compat/mingw.c

   1 #include "../git-compat-util.h"
   2 #include "win32.h"
   3 #include "../strbuf.h"
   4
   5 unsigned int _CRT_fmode = _O_BINARY;
   6
   7 #undef open
   8 int mingw_open (const char *filename, int oflags, ...)
   9 {
  10         va_list args;
  11         unsigned mode;
  12         va_start(args, oflags);
  13         mode = va_arg(args, int);
  14         va_end(args);
  15
  16         if (!strcmp(filename, "/dev/null"))
  17                 filename = "nul";
  18         int fd = open(filename, oflags, mode);
  19         if (fd < 0 && (oflags & O_CREAT) && errno == EACCES) {
  20                 DWORD attrs = GetFileAttributes(filename);
  21                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY))
  22                         errno = EISDIR;
  23         }
  24         return fd;
  25 }
  26
  27 static inline time_t filetime_to_time_t(const FILETIME *ft)
  28 {
  29         long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
  30         winTime -= 116444736000000000LL; /* Windows to Unix Epoch conversion */
  31         winTime /= 10000000;             /* Nano to seconds resolution */
  32         return (time_t)winTime;
  33 }
  34
  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 (!(errno = get_file_attr(file_name, &fdata))) {
  44                 buf->st_ino = 0;
  45                 buf->st_gid = 0;
  46                 buf->st_uid = 0;
  47                 buf->st_nlink = 1;
  48                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
  49                 buf->st_size = fdata.nFileSizeLow |
  50                         (((off_t)fdata.nFileSizeHigh)<<32);
  51                 buf->st_dev = buf->st_rdev = 0; /* not used by Git */
  52                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
  53                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
  54                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
  55                 return 0;
  56         }
  57         return -1;
  58 }
  59
  60 /* We provide our own lstat/fstat functions, since the provided
  61  * lstat/fstat functions are so slow. These stat functions are
  62  * tailored for Git's usage (read: fast), and are not meant to be
  63  * complete. Note that Git stat()s are redirected to mingw_lstat()
  64  * too, since Windows doesn't really handle symlinks that well.
  65  */
  66 int mingw_lstat(const char *file_name, struct stat *buf)
  67 {
  68         int namelen;
  69         static char alt_name[PATH_MAX];
  70
  71         if (!do_lstat(file_name, buf))
  72                 return 0;
  73
  74         /* if file_name ended in a '/', Windows returned ENOENT;
  75          * try again without trailing slashes
  76          */
  77         if (errno != ENOENT)
  78                 return -1;
  79
  80         namelen = strlen(file_name);
  81         if (namelen && file_name[namelen-1] != '/')
  82                 return -1;
  83         while (namelen && file_name[namelen-1] == '/')
  84                 --namelen;
  85         if (!namelen || namelen >= PATH_MAX)
  86                 return -1;
  87
  88         memcpy(alt_name, file_name, namelen);
  89         alt_name[namelen] = 0;
  90         return do_lstat(alt_name, buf);
  91 }
  92
  93 #undef fstat
  94 int mingw_fstat(int fd, struct stat *buf)
  95 {
  96         HANDLE fh = (HANDLE)_get_osfhandle(fd);
  97         BY_HANDLE_FILE_INFORMATION fdata;
  98
  99         if (fh == INVALID_HANDLE_VALUE) {
 100                 errno = EBADF;
 101                 return -1;
 102         }
 103         /* direct non-file handles to MS's fstat() */
 104         if (GetFileType(fh) != FILE_TYPE_DISK)
 105                 return _fstati64(fd, buf);
 106
 107         if (GetFileInformationByHandle(fh, &fdata)) {
 108                 buf->st_ino = 0;
 109                 buf->st_gid = 0;
 110                 buf->st_uid = 0;
 111                 buf->st_nlink = 1;
 112                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
 113                 buf->st_size = fdata.nFileSizeLow |
 114                         (((off_t)fdata.nFileSizeHigh)<<32);
 115                 buf->st_dev = buf->st_rdev = 0; /* not used by Git */
 116                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
 117                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
 118                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
 119                 return 0;
 120         }
 121         errno = EBADF;
 122         return -1;
 123 }
 124
 125 static inline void time_t_to_filetime(time_t t, FILETIME *ft)
 126 {
 127         long long winTime = t * 10000000LL + 116444736000000000LL;
 128         ft->dwLowDateTime = winTime;
 129         ft->dwHighDateTime = winTime >> 32;
 130 }
 131
 132 int mingw_utime (const char *file_name, const struct utimbuf *times)
 133 {
 134         FILETIME mft, aft;
 135         int fh, rc;
 136
 137         /* must have write permission */
 138         if ((fh = open(file_name, O_RDWR | O_BINARY)) < 0)
 139                 return -1;
 140
 141         time_t_to_filetime(times->modtime, &mft);
 142         time_t_to_filetime(times->actime, &aft);
 143         if (!SetFileTime((HANDLE)_get_osfhandle(fh), NULL, &aft, &mft)) {
 144                 errno = EINVAL;
 145                 rc = -1;
 146         } else
 147                 rc = 0;
 148         close(fh);
 149         return rc;
 150 }
 151
 152 unsigned int sleep (unsigned int seconds)
 153 {
 154         Sleep(seconds*1000);
 155         return 0;
 156 }
 157
 158 int mkstemp(char *template)
 159 {
 160         char *filename = mktemp(template);
 161         if (filename == NULL)
 162                 return -1;
 163         return open(filename, O_RDWR | O_CREAT, 0600);
 164 }
 165
 166 int gettimeofday(struct timeval *tv, void *tz)
 167 {
 168         SYSTEMTIME st;
 169         struct tm tm;
 170         GetSystemTime(&st);
 171         tm.tm_year = st.wYear-1900;
 172         tm.tm_mon = st.wMonth-1;
 173         tm.tm_mday = st.wDay;
 174         tm.tm_hour = st.wHour;
 175         tm.tm_min = st.wMinute;
 176         tm.tm_sec = st.wSecond;
 177         tv->tv_sec = tm_to_time_t(&tm);
 178         if (tv->tv_sec < 0)
 179                 return -1;
 180         tv->tv_usec = st.wMilliseconds*1000;
 181         return 0;
 182 }
 183
 184 int pipe(int filedes[2])
 185 {
 186         int fd;
 187         HANDLE h[2], parent;
 188
 189         if (_pipe(filedes, 8192, 0) < 0)
 190                 return -1;
 191
 192         parent = GetCurrentProcess();
 193
 194         if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[0]),
 195                         parent, &h[0], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
 196                 close(filedes[0]);
 197                 close(filedes[1]);
 198                 return -1;
 199         }
 200         if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[1]),
 201                         parent, &h[1], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
 202                 close(filedes[0]);
 203                 close(filedes[1]);
 204                 CloseHandle(h[0]);
 205                 return -1;
 206         }
 207         fd = _open_osfhandle((int)h[0], O_NOINHERIT);
 208         if (fd < 0) {
 209                 close(filedes[0]);
 210                 close(filedes[1]);
 211                 CloseHandle(h[0]);
 212                 CloseHandle(h[1]);
 213                 return -1;
 214         }
 215         close(filedes[0]);
 216         filedes[0] = fd;
 217         fd = _open_osfhandle((int)h[1], O_NOINHERIT);
 218         if (fd < 0) {
 219                 close(filedes[0]);
 220                 close(filedes[1]);
 221                 CloseHandle(h[1]);
 222                 return -1;
 223         }
 224         close(filedes[1]);
 225         filedes[1] = fd;
 226         return 0;
 227 }
 228
 229 int poll(struct pollfd *ufds, unsigned int nfds, int timeout)
 230 {
 231         int i, pending;
 232
 233         if (timeout >= 0) {
 234                 if (nfds == 0) {
 235                         Sleep(timeout);
 236                         return 0;
 237                 }
 238                 return errno = EINVAL, error("poll timeout not supported");
 239         }
 240
 241         /* When there is only one fd to wait for, then we pretend that
 242          * input is available and let the actual wait happen when the
 243          * caller invokes read().
 244          */
 245         if (nfds == 1) {
 246                 if (!(ufds[0].events & POLLIN))
 247                         return errno = EINVAL, error("POLLIN not set");
 248                 ufds[0].revents = POLLIN;
 249                 return 0;
 250         }
 251
 252 repeat:
 253         pending = 0;
 254         for (i = 0; i < nfds; i++) {
 255                 DWORD avail = 0;
 256                 HANDLE h = (HANDLE) _get_osfhandle(ufds[i].fd);
 257                 if (h == INVALID_HANDLE_VALUE)
 258                         return -1;      /* errno was set */
 259
 260                 if (!(ufds[i].events & POLLIN))
 261                         return errno = EINVAL, error("POLLIN not set");
 262
 263                 /* this emulation works only for pipes */
 264                 if (!PeekNamedPipe(h, NULL, 0, NULL, &avail, NULL)) {
 265                         int err = GetLastError();
 266                         if (err == ERROR_BROKEN_PIPE) {
 267                                 ufds[i].revents = POLLHUP;
 268                                 pending++;
 269                         } else {
 270                                 errno = EINVAL;
 271                                 return error("PeekNamedPipe failed,"
 272                                         " GetLastError: %u", err);
 273                         }
 274                 } else if (avail) {
 275                         ufds[i].revents = POLLIN;
 276                         pending++;
 277                 } else
 278                         ufds[i].revents = 0;
 279         }
 280         if (!pending) {
 281                 /* The only times that we spin here is when the process
 282                  * that is connected through the pipes is waiting for
 283                  * its own input data to become available. But since
 284                  * the process (pack-objects) is itself CPU intensive,
 285                  * it will happily pick up the time slice that we are
 286                  * relinguishing here.
 287                  */
 288                 Sleep(0);
 289                 goto repeat;
 290         }
 291         return 0;
 292 }
 293
 294 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 295 {
 296         /* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 297         memcpy(result, gmtime(timep), sizeof(struct tm));
 298         return result;
 299 }
 300
 301 struct tm *localtime_r(const time_t *timep, struct tm *result)
 302 {
 303         /* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 304         memcpy(result, localtime(timep), sizeof(struct tm));
 305         return result;
 306 }
 307
 308 #undef getcwd
 309 char *mingw_getcwd(char *pointer, int len)
 310 {
 311         int i;
 312         char *ret = getcwd(pointer, len);
 313         if (!ret)
 314                 return ret;
 315         for (i = 0; pointer[i]; i++)
 316                 if (pointer[i] == '\\')
 317                         pointer[i] = '/';
 318         return ret;
 319 }
 320
 321 #undef getenv
 322 char *mingw_getenv(const char *name)
 323 {
 324         char *result = getenv(name);
 325         if (!result && !strcmp(name, "TMPDIR")) {
 326                 /* on Windows it is TMP and TEMP */
 327                 result = getenv("TMP");
 328                 if (!result)
 329                         result = getenv("TEMP");
 330         }
 331         return result;
 332 }
 333
 334 /*
 335  * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
 336  * (Parsing C++ Command-Line Arguments)
 337  */
 338 static const char *quote_arg(const char *arg)
 339 {
 340         /* count chars to quote */
 341         int len = 0, n = 0;
 342         int force_quotes = 0;
 343         char *q, *d;
 344         const char *p = arg;
 345         if (!*p) force_quotes = 1;
 346         while (*p) {
 347                 if (isspace(*p) || *p == '*' || *p == '?' || *p == '{')
 348                         force_quotes = 1;
 349                 else if (*p == '"')
 350                         n++;
 351                 else if (*p == '\\') {
 352                         int count = 0;
 353                         while (*p == '\\') {
 354                                 count++;
 355                                 p++;
 356                                 len++;
 357                         }
 358                         if (*p == '"')
 359                                 n += count*2 + 1;
 360                         continue;
 361                 }
 362                 len++;
 363                 p++;
 364         }
 365         if (!force_quotes && n == 0)
 366                 return arg;
 367
 368         /* insert \ where necessary */
 369         d = q = xmalloc(len+n+3);
 370         *d++ = '"';
 371         while (*arg) {
 372                 if (*arg == '"')
 373                         *d++ = '\\';
 374                 else if (*arg == '\\') {
 375                         int count = 0;
 376                         while (*arg == '\\') {
 377                                 count++;
 378                                 *d++ = *arg++;
 379                         }
 380                         if (*arg == '"') {
 381                                 while (count-- > 0)
 382                                         *d++ = '\\';
 383                                 *d++ = '\\';
 384                         }
 385                 }
 386                 *d++ = *arg++;
 387         }
 388         *d++ = '"';
 389         *d++ = 0;
 390         return q;
 391 }
 392
 393 static const char *parse_interpreter(const char *cmd)
 394 {
 395         static char buf[100];
 396         char *p, *opt;
 397         int n, fd;
 398
 399         /* don't even try a .exe */
 400         n = strlen(cmd);
 401         if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
 402                 return NULL;
 403
 404         fd = open(cmd, O_RDONLY);
 405         if (fd < 0)
 406                 return NULL;
 407         n = read(fd, buf, sizeof(buf)-1);
 408         close(fd);
 409         if (n < 4)      /* at least '#!/x' and not error */
 410                 return NULL;
 411
 412         if (buf[0] != '#' || buf[1] != '!')
 413                 return NULL;
 414         buf[n] = '\0';
 415         p = strchr(buf, '\n');
 416         if (!p)
 417                 return NULL;
 418
 419         *p = '\0';
 420         if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
 421                 return NULL;
 422         /* strip options */
 423         if ((opt = strchr(p+1, ' ')))
 424                 *opt = '\0';
 425         return p+1;
 426 }
 427
 428 /*
 429  * Splits the PATH into parts.
 430  */
 431 static char **get_path_split(void)
 432 {
 433         char *p, **path, *envpath = getenv("PATH");
 434         int i, n = 0;
 435
 436         if (!envpath || !*envpath)
 437                 return NULL;
 438
 439         envpath = xstrdup(envpath);
 440         p = envpath;
 441         while (p) {
 442                 char *dir = p;
 443                 p = strchr(p, ';');
 444                 if (p) *p++ = '\0';
 445                 if (*dir) {     /* not earlier, catches series of ; */
 446                         ++n;
 447                 }
 448         }
 449         if (!n)
 450                 return NULL;
 451
 452         path = xmalloc((n+1)*sizeof(char*));
 453         p = envpath;
 454         i = 0;
 455         do {
 456                 if (*p)
 457                         path[i++] = xstrdup(p);
 458                 p = p+strlen(p)+1;
 459         } while (i < n);
 460         path[i] = NULL;
 461
 462         free(envpath);
 463
 464         return path;
 465 }
 466
 467 static void free_path_split(char **path)
 468 {
 469         if (!path)
 470                 return;
 471
 472         char **p = path;
 473         while (*p)
 474                 free(*p++);
 475         free(path);
 476 }
 477
 478 /*
 479  * exe_only means that we only want to detect .exe files, but not scripts
 480  * (which do not have an extension)
 481  */
 482 static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
 483 {
 484         char path[MAX_PATH];
 485         snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
 486
 487         if (!isexe && access(path, F_OK) == 0)
 488                 return xstrdup(path);
 489         path[strlen(path)-4] = '\0';
 490         if ((!exe_only || isexe) && access(path, F_OK) == 0)
 491                 if (!(GetFileAttributes(path) & FILE_ATTRIBUTE_DIRECTORY))
 492                         return xstrdup(path);
 493         return NULL;
 494 }
 495
 496 /*
 497  * Determines the absolute path of cmd using the the split path in path.
 498  * If cmd contains a slash or backslash, no lookup is performed.
 499  */
 500 static char *path_lookup(const char *cmd, char **path, int exe_only)
 501 {
 502         char *prog = NULL;
 503         int len = strlen(cmd);
 504         int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 505
 506         if (strchr(cmd, '/') || strchr(cmd, '\\'))
 507                 prog = xstrdup(cmd);
 508
 509         while (!prog && *path)
 510                 prog = lookup_prog(*path++, cmd, isexe, exe_only);
 511
 512         return prog;
 513 }
 514
 515 static int env_compare(const void *a, const void *b)
 516 {
 517         char *const *ea = a;
 518         char *const *eb = b;
 519         return strcasecmp(*ea, *eb);
 520 }
 521
 522 static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
 523                            int prepend_cmd)
 524 {
 525         STARTUPINFO si;
 526         PROCESS_INFORMATION pi;
 527         struct strbuf envblk, args;
 528         unsigned flags;
 529         BOOL ret;
 530
 531         /* Determine whether or not we are associated to a console */
 532         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
 533                         FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 534                         FILE_ATTRIBUTE_NORMAL, NULL);
 535         if (cons == INVALID_HANDLE_VALUE) {
 536                 /* There is no console associated with this process.
 537                  * Since the child is a console process, Windows
 538                  * would normally create a console window. But
 539                  * since we'll be redirecting std streams, we do
 540                  * not need the console.
 541                  * It is necessary to use DETACHED_PROCESS
 542                  * instead of CREATE_NO_WINDOW to make ssh
 543                  * recognize that it has no console.
 544                  */
 545                 flags = DETACHED_PROCESS;
 546         } else {
 547                 /* There is already a console. If we specified
 548                  * DETACHED_PROCESS here, too, Windows would
 549                  * disassociate the child from the console.
 550                  * The same is true for CREATE_NO_WINDOW.
 551                  * Go figure!
 552                  */
 553                 flags = 0;
 554                 CloseHandle(cons);
 555         }
 556         memset(&si, 0, sizeof(si));
 557         si.cb = sizeof(si);
 558         si.dwFlags = STARTF_USESTDHANDLES;
 559         si.hStdInput = (HANDLE) _get_osfhandle(0);
 560         si.hStdOutput = (HANDLE) _get_osfhandle(1);
 561         si.hStdError = (HANDLE) _get_osfhandle(2);
 562
 563         /* concatenate argv, quoting args as we go */
 564         strbuf_init(&args, 0);
 565         if (prepend_cmd) {
 566                 char *quoted = (char *)quote_arg(cmd);
 567                 strbuf_addstr(&args, quoted);
 568                 if (quoted != cmd)
 569                         free(quoted);
 570         }
 571         for (; *argv; argv++) {
 572                 char *quoted = (char *)quote_arg(*argv);
 573                 if (*args.buf)
 574                         strbuf_addch(&args, ' ');
 575                 strbuf_addstr(&args, quoted);
 576                 if (quoted != *argv)
 577                         free(quoted);
 578         }
 579
 580         if (env) {
 581                 int count = 0;
 582                 char **e, **sorted_env;
 583
 584                 for (e = env; *e; e++)
 585                         count++;
 586
 587                 /* environment must be sorted */
 588                 sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
 589                 memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
 590                 qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
 591
 592                 strbuf_init(&envblk, 0);
 593                 for (e = sorted_env; *e; e++) {
 594                         strbuf_addstr(&envblk, *e);
 595                         strbuf_addch(&envblk, '\0');
 596                 }
 597                 free(sorted_env);
 598         }
 599
 600         memset(&pi, 0, sizeof(pi));
 601         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
 602                 env ? envblk.buf : NULL, NULL, &si, &pi);
 603
 604         if (env)
 605                 strbuf_release(&envblk);
 606         strbuf_release(&args);
 607
 608         if (!ret) {
 609                 errno = ENOENT;
 610                 return -1;
 611         }
 612         CloseHandle(pi.hThread);
 613         return (pid_t)pi.hProcess;
 614 }
 615
 616 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env)
 617 {
 618         pid_t pid;
 619         char **path = get_path_split();
 620         char *prog = path_lookup(cmd, path, 0);
 621
 622         if (!prog) {
 623                 errno = ENOENT;
 624                 pid = -1;
 625         }
 626         else {
 627                 const char *interpr = parse_interpreter(prog);
 628
 629                 if (interpr) {
 630                         const char *argv0 = argv[0];
 631                         char *iprog = path_lookup(interpr, path, 1);
 632                         argv[0] = prog;
 633                         if (!iprog) {
 634                                 errno = ENOENT;
 635                                 pid = -1;
 636                         }
 637                         else {
 638                                 pid = mingw_spawnve(iprog, argv, env, 1);
 639                                 free(iprog);
 640                         }
 641                         argv[0] = argv0;
 642                 }
 643                 else
 644                         pid = mingw_spawnve(prog, argv, env, 0);
 645                 free(prog);
 646         }
 647         free_path_split(path);
 648         return pid;
 649 }
 650
 651 static int try_shell_exec(const char *cmd, char *const *argv, char **env)
 652 {
 653         const char *interpr = parse_interpreter(cmd);
 654         char **path;
 655         char *prog;
 656         int pid = 0;
 657
 658         if (!interpr)
 659                 return 0;
 660         path = get_path_split();
 661         prog = path_lookup(interpr, path, 1);
 662         if (prog) {
 663                 int argc = 0;
 664                 const char **argv2;
 665                 while (argv[argc]) argc++;
 666                 argv2 = xmalloc(sizeof(*argv) * (argc+1));
 667                 argv2[0] = (char *)cmd; /* full path to the script file */
 668                 memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
 669                 pid = mingw_spawnve(prog, argv2, env, 1);
 670                 if (pid >= 0) {
 671                         int status;
 672                         if (waitpid(pid, &status, 0) < 0)
 673                                 status = 255;
 674                         exit(status);
 675                 }
 676                 pid = 1;        /* indicate that we tried but failed */
 677                 free(prog);
 678                 free(argv2);
 679         }
 680         free_path_split(path);
 681         return pid;
 682 }
 683
 684 static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
 685 {
 686         /* check if git_command is a shell script */
 687         if (!try_shell_exec(cmd, argv, (char **)env)) {
 688                 int pid, status;
 689
 690                 pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
 691                 if (pid < 0)
 692                         return;
 693                 if (waitpid(pid, &status, 0) < 0)
 694                         status = 255;
 695                 exit(status);
 696         }
 697 }
 698
 699 void mingw_execvp(const char *cmd, char *const *argv)
 700 {
 701         char **path = get_path_split();
 702         char *prog = path_lookup(cmd, path, 0);
 703
 704         if (prog) {
 705                 mingw_execve(prog, argv, environ);
 706                 free(prog);
 707         } else
 708                 errno = ENOENT;
 709
 710         free_path_split(path);
 711 }
 712
 713 char **copy_environ()
 714 {
 715         char **env;
 716         int i = 0;
 717         while (environ[i])
 718                 i++;
 719         env = xmalloc((i+1)*sizeof(*env));
 720         for (i = 0; environ[i]; i++)
 721                 env[i] = xstrdup(environ[i]);
 722         env[i] = NULL;
 723         return env;
 724 }
 725
 726 void free_environ(char **env)
 727 {
 728         int i;
 729         for (i = 0; env[i]; i++)
 730                 free(env[i]);
 731         free(env);
 732 }
 733
 734 static int lookup_env(char **env, const char *name, size_t nmln)
 735 {
 736         int i;
 737
 738         for (i = 0; env[i]; i++) {
 739                 if (0 == strncmp(env[i], name, nmln)
 740                     && '=' == env[i][nmln])
 741                         /* matches */
 742                         return i;
 743         }
 744         return -1;
 745 }
 746
 747 /*
 748  * If name contains '=', then sets the variable, otherwise it unsets it
 749  */
 750 char **env_setenv(char **env, const char *name)
 751 {
 752         char *eq = strchrnul(name, '=');
 753         int i = lookup_env(env, name, eq-name);
 754
 755         if (i < 0) {
 756                 if (*eq) {
 757                         for (i = 0; env[i]; i++)
 758                                 ;
 759                         env = xrealloc(env, (i+2)*sizeof(*env));
 760                         env[i] = xstrdup(name);
 761                         env[i+1] = NULL;
 762                 }
 763         }
 764         else {
 765                 free(env[i]);
 766                 if (*eq)
 767                         env[i] = xstrdup(name);
 768                 else
 769                         for (; env[i]; i++)
 770                                 env[i] = env[i+1];
 771         }
 772         return env;
 773 }
 774
 775 /* this is the first function to call into WS_32; initialize it */
 776 #undef gethostbyname
 777 struct hostent *mingw_gethostbyname(const char *host)
 778 {
 779         WSADATA wsa;
 780
 781         if (WSAStartup(MAKEWORD(2,2), &wsa))
 782                 die("unable to initialize winsock subsystem, error %d",
 783                         WSAGetLastError());
 784         atexit((void(*)(void)) WSACleanup);
 785         return gethostbyname(host);
 786 }
 787
 788 int mingw_socket(int domain, int type, int protocol)
 789 {
 790         int sockfd;
 791         SOCKET s = WSASocket(domain, type, protocol, NULL, 0, 0);
 792         if (s == INVALID_SOCKET) {
 793                 /*
 794                  * WSAGetLastError() values are regular BSD error codes
 795                  * biased by WSABASEERR.
 796                  * However, strerror() does not know about networking
 797                  * specific errors, which are values beginning at 38 or so.
 798                  * Therefore, we choose to leave the biased error code
 799                  * in errno so that _if_ someone looks up the code somewhere,
 800                  * then it is at least the number that are usually listed.
 801                  */
 802                 errno = WSAGetLastError();
 803                 return -1;
 804         }
 805         /* convert into a file descriptor */
 806         if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
 807                 closesocket(s);
 808                 return error("unable to make a socket file descriptor: %s",
 809                         strerror(errno));
 810         }
 811         return sockfd;
 812 }
 813
 814 #undef connect
 815 int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
 816 {
 817         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
 818         return connect(s, sa, sz);
 819 }
 820
 821 #undef rename
 822 int mingw_rename(const char *pold, const char *pnew)
 823 {
 824         DWORD attrs;
 825
 826         /*
 827          * Try native rename() first to get errno right.
 828          * It is based on MoveFile(), which cannot overwrite existing files.
 829          */
 830         if (!rename(pold, pnew))
 831                 return 0;
 832         if (errno != EEXIST)
 833                 return -1;
 834         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
 835                 return 0;
 836         /* TODO: translate more errors */
 837         if (GetLastError() == ERROR_ACCESS_DENIED &&
 838             (attrs = GetFileAttributes(pnew)) != INVALID_FILE_ATTRIBUTES) {
 839                 if (attrs & FILE_ATTRIBUTE_DIRECTORY) {
 840                         errno = EISDIR;
 841                         return -1;
 842                 }
 843                 if ((attrs & FILE_ATTRIBUTE_READONLY) &&
 844                     SetFileAttributes(pnew, attrs & ~FILE_ATTRIBUTE_READONLY)) {
 845                         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
 846                                 return 0;
 847                         /* revert file attributes on failure */
 848                         SetFileAttributes(pnew, attrs);
 849                 }
 850         }
 851         errno = EACCES;
 852         return -1;
 853 }
 854
 855 struct passwd *getpwuid(int uid)
 856 {
 857         static char user_name[100];
 858         static struct passwd p;
 859
 860         DWORD len = sizeof(user_name);
 861         if (!GetUserName(user_name, &len))
 862                 return NULL;
 863         p.pw_name = user_name;
 864         p.pw_gecos = "unknown";
 865         p.pw_dir = NULL;
 866         return &p;
 867 }
 868
 869 static HANDLE timer_event;
 870 static HANDLE timer_thread;
 871 static int timer_interval;
 872 static int one_shot;
 873 static sig_handler_t timer_fn = SIG_DFL;
 874
 875 /* The timer works like this:
 876  * The thread, ticktack(), is a trivial routine that most of the time
 877  * only waits to receive the signal to terminate. The main thread tells
 878  * the thread to terminate by setting the timer_event to the signalled
 879  * state.
 880  * But ticktack() interrupts the wait state after the timer's interval
 881  * length to call the signal handler.
 882  */
 883
 884 static __stdcall unsigned ticktack(void *dummy)
 885 {
 886         while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
 887                 if (timer_fn == SIG_DFL)
 888                         die("Alarm");
 889                 if (timer_fn != SIG_IGN)
 890                         timer_fn(SIGALRM);
 891                 if (one_shot)
 892                         break;
 893         }
 894         return 0;
 895 }
 896
 897 static int start_timer_thread(void)
 898 {
 899         timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
 900         if (timer_event) {
 901                 timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
 902                 if (!timer_thread )
 903                         return errno = ENOMEM,
 904                                 error("cannot start timer thread");
 905         } else
 906                 return errno = ENOMEM,
 907                         error("cannot allocate resources for timer");
 908         return 0;
 909 }
 910
 911 static void stop_timer_thread(void)
 912 {
 913         if (timer_event)
 914                 SetEvent(timer_event);  /* tell thread to terminate */
 915         if (timer_thread) {
 916                 int rc = WaitForSingleObject(timer_thread, 1000);
 917                 if (rc == WAIT_TIMEOUT)
 918                         error("timer thread did not terminate timely");
 919                 else if (rc != WAIT_OBJECT_0)
 920                         error("waiting for timer thread failed: %lu",
 921                               GetLastError());
 922                 CloseHandle(timer_thread);
 923         }
 924         if (timer_event)
 925                 CloseHandle(timer_event);
 926         timer_event = NULL;
 927         timer_thread = NULL;
 928 }
 929
 930 static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
 931 {
 932         return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
 933 }
 934
 935 int setitimer(int type, struct itimerval *in, struct itimerval *out)
 936 {
 937         static const struct timeval zero;
 938         static int atexit_done;
 939
 940         if (out != NULL)
 941                 return errno = EINVAL,
 942                         error("setitimer param 3 != NULL not implemented");
 943         if (!is_timeval_eq(&in->it_interval, &zero) &&
 944             !is_timeval_eq(&in->it_interval, &in->it_value))
 945                 return errno = EINVAL,
 946                         error("setitimer: it_interval must be zero or eq it_value");
 947
 948         if (timer_thread)
 949                 stop_timer_thread();
 950
 951         if (is_timeval_eq(&in->it_value, &zero) &&
 952             is_timeval_eq(&in->it_interval, &zero))
 953                 return 0;
 954
 955         timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
 956         one_shot = is_timeval_eq(&in->it_interval, &zero);
 957         if (!atexit_done) {
 958                 atexit(stop_timer_thread);
 959                 atexit_done = 1;
 960         }
 961         return start_timer_thread();
 962 }
 963
 964 int sigaction(int sig, struct sigaction *in, struct sigaction *out)
 965 {
 966         if (sig != SIGALRM)
 967                 return errno = EINVAL,
 968                         error("sigaction only implemented for SIGALRM");
 969         if (out != NULL)
 970                 return errno = EINVAL,
 971                         error("sigaction: param 3 != NULL not implemented");
 972
 973         timer_fn = in->sa_handler;
 974         return 0;
 975 }
 976
 977 #undef signal
 978 sig_handler_t mingw_signal(int sig, sig_handler_t handler)
 979 {
 980         if (sig != SIGALRM)
 981                 return signal(sig, handler);
 982         sig_handler_t old = timer_fn;
 983         timer_fn = handler;
 984         return old;
 985 }
 986
 987 static const char *make_backslash_path(const char *path)
 988 {
 989         static char buf[PATH_MAX + 1];
 990         char *c;
 991
 992         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 993                 die("Too long path: %.*s", 60, path);
 994
 995         for (c = buf; *c; c++) {
 996                 if (*c == '/')
 997                         *c = '\\';
 998         }
 999         return buf;
1000 }
1001
1002 void mingw_open_html(const char *unixpath)
1003 {
1004         const char *htmlpath = make_backslash_path(unixpath);
1005         printf("Launching default browser to display HTML ...\n");
1006         ShellExecute(NULL, "open", htmlpath, NULL, "\\", 0);
1007 }