u_long GetFileSizeInBytesByName(
    char *pchFile
    ) 
{
    int fd = -1;
    u_long ulFileSize = 0;
    
    do
    {
        if( (fd = open(pchFile, O_RDONLY)) < 0 )
        {
            break;
        }
        
        ulFileSize = lseek(fd, 0, SEEK_END);
    }
    while( false );
    
    if( fd != -1 )
        close(fd);

    return ulFileSize;
}

bool CopyFile(
    char  *pchSrc,
    char  *pchDst,
    int64  iBlockSize // iBlockSize = 65536
    )
{
    bool bResult = false;
    int iSrcFd = -1;
    int iDstFd = -1;
    u_char *puchData = NULL;
    int64 iSrcFileSize = 0; 
    int64 iReadBlock = 0;

    do
    {
        puchData = (u_char*)malloc(iBlockSize); 
    
        if( puchData == NULL )
            break;
    
        iSrcFd = open(pchSrc, O_RDONLY);
    
        if( iSrcFd == -1 )
        {
            break;
        }
        
        iDstFd = open(pchDst, O_RDWR|O_CREAT|O_APPEND);
    
        if( iDstFd == -1 )
        {
            break;
        }    
            
        iSrcFileSize = (int64)GetFileSizeInBytesByName(pchSrc);
        
        if( iSrcFileSize == 0 )
        {
            break;
        }
        
        while( iSrcFileSize > 0 )
        {
            if( iSrcFileSize < iBlockSize )
                iReadBlock = iSrcFileSize;
            else
                iReadBlock = iBlockSize;
                
            if( read(iSrcFd, (u_char*)puchData, iReadBlock) <= 0 )
            {
                break;
            }

            if( write(iDstFd, (u_char*)puchData, iReadBlock) <= 0 )
            {
                break;
            }
            
            iSrcFileSize -= iReadBlock;
        }            
            
        if( iSrcFileSize <= 0 )
            bResult = true;
    }
    while( false );    

    if( puchData != NULL )
        free(puchData);
    if( iSrcFd != -1 )
        close(iSrcFd);
    if( iDstFd != -1 )
        close(iDstFd);
    
    return bResult;
}