 if (!(GetFileAttributes(path) & FILE_ATTRIBUTE_DIRECTORY))
 520                         return xstrdup(path);
 521         return NULL;
 522 }
 523
 524 /*
 525  * Determines the absolute path of cmd using the the split path in path.
 526  * If cmd contains a slash or backslash, no lookup is performed.
 527  */
 528 static char *path_lookup(const char *cmd, char **path, int exe_only)
 529 {
 530         char *prog = NULL;
 531         int len = strlen(cmd);
 532         int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 533
 534         if (strchr(cmd, '/') || strchr(cmd, '\\'))
 535                 prog = xstrdup(cmd);
 536
 537         while (!prog && *path)
 538                 prog = lookup_prog(*path++, cmd, isexe, exe_only);
 539
 540         return prog;
 541 }
 542
 543 static int env_compare(const void *a, const void *b)
 544 {
 545         char *const *ea = a;
 546         char *const *eb = b;
 547         return strcasecmp(*ea, *eb);
 548 }
 549
 550 static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
 551                            int prepend_cmd)
 552 {
 553         STARTUPINFO si;
 554         PROCESS_INFORMATION pi;
 555         struct strbuf envblk, args;
 556         unsigned flags;
 557         BOOL ret;
 558
 559         /* Determine whether or not we are associated to a console */
 560         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
 561                         FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 562                         FILE_ATTRIBUTE_NORMAL, NULL);
 563         if (cons == INVALID_HANDLE_VALUE) {
 564                 /* There is no console associated with this process.
 565                  * Since the child is a console process, Windows
 566                  * would normally create a console window. But
 567                  * since we'll be redirecting std streams, we do
 568                  * not need the console.
 569                  */
 570                 flags = CREATE_NO_WINDOW;
 571         } else {
 572                 /* There is already a console. If we specified
 573                  * CREATE_NO_WINDOW here, too, Windows would
 574                  * disassociate the child from the console.
 575                  * Go figure!
 576                  */
 577                 flags = 0;
 578                 CloseHandle(cons);
 579         }
 580         memset(&si, 0, sizeof(si));
 581         si.cb = sizeof(si);
 582         si.dwFlags = STARTF_USESTDHANDLES;
 583         si.hStdInput = (HANDLE) _get_osfhandle(0);
 584         si.hStdOutput = (HANDLE) _get_osfhandle(1);
 585         si.hStdError = (HANDLE) _get_osfhandle(2);
 586
 587         /* concatenate argv, quoting args as we go */
 588         strbuf_init(&args, 0);
 589         if (prepend_cmd) {
 590                 char *quoted = (char *)quote_arg(cmd);
 591                 strbuf_addstr(&args, quoted);
 592                 if (quoted != cmd)
 593                         free(quoted);
 594         }
 595         for (; *argv; argv++) {
 596                 char *quoted = (char *)quote_arg(*argv);
 597                 if (*args.buf)
 598                         strbuf_addch(&args, ' ');
 599                 strbuf_addstr(&args, quoted);
 600                 if (quoted != *argv)
 601                         free(quoted);
 602         }
 603
 604         if (env) {
 605                 int count = 0;
 606                 char **e, **sorted_env;
 607
 608                 for (e = env; *e; e++)
 609                         count++;
 610
 611                 /* environment must be sorted */
 612                 sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
 613                 memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
 614                 qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
 615
 616                 strbuf_init(&envblk, 0);
 617                 for (e = sorted_env; *e; e++) {
 618                         strbuf_addstr(&envblk, *e);
 619                         strbuf_addch(&envblk, '\0');
 620                 }
 621                 free(sorted_env);
 622         }
 623
 624         memset(&pi, 0, sizeof(pi));
 625         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
 626                 env ? envblk.buf : NULL, NULL, &si, &pi);
 627
 628         if (env)
 629                 strbuf_release(&envblk);
 630         strbuf_release(&args);
 631
 632         if (!ret) {
 633                 errno = ENOENT;
 634                 return -1;
 635         }
 636         CloseHandle(pi.hThread);
 637         return (pid_t)pi.hProcess;
 638 }
 639
 640 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env)
 641 {
 642         pid_t pid;
 643         char **path = get_path_split();
 644         char *prog = path_lookup(cmd, path, 0);
 645
 646         if (!prog) {
 647                 errno = ENOENT;
 648                 pid = -1;
 649         }
 650         else {
 651                 const char *interpr = parse_interpreter(prog);
 652
 653                 if (interpr) {
 654                         const char *argv0 = argv[0];
 655                         char *iprog = path_lookup(interpr, path, 1);
 656                         argv[0] = prog;
 657                         if (!iprog) {
 658                                 errno = ENOENT;
 659                                 pid = -1;
 660                         }
 661                         else {
 662                                 pid = mingw_spawnve(iprog, argv, env, 1);
 663                                 free(iprog);
 664                         }
 665                         argv[0] = argv0;
 666                 }
 667                 else
 668                         pid = mingw_spawnve(prog, argv, env, 0);
 669                 free(prog);
 670         }
 671         free_path_split(path);
 672         return pid;
 673 }
 674
 675 static int try_shell_exec(const char *cmd, char *const *argv, char **env)
 676 {
 677         const char *interpr = parse_interpreter(cmd);
 678         char **path;
 679         char *prog;
 680         int pid = 0;
 681
 682         if (!interpr)
 683                 return 0;
 684         path = get_path_split();
 685         prog = path_lookup(interpr, path, 1);
 686         if (prog) {
 687                 int argc = 0;
 688                 const char **argv2;
 689                 while (argv[argc]) argc++;
 690                 argv2 = xmalloc(sizeof(*argv) * (argc+1));
 691                 argv2[0] = (char *)cmd; /* full path to the script file */
 692                 memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
 693                 pid = mingw_spawnve(prog, argv2, env, 1);
 694                 if (pid >= 0) {
 695                         int status;
 696                         if (waitpid(pid, &status, 0) < 0)
 697                                 status = 255;
 698                         exit(status);
 699                 }
 700                 pid = 1;        /* indicate that we tried but failed */
 701                 free(prog);
 702                 free(argv2);
 703         }
 704         free_path_split(path);
 705         return pid;
 706 }
 707
 708 static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
 709 {
 710         /* check if git_command is a shell script */
 711         if (!try_shell_exec(cmd, argv, (char **)env)) {
 712                 int pid, status;
 713
 714                 pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
 715                 if (pid < 0)
 716                         return;
 717                 if (waitpid(pid, &status, 0) < 0)
 718                         status = 255;
 719                 exit(status);
 720         }
 721 }
 722
 723 void mingw_execvp(const char *cmd, char *const *argv)
 724 {
 725         char **path = get_path_split();
 726         char *prog = path_lookup(cmd, path, 0);
 727
 728         if (prog) {
 729                 mingw_execve(prog, argv, environ);
 730                 free(prog);
 731         } else
 732                 errno = ENOENT;
 733
 734         free_path_split(path);
 735 }
 736
 737 char **copy_environ()
 738 {
 739         char **env;
 740         int i = 0;
 741         while (environ[i])
 742                 i++;
 743         env = xmalloc((i+1)*sizeof(*env));
 744         for (i = 0; environ[i]; i++)
 745                 env[i] = xstrdup(environ[i]);
 746         env[i] = NULL;
 747         return env;
 748 }
 749
 750 void free_environ(char **env)
 751 {
 752         int i;
 753         for (i = 0; env[i]; i++)
 754                 free(env[i]);
 755         free(env);
 756 }
 757
 758 static int lookup_env(char **env, const char *name, size_t nmln)
 759 {
 760         int i;
 761
 762         for (i = 0; env[i]; i++) {
 763                 if (0 == strncmp(env[i], name, nmln)
 764                     && '=' == env[i][nmln])
 765                         /* matches */
 766                         return i;
 767         }
 768         return -1;
 769 }
 770
 771 /*
 772  * If name contains '=', then sets the variable, otherwise it unsets it
 773  */
 774 char **env_setenv(char **env, const char *name)
 775 {
 776         char *eq = strchrnul(name, '=');
 777         int i = lookup_env(env, name, eq-name);
 778
 779         if (i < 0) {
 780                 if (*eq) {
 781                         for (i = 0; env[i]; i++)
 782                                 ;
 783                         env = xrealloc(env, (i+2)*sizeof(*env));
 784                         env[i] = xstrdup(name);
 785                         env[i+1] = NULL;
 786                 }
 787         }
 788         else {
 789                 free(env[i]);
 790                 if (*eq)
 791                         env[i] = xstrdup(name);
 792                 else
 793                         for (; env[i]; i++)
 794                                 env[i] = env[i+1];
 795         }
 796         return env;
 797 }
 798
 799 /* this is the first function to call into WS_32; initialize it */
 800 #undef gethostbyname
 801 struct hostent *mingw_gethostbyname(const char *host)
 802 {
 803         WSADATA wsa;
 804
 805         if (WSAStartup(MAKEWORD(2,2), &wsa))
 806                 die("unable to initialize winsock subsystem, error %d",
 807                         WSAGetLastError());
 808         atexit((void(*)(void)) WSACleanup);
 809         return gethostbyname(host);
 810 }
 811
 812 int mingw_socket(int domain, int type, int protocol)
 813 {
 814         int sockfd;
 815         SOCKET s = WSASocket(domain, type, protocol, NULL, 0, 0);
 816         if (s == INVALID_SOCKET) {
 817                 /*
 818                  * WSAGetLastError() values are regular BSD error codes
 819                  * biased by WSABASEERR.
 820                  * However, strerror() does not know about networking
 821                  * specific errors, which are values beginning at 38 or so.
 822                  * Therefore, we choose to leave the biased error code
 823                  * in errno so that _if_ someone looks up the code somewhere,
 824                  * then it is at least the number that are usually listed.
 825                  */
 826                 errno = WSAGetLastError();
 827                 return -1;
 828         }
 829         /* convert into a file descriptor */
 830         if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
 831                 closesocket(s);
 832                 return error("unable to make a socket file descriptor: %s",
 833                         strerror(errno));
 834         }
 835         return sockfd;
 836 }
 837
 838 #undef connect
 839 int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
 840 {
 841         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
 842         return connect(s, sa, sz);
 843 }
 844
 845 #undef rename
 846 int mingw_rename(const char *pold, const char *pnew)
 847 {
 848         /*
 849          * Try native rename() first to get errno right.
 850          * It is based on MoveFile(), which cannot overwrite existing files.
 851          */
 852         if (!rename(pold, pnew))
 853                 return 0;
 854         if (errno != EEXIST)
 855                 return -1;
 856         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
 857                 return 0;
 858         /* TODO: translate more errors */
 859         if (GetLastError() == ERROR_ACCESS_DENIED) {
 860                 DWORD attrs = GetFileAttributes(pnew);
 861                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY)) {
 862                         errno = EISDIR;
 863                         return -1;
 864                 }
 865         }
 866         errno = EACCES;
 867         return -1;
 868 }
 869
 870 struct passwd *getpwuid(int uid)
 871 {
 872         static char user_name[100];
 873         static struct passwd p;
 874
 875         DWORD len = sizeof(user_name);
 876         if (!GetUserName(user_name, &len))
 877                 return NULL;
 878         p.pw_name = user_name;
 879         p.pw_gecos = "unknown";
 880         p.pw_dir = NULL;
 881         return &p;
 882 }
 883
 884 static HANDLE timer_event;
 885 static HANDLE timer_thread;
 886 static int timer_interval;
 887 static int one_shot;
 888 static sig_handler_t timer_fn = SIG_DFL;
 889
 890 /* The timer works like this:
 891  * The thread, ticktack(), is a trivial routine that most of the time
 892  * only waits to receive the signal to terminate. The main thread tells
 893  * the thread to terminate by setting the timer_event to the signalled
 894  * state.
 895  * But ticktack() interrupts the wait state after the timer's interval
 896  * length to call the signal handler.
 897  */
 898
 899 static __stdcall unsigned ticktack(void *dummy)
 900 {
 901         while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
 902                 if (timer_fn == SIG_DFL)
 903                         die("Alarm");
 904                 if (timer_fn != SIG_IGN)
 905                         timer_fn(SIGALRM);
 906                 if (one_shot)
 907                         break;
 908         }
 909         return 0;
 910 }
 911
 912 static int start_timer_thread(void)
 913 {
 914         timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 915         if (timer_event) {
 916                 timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
 917                 if (!timer_thread )
 918                         return errno = ENOMEM,
 919                                 error("cannot start timer thread");
 920         } else
 921                 return errno = ENOMEM,
 922                         error("cannot allocate resources for timer");
 923         return 0;
 924 }
 925
 926 static void stop_timer_thread(void)
 927 {
 928         if (timer_event)
 929                 SetEvent(timer_event);  /* tell thread to terminate */
 930         if (timer_thread) {
 931                 int rc = WaitForSingleObject(timer_thread, 1000);
 932                 if (rc == WAIT_TIMEOUT)
 933                         error("timer thread did not terminate timely");
 934                 else if (rc != WAIT_OBJECT_0)
 935                         error("waiting for timer thread failed: %lu",
 936                               GetLastError());
 937                 CloseHandle(timer_thread);
 938         }
 939         if (timer_event)
 940                 CloseHandle(timer_event);
 941         timer_event = NULL;
 942         timer_thread = NULL;
 943 }
 944
 945 static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
 946 {
 947         return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
 948 }
 949
 950 int setitimer(int type, struct itimerval *in, struct itimerval *out)
 951 {
 952         static const struct timeval zero;
 953         static int atexit_done;
 954
 955         if (out != NULL)
 956                 return errno = EINVAL,
 957                         error("setitimer param 3 != NULL not implemented");
 958         if (!is_timeval_eq(&in->it_interval, &zero) &&
 959             !is_timeval_eq(&in->it_interval, &in->it_value))
 960                 return errno = EINVAL,
 961                         error("setitimer: it_interval must be zero or eq it_value");
 962
 963         if (timer_thread)
 964                 stop_timer_thread();
 965
 966         if (is_timeval_eq(&in->it_value, &zero) &&
 967             is_timeval_eq(&in->it_interval, &zero))
 968                 return 0;
 969
 970         timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
 971         one_shot = is_timeval_eq(&in->it_interval, &zero);
 972         if (!atexit_done) {
 973                 atexit(stop_timer_thread);
 974                 atexit_done = 1;
 975         }
 976         return start_timer_thread();
 977 }
 978
 979 int sigaction(int sig, struct sigaction *in, struct sigaction *out)
 980 {
 981         if (sig != SIGALRM)
 982                 return errno = EINVAL,
 983                         error("sigaction only implemented for SIGALRM");
 984         if (out != NULL)
 985                 return errno = EINVAL,
 986                         error("sigaction: param 3 != NULL not implemented");
 987
 988         timer_fn = in->sa_handler;
 989         return 0;
 990 }
 991
 992 #undef signal
 993 sig_handler_t mingw_signal(int sig, sig_handler_t handler)
 994 {
 995         if (sig != SIGALRM)
 996                 return signal(sig, handler);
 997         sig_handler_t old = timer_fn;
 998         timer_fn = handler;
 999         return old;
1000 }
1001
1002 static const char *make_backslash_path(const char *path)
1003 {
1004         static char buf[PATH_MAX + 1];
1005         char *c;
1006
1007         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
1008                 die("Too long path: %.*s", 60, path);
1009
1010         for (c = buf; *c; c++) {
1011                 if (*c == '/')
1012                         *c = '\\';
1013         }
1014         return buf;
1015 }
1016
1017 void mingw_open_html(const char *unixpath)
1018 {
1019         const char *htmlpath = make_backslash_path(unixpath);
1020         printf("Launching default browser to display HTML ...\n");
1021         ShellExecute(NULL, "open", htmlpath, NULL, "\\", 0);
1022 }