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