XHTMLTipOfTheDay - HTML Tip of the Day Dialog

// CreateFileFromResource.cpp  Version 1.1
//
// Author:  Hans Dietrich
//          hdietrich2@hotmail.com
//
// License:
//     This software is released into the public domain.  You are free to use
//     it in any way you like, except that you may not sell this source code.
//
//     This software is provided "as is" with no expressed or implied warranty.
//     I accept no liability for any damage or loss of business that this 
//     software may cause.
//
///////////////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "CreateFileFromResource.h"
#include <io.h>

DWORD CreateFileFromResource(UINT nID,							// resource id
							 LPCTSTR lpszResourceType,			// resource type
							 LPCTSTR lpszFile,					// output file name
							 LPCTSTR lpszDirectory /*= NULL*/,	// directory path
							 BOOL bOverWrite /*= FALSE*/)		// TRUE = overwrite existing file
{
	DWORD dwSize = 0;
	
	ASSERT(nID != 0);
	ASSERT((lpszFile != NULL) && (lpszFile[0] != _T('\0')));
	ASSERT((lpszResourceType != NULL) && (lpszResourceType[0] != _T('\0')));

	if ((nID == 0) ||
		(lpszFile == NULL) || 
		(lpszFile[0] == _T('\0')) ||
		(lpszResourceType == NULL) ||
		(lpszResourceType[0] == _T('\0')))
	{
		TRACE(_T("ERROR - CreateFileFromResource bad args\n"));
		return dwSize;
	}

	CString strFile = _T("");
	if ((lpszDirectory != NULL) && (lpszDirectory[0] != _T('\0')))
	{
		strFile = lpszDirectory;
		strFile.TrimRight();
		if (strFile.Right(1) != _T("\\"))
			strFile += _T("\\");
	}
	strFile += lpszFile;

	TRACE(_T("CreateFileFromResource: strFile=<%s>\n"), strFile);
	
	// check if we should overwrite existing file
	if (!bOverWrite)
	{
		if (_taccess(strFile, 00) == 0)
		{
			TRACE(_T("%s exists, will not overwrite\n"), strFile);
			return dwSize;
		}
	}
	
	// create the output file
	HANDLE hFile = ::CreateFile(strFile,
								GENERIC_READ | GENERIC_WRITE,
								FILE_SHARE_READ | FILE_SHARE_WRITE,
								NULL,
								CREATE_ALWAYS,
								FILE_ATTRIBUTE_NORMAL,
								NULL);

	if (hFile == INVALID_HANDLE_VALUE)
	{
		TRACE(_T("ERROR - failed to create %s\n"), strFile);
		return dwSize;
	}

	// The resource specified by nID is read in as a
	// lpszResourceType resource, and written to the file.
	//
	// In the .rc file, insert a line like the following:
	//
	//     IDU_FOO  TEXT  MOVEABLE PURE  "BAR.TXT"
	//
	// where BAR.TXT is the name of the file that contains the 
	// TEXT resource type.  The resource type specified by
	// lpszResourceType can be any string, including your own 
	// custom types, e.g.:
	//
	//     IDU_FOO  MYTYPE  MOVEABLE PURE  "BAR.DAT"

	TRACE(_T("reading  resource %d\n"), nID);

	HINSTANCE hinst = AfxGetResourceHandle();
	ASSERT(hinst);

	if (hinst)
	{
		HRSRC hrsrc = ::FindResource(hinst, MAKEINTRESOURCE(nID), lpszResourceType);
		ASSERT(hrsrc);

		if (hrsrc)
		{
			// get size of the resource
			dwSize = ::SizeofResource(hinst, hrsrc);
			TRACE(_T("resource dwSize=%u\n"), dwSize);
			ASSERT(dwSize);

			if (dwSize)
			{
				HGLOBAL hglbl = ::LoadResource(hinst, hrsrc);
				ASSERT(hglbl);

				if (hglbl)
				{
					LPTSTR lpBuf = (LPTSTR) ::LockResource(hglbl);
					ASSERT(lpBuf);

					// lpBuf points to first byte of file resource

					if (lpBuf)
					{
						DWORD dwBytesWritten = 0;
						BOOL bRet = ::WriteFile(hFile, lpBuf, dwSize, 
											&dwBytesWritten, NULL);
						if (!bRet)
						{
							dwSize = 0;
							TRACE(_T("ERROR - write failed\n"));
						}
						else
						{
							TRACE(_T("%u bytes written\n"), dwBytesWritten);
						}
	
						::UnlockResource(hglbl);
					}
					else
					{
						TRACE(_T("ERROR - LockResource failed\n"));
						dwSize = 0;
					}

					::FreeResource(hglbl);
				}
				else
				{
					TRACE(_T("ERROR - LoadResource failed\n"));
					dwSize = 0;
				}
			}
		}
	}
	
	::CloseHandle(hFile);

	return dwSize;
}