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