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−/* Emulate link on platforms that lack it, namely native Windows platforms.
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−
+
−   Copyright (C) 2009 Free Software Foundation, Inc.
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−
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−   This program is free software; you can redistribute it and/or modify
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−   it under the terms of the GNU General Public License as published by
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−   the Free Software Foundation; either version 2, or (at your option)
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−   any later version.
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−
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−   This program is distributed in the hope that it will be useful,
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−   but WITHOUT ANY WARRANTY; without even the implied warranty of
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−   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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−   GNU General Public License for more details.
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−
+
−   You should have received a copy of the GNU General Public License
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−   along with this program; if not, write to the Free Software Foundation,
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−   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
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−
+
−#include <config.h>
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−
+
−#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
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−
+
−#define WIN32_LEAN_AND_MEAN
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−#include <unistd.h>
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−#include <windows.h>
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−
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−#include <errno.h>
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−
+
−/* CreateHardLink was introduced only in Windows 2000.  */
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−typedef BOOL (WINAPI * CreateHardLinkFuncType) (LPCTSTR lpFileName,
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−						LPCTSTR lpExistingFileName,
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−						LPSECURITY_ATTRIBUTES lpSecurityAttributes);
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−static CreateHardLinkFuncType CreateHardLinkFunc = NULL;
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−static BOOL initialized = FALSE;
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−
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−static void
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−initialize (void)
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−{
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−  HMODULE kernel32 = LoadLibrary ("kernel32.dll");
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−  if (kernel32 != NULL)
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−    {
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−      CreateHardLinkFunc =
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−	(CreateHardLinkFuncType) GetProcAddress (kernel32, "CreateHardLinkA");
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−    }
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−  initialized = TRUE;
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−}
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−
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−int
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−link (const char *path1, const char *path2)
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−{
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−  if (!initialized)
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−    initialize ();
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−  if (CreateHardLinkFunc == NULL)
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−    {
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−      /* System does not support hard links.  */
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−      errno = EPERM;
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−      return -1;
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−    }
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−  if (CreateHardLinkFunc (path2, path1, NULL) == 0)
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−    {
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−      /* It is not documented which errors CreateHardLink() can produce.
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−       * The following conversions are based on tests on a Windows XP SP2
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−       * system. */
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−      DWORD err = GetLastError ();
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−      switch (err)
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−	{
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−	case ERROR_ACCESS_DENIED:
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−	  errno = EACCES;
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−	  break;
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−
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−	case ERROR_INVALID_FUNCTION:	/* fs does not support hard links */
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−	  errno = EPERM;
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−	  break;
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−
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−	case ERROR_NOT_SAME_DEVICE:
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−	  errno = EXDEV;
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−	  break;
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−
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−	case ERROR_PATH_NOT_FOUND:
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−	case ERROR_FILE_NOT_FOUND:
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−	  errno = ENOENT;
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−	  break;
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−
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−	case ERROR_INVALID_PARAMETER:
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−	  errno = ENAMETOOLONG;
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−	  break;
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−
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−	case ERROR_TOO_MANY_LINKS:
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−	  errno = EMLINK;
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−	  break;
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−
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−	case ERROR_ALREADY_EXISTS:
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−	  errno = EEXIST;
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−	  break;
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−
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−	default:
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−	  errno = EIO;
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−	}
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−      return -1;
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−    }
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−
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−  return 0;
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−}
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−
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−#else /* !Windows */
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−
+
−#error "This platform lacks a link function, and Gnulib doesn't provide a replacement. This is a bug in Gnulib."
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−
+
−#endif /* !Windows */