/*=========================================================================
                                                                                
  Program:   gdcm
  Module:    $RCSfile: gdcmUtil.cxx,v $
  Language:  C++
  Date:      $Date: 2005/01/15 03:49:49 $
  Version:   $Revision: 1.91 $
                                                                                
  Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
  l'Image). All rights reserved. See Doc/License.txt or
  http://www.creatis.insa-lyon.fr/Public/Gdcm/License.html for details.
                                                                                
     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.
                                                                                
=========================================================================*/

#include "gdcmUtil.h"
#include "gdcmDebug.h"
#include <iostream>

// For GetCurrentDate, GetCurrentTime
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <stdarg.h>  //only included in implementation file
#include <stdio.h>   //only included in implementation file

#if defined(_MSC_VER)
   #include <winsock.h>  // for gethostname & gethostbyname
   #undef GetCurrentTime
#else
#ifndef __BORLANDC__
   #include <unistd.h>  // for gethostname
   #include <netdb.h>   // for gethostbyname
#endif
#endif

// For GetMACAddress
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>

#ifdef _WIN32
#include <snmp.h>
#include <conio.h>
#else
#include <strings.h> //for bzero on unix
#endif

#if defined(__linux__) || defined(__CYGWIN__)
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#endif
#ifdef __linux__
#include <linux/if.h>
#endif

#ifdef __FreeBSD__
#include <sys/types.h>
#include <sys/socket.h>
#include <ifaddrs.h>
#include <net/if_dl.h>
#endif

#ifdef __HP_aCC
#include <netio.h>
#endif

#ifdef _AIX
#include <sys/ndd_var.h>
#include <sys/kinfo.h>
#endif

#ifdef __APPLE__
#include <CoreFoundation/CoreFoundation.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/network/IOEthernetInterface.h>
#include <IOKit/network/IONetworkInterface.h>
#include <IOKit/network/IOEthernetController.h>
#endif //__APPLE__
// End For GetMACAddress

namespace gdcm 
{
/**
 * \ingroup Globals
 * \brief Provide a better 'c++' approach for sprintf
 * For example c code is:
 * sprintf(trash, "%04x|%04x", group , elem);
 *
 * c++ code is 
 * std::ostringstream buf;
 * buf << std::right << std::setw(4) << std::setfill('0') << std::hex
 *     << group << "|" << std::right << std::setw(4) << std::setfill('0') 
 *     << std::hex <<  elem;
 * buf.str();
 *
 * gdcm style code is
 * Format("%04x|%04x", group , elem);
 */

std::string Util::Format(const char *format, ...)
{
   char buffer[2048];
   va_list args;
   va_start(args, format);
   vsprintf(buffer, format, args);  //might be a security flaw
   va_end(args); // Each invocation of va_start should be matched 
                 // by a corresponding invocation of va_end
                 // args is then 'undefined'
   return buffer;
}


/**
 * \ingroup Globals
 * \brief Because not available in C++ (?)
 */
void Util::Tokenize (const std::string &str,
                     std::vector<std::string> &tokens,
                     const std::string& delimiters)
{
   std::string::size_type lastPos = str.find_first_not_of(delimiters,0);
   std::string::size_type pos     = str.find_first_of    (delimiters,lastPos);
   while (std::string::npos != pos || std::string::npos != lastPos)
   {
      tokens.push_back(str.substr(lastPos, pos - lastPos));
      lastPos = str.find_first_not_of(delimiters, pos);
      pos     = str.find_first_of    (delimiters, lastPos);
   }
}

/**
 * \ingroup Globals
 * \brief Because not available in C++ (?)
 *        Counts the number of occurences of a substring within a string
 */
 
int Util::CountSubstring (const std::string &str,
                          const std::string &subStr)
{
   int count = 0;   // counts how many times it appears
   std::string::size_type x = 0;       // The index position in the string

   do
   {
      x = str.find(subStr,x);       // Find the substring
      if (x != std::string::npos)   // If present
      {
         count++;                  // increase the count
         x += subStr.length();     // Skip this word
      }
   }
   while (x != std::string::npos);  // Carry on until not present

   return count;
}

/**
 * \ingroup Globals
 * \brief  Weed out a string from the non-printable characters (in order
 *         to avoid corrupting the terminal of invocation when printing)
 * @param s string to remove non printable characters from
 */
std::string Util::CreateCleanString(std::string const &s)
{
   std::string str = s;

   for(unsigned int i=0; i<str.size(); i++)
   {
      if(!isprint((unsigned char)str[i]))
      {
         str[i] = '.';
      }
   }

   if(str.size() > 0)
   {
      if(!isprint((unsigned char)s[str.size()-1]))
      {
         if(s[str.size()-1] == 0)
         {
            str[str.size()-1] = ' ';
         }
      }
   }

   return str;
}

/**
 * \ingroup Globals
 * \brief   Add a SEPARATOR to the end of the name is necessary
 * @param   pathname file/directory name to normalize 
 */
std::string Util::NormalizePath(std::string const &pathname)
{
   const char SEPARATOR_X      = '/';
   const char SEPARATOR_WIN    = '\\';
   const std::string SEPARATOR = "/";
   std::string name = pathname;
   int size = name.size();

   if( name[size-1] != SEPARATOR_X && name[size-1] != SEPARATOR_WIN )
   {
      name += SEPARATOR;
   }
   return name;
}

/**
 * \ingroup Globals
 * \brief   Get the (directory) path from a full path file name
 * @param   fullName file/directory name to extract Path from
 */
std::string Util::GetPath(std::string const &fullName)
{
   std::string res = fullName;
   int pos1 = res.rfind("/");
   int pos2 = res.rfind("\\");
   if( pos1 > pos2)
   {
      res.resize(pos1);
   }
   else
   {
      res.resize(pos2);
   }

   return res;
}

/**
 * \ingroup Util
 * \brief   Get the (last) name of a full path file name
 * @param   fullName file/directory name to extract end name from
 */
std::string Util::GetName(std::string const &fullName)
{   
  std::string filename = fullName;

  std::string::size_type slash_pos = filename.rfind("/");
  std::string::size_type backslash_pos = filename.rfind("\\");
  slash_pos = slash_pos > backslash_pos ? slash_pos : backslash_pos;
  if(slash_pos != std::string::npos)
    {
    return filename.substr(slash_pos + 1);
    }
  else
    {
    return filename;
    }
} 

/**
 * \ingroup Util
 * \brief   Get the current date of the system in a dicom string
 */
std::string Util::GetCurrentDate()
{
    char tmp[512];
    time_t tloc;
    time (&tloc);    
    strftime(tmp,512,"%Y%m%d", localtime(&tloc) );
    return tmp;
}

/**
 * \ingroup Util
 * \brief   Get the current time of the system in a dicom string
 */
std::string Util::GetCurrentTime()
{
    char tmp[512];
    time_t tloc;
    time (&tloc);
    strftime(tmp,512,"%H%M%S", localtime(&tloc) );
    return tmp;  
}

/**
 * \brief Create a /DICOM/ string:
 * It should a of even length (no odd length ever)
 * It can contain as many (if you are reading this from your
 * editor the following character is is backslash followed by zero
 * that needed to be escaped with an extra backslash for doxygen) \\0
 * as you want.
 */
std::string Util::DicomString(const char *s, size_t l)
{
   std::string r(s, s+l);
   gdcmAssertMacro( !(r.size() % 2) ); // == basically 'l' is even
   return r;
}

/**
 * \ingroup Util
 * \brief Create a /DICOM/ string:
 * It should a of even lenght (no odd length ever)
 * It can contain as many (if you are reading this from your
 * editor the following character is is backslash followed by zero
 * that needed to be escaped with an extra backslash for doxygen) \\0
 * as you want.
 * This function is similar to DicomString(const char*), 
 * except it doesn't take a lenght. 
 * It only pad with a null character if length is odd
 */
std::string Util::DicomString(const char *s)
{
   size_t l = strlen(s);
   if( l%2 )
   {
      l++;
   }
   std::string r(s, s+l);
   gdcmAssertMacro( !(r.size() % 2) );
   return r;
}

/**
 * \ingroup Util
 * \brief Safely compare two Dicom String:
 *        - Both string should be of even lenght
 *        - We allow padding of even lenght string by either a null 
 *          character of a space
 */
bool Util::DicomStringEqual(const std::string &s1, const char *s2)
{
  // s2 is the string from the DICOM reference: 'MONOCHROME1'
  std::string s1_even = s1; //Never change input parameter
  std::string s2_even = DicomString( s2 );
  if( s1_even[s1_even.size()-1] == ' ')
  {
    s1_even[s1_even.size()-1] = '\0'; //replace space character by null
  }
  return s1_even == s2_even;
}



/**
 * \ingroup Util
 * \brief   tells us if the processor we are working with is BigEndian or not
 */
bool Util::IsCurrentProcessorBigEndian()
{
#ifdef GDCM_WORDS_BIGENDIAN
   return true;
#else
   return false;
#endif
}



#ifdef _WIN32
typedef BOOL(WINAPI * pSnmpExtensionInit) (
        IN DWORD dwTimeZeroReference,
        OUT HANDLE * hPollForTrapEvent,
        OUT AsnObjectIdentifier * supportedView);

typedef BOOL(WINAPI * pSnmpExtensionTrap) (
        OUT AsnObjectIdentifier * enterprise,
        OUT AsnInteger * genericTrap,
        OUT AsnInteger * specificTrap,
        OUT AsnTimeticks * timeStamp,
        OUT RFC1157VarBindList * variableBindings);

typedef BOOL(WINAPI * pSnmpExtensionQuery) (
        IN BYTE requestType,
        IN OUT RFC1157VarBindList * variableBindings,
        OUT AsnInteger * errorStatus,
        OUT AsnInteger * errorIndex);

typedef BOOL(WINAPI * pSnmpExtensionInitEx) (
        OUT AsnObjectIdentifier * supportedView);
#endif //_WIN32


#ifdef __APPLE__
// Returns an iterator containing the primary (built-in) Ethernet interface. 
// The caller is responsible for releasing the iterator after the caller is 
// done with it.
static kern_return_t FindEthernetInterfaces(io_iterator_t *matchingServices)
{
   kern_return_t   kernResult; 
   mach_port_t     masterPort;
   CFMutableDictionaryRef  matchingDict;
   CFMutableDictionaryRef  propertyMatchDict;
   
   // Retrieve the Mach port used to initiate communication with I/O Kit
   kernResult = IOMasterPort(MACH_PORT_NULL, &masterPort);
   if (KERN_SUCCESS != kernResult)
   {
       printf("IOMasterPort returned %d\n", kernResult);
       return kernResult;
   }
   
   // Ethernet interfaces are instances of class kIOEthernetInterfaceClass. 
   // IOServiceMatching is a convenience function to create a dictionary 
   // with the key kIOProviderClassKey and 
   // the specified value.
   matchingDict = IOServiceMatching(kIOEthernetInterfaceClass);

   // Note that another option here would be:
   // matchingDict = IOBSDMatching("en0");
       
   if (NULL == matchingDict)
   {
       printf("IOServiceMatching returned a NULL dictionary.\n");
   }
   else 
   {
      // Each IONetworkInterface object has a Boolean property with the 
      // key kIOPrimaryInterface. Only the
      // primary (built-in) interface has this property set to TRUE.
      
      // IOServiceGetMatchingServices uses the default matching criteria 
      // defined by IOService. This considers
      // only the following properties plus any family-specific matching 
      // in this order of precedence 
      // (see IOService::passiveMatch):
      //
      // kIOProviderClassKey (IOServiceMatching)
      // kIONameMatchKey (IOServiceNameMatching)
      // kIOPropertyMatchKey
      // kIOPathMatchKey
      // kIOMatchedServiceCountKey
      // family-specific matching
      // kIOBSDNameKey (IOBSDNameMatching)
      // kIOLocationMatchKey
      
      // The IONetworkingFamily does not define any family-specific 
      // matching. This means that in order to have 
      // IOServiceGetMatchingServices consider the kIOPrimaryInterface 
      // property, we must add that property to a separate dictionary and 
      // then add that to our matching dictionary specifying 
      // kIOPropertyMatchKey.
          
      propertyMatchDict = 
         CFDictionaryCreateMutable( kCFAllocatorDefault, 0,
                                    &kCFTypeDictionaryKeyCallBacks,
                                    &kCFTypeDictionaryValueCallBacks);
   
      if (NULL == propertyMatchDict)
      {
          printf("CFDictionaryCreateMutable returned a NULL dictionary.\n");
      }
      else 
      {
         // Set the value in the dictionary of the property with the given 
         // key, or add the key to the dictionary if it doesn't exist. 
         // This call retains the value object passed in.
         CFDictionarySetValue(propertyMatchDict, CFSTR(kIOPrimaryInterface), 
                              kCFBooleanTrue); 
         
         // Now add the dictionary containing the matching value for 
         // kIOPrimaryInterface to our main matching dictionary. This call 
         // will retain propertyMatchDict, so we can release our reference 
         // on propertyMatchDict after adding it to matchingDict.
         CFDictionarySetValue(matchingDict, CFSTR(kIOPropertyMatchKey), 
                              propertyMatchDict);
         CFRelease(propertyMatchDict);
      }
   }

   // IOServiceGetMatchingServices retains the returned iterator, so release
   // the iterator when we're done with it.
   // IOServiceGetMatchingServices also consumes a reference on the matching
   // dictionary so we don't need to release the dictionary explicitly.
   kernResult = 
     IOServiceGetMatchingServices(masterPort, matchingDict, matchingServices);
   if (KERN_SUCCESS != kernResult)
   {
       printf("IOServiceGetMatchingServices returned %d\n", kernResult);
   }

   return kernResult;
}
    
// Given an iterator across a set of Ethernet interfaces, return the MAC 
// address of the last one.
// If no interfaces are found the MAC address is set to an empty string.
// In this sample the iterator should contain just the primary interface.
static kern_return_t GetMACAddress_MAC(io_iterator_t intfIterator, 
                                       UInt8 *MACAddress)
{
   io_object_t   intfService;
   io_object_t   controllerService;
   kern_return_t kernResult = KERN_FAILURE;
   
   // Initialize the returned address
   bzero(MACAddress, kIOEthernetAddressSize);
   
   // IOIteratorNext retains the returned object, so release it when we're 
   // done with it.
   while ( (intfService = IOIteratorNext(intfIterator)))
   {
      CFTypeRef MACAddressAsCFData;        

      // IONetworkControllers can't be found directly by the 
      // IOServiceGetMatchingServices call, since they are hardware nubs 
      // and do not participate in driver matching. In other words,
      // registerService() is never called on them. So we've found the 
      // IONetworkInterface and will 
      // get its parent controller by asking for it specifically.
      
      // IORegistryEntryGetParentEntry retains the returned object, so 
      // release it when we're done with it.
      kernResult = IORegistryEntryGetParentEntry( intfService,
                                                  kIOServicePlane,
                                                  &controllerService );

      if (KERN_SUCCESS != kernResult)
      {
         printf("IORegistryEntryGetParentEntry returned 0x%08x\n", kernResult);
      }
      else
      {
         // Retrieve the MAC address property from the I/O Registry in the 
         // form of a CFData
         MACAddressAsCFData = 
            IORegistryEntryCreateCFProperty( controllerService,
                                             CFSTR(kIOMACAddress),
                                             kCFAllocatorDefault,
                                             0);
         if (MACAddressAsCFData)
         {
            // for display purposes only; output goes to stderr
            //CFShow(MACAddressAsCFData);
            
            // Get the raw bytes of the MAC address from the CFData
            CFDataGetBytes(MACAddressAsCFData, 
                           CFRangeMake(0, kIOEthernetAddressSize), 
                           MACAddress);
            CFRelease(MACAddressAsCFData);
         }

         // Done with the parent Ethernet controller object so we release it.
         (void) IOObjectRelease(controllerService);
      }

      // Done with the Ethernet interface object so we release it.
      (void) IOObjectRelease(intfService);
   }

   return kernResult;
}
#endif

long GetMacAddrSys ( u_char *addr)
{
#ifdef _WIN32
   WSADATA WinsockData;
   if (WSAStartup(MAKEWORD(2, 0), &WinsockData) != 0) 
   {
      std::cerr << "This program requires Winsock 2.x!" << std::endl;
      return -1;
   }

   HANDLE PollForTrapEvent;
   AsnObjectIdentifier SupportedView;
   UINT OID_ifEntryType[] = { 1, 3, 6, 1, 2, 1, 2, 2, 1, 3 };
   UINT OID_ifEntryNum[] = { 1, 3, 6, 1, 2, 1, 2, 1 };
   UINT OID_ipMACEntAddr[] = { 1, 3, 6, 1, 2, 1, 2, 2, 1, 6 };
   AsnObjectIdentifier MIB_ifMACEntAddr = {
       sizeof(OID_ipMACEntAddr) / sizeof(UINT), OID_ipMACEntAddr };
   AsnObjectIdentifier MIB_ifEntryType = {
       sizeof(OID_ifEntryType) / sizeof(UINT), OID_ifEntryType };
   AsnObjectIdentifier MIB_ifEntryNum = {
       sizeof(OID_ifEntryNum) / sizeof(UINT), OID_ifEntryNum };
   RFC1157VarBindList varBindList;
   RFC1157VarBind varBind[2];
   AsnInteger errorStatus;
   AsnInteger errorIndex;
   AsnObjectIdentifier MIB_NULL = { 0, 0 };
   int ret;
   int dtmp;
   int i = 0, j = 0;
   BOOL found = FALSE;

   // Load the SNMP dll and get the addresses of the functions necessary
   HINSTANCE m_hInst = LoadLibrary("inetmib1.dll");
   if (m_hInst < (HINSTANCE) HINSTANCE_ERROR)
   {
      m_hInst = NULL;
      return -1;
   }
   pSnmpExtensionInit m_Init =
       (pSnmpExtensionInit) GetProcAddress(m_hInst, "SnmpExtensionInit");
   pSnmpExtensionInitEx m_InitEx =
       (pSnmpExtensionInitEx) GetProcAddress(m_hInst, "SnmpExtensionInitEx");
   pSnmpExtensionQuery m_Query =
       (pSnmpExtensionQuery) GetProcAddress(m_hInst, "SnmpExtensionQuery");
   pSnmpExtensionTrap m_Trap =
       (pSnmpExtensionTrap) GetProcAddress(m_hInst, "SnmpExtensionTrap");
   m_Init(GetTickCount(), &PollForTrapEvent, &SupportedView);

   /* Initialize the variable list to be retrieved by m_Query */
   varBindList.list = varBind;
   varBind[0].name = MIB_NULL;
   varBind[1].name = MIB_NULL;

   // Copy in the OID to find the number of entries in the
   // Inteface table
   varBindList.len = 1;        // Only retrieving one item
   SNMP_oidcpy(&varBind[0].name, &MIB_ifEntryNum);
   ret = m_Query(ASN_RFC1157_GETNEXTREQUEST, &varBindList, &errorStatus,
                 &errorIndex);
//   printf("# of adapters in this system : %i\n",
//          varBind[0].value.asnValue.number); varBindList.len = 2;

   // Copy in the OID of ifType, the type of interface
   SNMP_oidcpy(&varBind[0].name, &MIB_ifEntryType);

   // Copy in the OID of ifPhysAddress, the address
   SNMP_oidcpy(&varBind[1].name, &MIB_ifMACEntAddr);

   do
   {
      // Submit the query.  Responses will be loaded into varBindList.
      // We can expect this call to succeed a # of times corresponding
      // to the # of adapters reported to be in the system
      ret = m_Query(ASN_RFC1157_GETNEXTREQUEST, &varBindList, &errorStatus,
                    &errorIndex); 
      if (!ret)
      {
         ret = 1;
      }
      else
      {
         // Confirm that the proper type has been returned
         ret = SNMP_oidncmp(&varBind[0].name, &MIB_ifEntryType,
                            MIB_ifEntryType.idLength);
      }
      if (!ret)
      {
         j++;
         dtmp = varBind[0].value.asnValue.number;
         printf("Interface #%i type : %i\n", j, dtmp);

         // Type 6 describes ethernet interfaces
         if (dtmp == 6)
         {
            // Confirm that we have an address here
            ret = SNMP_oidncmp(&varBind[1].name, &MIB_ifMACEntAddr,
                               MIB_ifMACEntAddr.idLength);
            if ( !ret && varBind[1].value.asnValue.address.stream != NULL )
            {
               if ( (varBind[1].value.asnValue.address.stream[0] == 0x44)
                 && (varBind[1].value.asnValue.address.stream[1] == 0x45)
                 && (varBind[1].value.asnValue.address.stream[2] == 0x53)
                 && (varBind[1].value.asnValue.address.stream[3] == 0x54)
                 && (varBind[1].value.asnValue.address.stream[4] == 0x00) )
               {
                   // Ignore all dial-up networking adapters
                   printf("Interface #%i is a DUN adapter\n", j);
                   continue;
               }
               if ( (varBind[1].value.asnValue.address.stream[0] == 0x00)
                 && (varBind[1].value.asnValue.address.stream[1] == 0x00)
                 && (varBind[1].value.asnValue.address.stream[2] == 0x00)
                 && (varBind[1].value.asnValue.address.stream[3] == 0x00)
                 && (varBind[1].value.asnValue.address.stream[4] == 0x00)
                 && (varBind[1].value.asnValue.address.stream[5] == 0x00) )
               {
                  // Ignore NULL addresses returned by other network
                  // interfaces
                  printf("Interface #%i is a NULL address\n", j);
                  continue;
               }
               memcpy( addr, varBind[1].value.asnValue.address.stream, 6);
            }
         }
      }
   } while (!ret);

   // Free the bindings
   SNMP_FreeVarBind(&varBind[0]);
   SNMP_FreeVarBind(&varBind[1]);
   return 0;
#endif //_WIN32

// implementation for GNU/Linux  and cygwin
#if defined(__linux__) || defined(__CYGWIN__)
   struct ifreq ifr;
   struct ifreq *IFR;
   struct ifconf ifc;
   char buf[1024];
   int s, i;
   int ok = 0;

   s = socket(AF_INET, SOCK_DGRAM, 0);
   if (s == -1)
   {
       return -1;
   }

   ifc.ifc_len = sizeof(buf);
   ifc.ifc_buf = buf;
   ioctl(s, SIOCGIFCONF, &ifc);
 
   IFR = ifc.ifc_req;
   for (i = ifc.ifc_len / sizeof(struct ifreq); --i >= 0; IFR++)
   {
      strcpy(ifr.ifr_name, IFR->ifr_name);
      if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0)
      {
         if (! (ifr.ifr_flags & IFF_LOOPBACK))
         {
            if (ioctl(s, SIOCGIFHWADDR, &ifr) == 0)
            {
               ok = 1;
               break;
            }
         }
      }
   }

   close(s);
   if (ok)
   {
      bcopy( ifr.ifr_hwaddr.sa_data, addr, 6);
   }
   else
   {
      return -1;
   }
   return 0;
#endif

// implementation for FreeBSD
#ifdef __FreeBSD__
   struct ifaddrs *ifap, *ifaphead;
   int rtnerr;
   const struct sockaddr_dl *sdl;
   caddr_t ap;
   int alen;
 
   rtnerr = getifaddrs(&ifaphead);
   if (rtnerr)
   {
     //perror(NULL);
     return -1;
   }
 
   for (ifap = ifaphead; ifap; ifap = ifap->ifa_next)
   {
      if (ifap->ifa_addr->sa_family == AF_LINK)
      {
         sdl = (const struct sockaddr_dl *) ifap->ifa_addr;
         ap = ((caddr_t)((sdl)->sdl_data + (sdl)->sdl_nlen));
         alen = sdl->sdl_alen;
         if (ap && alen > 0) 
         {
            //int i;
 
            //printf ("%s:", ifap->ifa_name);
            //for (i = 0; i < alen; i++, ap++)
              {
              //printf("%c%02x", i > 0 ? ':' : ' ', 0xff&*ap);
              }
            bcopy( ap, addr, 6);
            //putchar('\n');
         }
      }
   }
   //putchar('\n');
 
   freeifaddrs(ifaphead);
   return 0;
#endif //FreeBSD

// implementation for HP-UX
#ifdef __HP_aCC
   const char LAN_DEV0[] = "/dev/lan0";

   int fd;
   struct fis iocnt_block;
   char net_buf[sizeof(LAN_DEV0)+1];

   (void)sprintf(net_buf, "%s", LAN_DEV0);
   char *p = net_buf + strlen(net_buf) - 1;

   // 
   // Get 802.3 address from card by opening the driver and interrogating it.
   //
   for (int i = 0; i < 10; i++, (*p)++)
   {
      if ((fd = open (net_buf, O_RDONLY)) != -1) 
      {
         iocnt_block.reqtype = LOCAL_ADDRESS;
         ioctl (fd, NETSTAT, &iocnt_block);
         close (fd);

         if (iocnt_block.vtype == 6) break;
      }
   }

   if (fd == -1 || iocnt_block.vtype != 6)
   {
      return -1;
   }

   bcopy( &iocnt_block.value.s[0], addr, 6);
   return 0;
#endif // HP-UX

/* implementation for AIX */
#ifdef _AIX
   int size = getkerninfo(KINFO_NDD, 0, 0, 0);
   if (size <= 0)
   {
      return -1;
   }
   struct kinfo_ndd *nddp = (struct kinfo_ndd *)malloc(size);
         
   if (!nddp)
   {
      return -1;
   }
   if (getkerninfo(KINFO_NDD, nddp, &size, 0) < 0)
   {
      free(nddp);
      return -1;
   }
   bcopy(nddp->ndd_addr, addr, 6);
   free(nddp);

   return 0;
#endif //_AIX

#ifdef __APPLE__
   io_iterator_t intfIterator;
   UInt8 MACAddress[ kIOEthernetAddressSize ];
 
   kern_return_t kernResult = FindEthernetInterfaces(&intfIterator);
   
   if (KERN_SUCCESS != kernResult)
   {
       printf("FindEthernetInterfaces returned 0x%08x\n", kernResult);
   }
   else
   {
      kernResult = GetMACAddress_MAC(intfIterator, MACAddress);

      if (KERN_SUCCESS != kernResult)
      {
          printf("GetMACAddress returned 0x%08x\n", kernResult);
      }
   }

   (void) IOObjectRelease(intfIterator); // Release the iterator.
       
   memcpy(addr, MACAddress, kIOEthernetAddressSize);
   return kernResult;
#endif //APPLE

/* Not implemented platforms */
  memset(addr,0,6);
  return -1;
}

std::string Util::GetMACAddress()
{
   // This is a rip from: http://cplus.kompf.de/macaddr.html for Linux/CYGWIN, HPUX and AIX 
   // and http://tangentsoft.net/wskfaq/examples/src/snmpmac.cpp for windows version
   // and http://groups-beta.google.com/group/sol.lists.freebsd.hackers/msg/0d0f862e05fce6c0 for the FreeBSD version
   // and http://developer.apple.com/samplecode/GetPrimaryMACAddress/GetPrimaryMACAddress.html for MacOSX version
   u_char addr[6];
   std::string macaddr;
 
   long stat = GetMacAddrSys(addr);
   if (0 == stat)
   {
      //printf( "MAC address = ");
      for (int i=0; i<6; ++i) 
      {
         //printf("%2.2x", addr[i]);
         macaddr += Format("%2.2x", addr[i]);
      }
      // printf( "\n");
      return macaddr;
   }
   else
   {
      //printf( "No MAC address !\n" );
      return "";
   }
}

/**
 * \ingroup Util
 * \brief   Return the IP adress of the machine writting the DICOM image
 */
std::string Util::GetIPAddress()
{
  // This is a rip from 
  // http://www.codeguru.com/Cpp/I-N/internet/network/article.php/c3445/
#ifndef HOST_NAME_MAX
  // SUSv2 guarantees that `Host names are limited to 255 bytes'.
  // POSIX 1003.1-2001 guarantees that `Host names (not including the
  // terminating NUL) are limited to HOST_NAME_MAX bytes'.
#  define HOST_NAME_MAX 255
  // In this case we should maybe check the string was not truncated.
  // But I don't known how to check that...
#if defined(_MSC_VER) || defined(__BORLANDC__)
  // with WinSock DLL we need to initialise the WinSock before using gethostname
  WORD wVersionRequested = MAKEWORD(1,0);
  WSADATA WSAData;
  int err = WSAStartup(wVersionRequested,&WSAData);
  if (err != 0)
  {
      // Tell the user that we could not find a usable
      // WinSock DLL.
      WSACleanup();
      return "127.0.0.1";
  }
#endif
  
#endif //HOST_NAME_MAX

  std::string str;
  char szHostName[HOST_NAME_MAX+1];
  int r = gethostname(szHostName, HOST_NAME_MAX);

  if( r == 0 )
  {
    // Get host adresses
    struct hostent *pHost = gethostbyname(szHostName);

    for( int i = 0; pHost!= NULL && pHost->h_addr_list[i]!= NULL; i++ )
    {
      for( int j = 0; j<pHost->h_length; j++ )
      {
        if( j > 0 ) str += ".";

        str += Util::Format("%u", 
            (unsigned int)((unsigned char*)pHost->h_addr_list[i])[j]);
      }
      // str now contains one local IP address 

#if defined(_MSC_VER) || defined(__BORLANDC__)
  WSACleanup();
#endif
  
    }
  }
  // If an error occur r == -1
  // Most of the time it will return 127.0.0.1...
  return str;
}

/**
 * \ingroup Util
 * \brief Creates a new UID. As stipulate in the DICOM ref
 *        each time a DICOM image is create it should have 
 *        a unique identifier (URI)
 */
std::string Util::CreateUniqueUID(const std::string &root)
{
  // The code works as follow:
  // echo "gdcm" | od -b
  // 0000000 147 144 143 155 012
  // Therefore we return
  // radical + 147.144.143.155 + IP + time()
  std::string radical = root;
  if( !root.size() ) //anything better ?
  {
    radical = "0.0."; // Is this really usefull ?
  }
  // else
  // A root was specified use it to forge our new UID:
  radical += "147.144.143.155"; // gdcm
  radical += ".";
  radical += Util::GetIPAddress();
  radical += ".";
  radical += Util::GetCurrentDate();
  radical += ".";
  radical += Util::GetCurrentTime();

  return radical;
}

template <class T>
std::ostream &binary_write(std::ostream &os, const T &val)
{
    return os.write(reinterpret_cast<const char*>(&val), sizeof val);
}

std::ostream &binary_write(std::ostream &os, const uint16_t &val)
{
#ifdef GDCM_WORDS_BIGENDIAN
    uint16_t swap;
    swap = ((( val << 8 ) & 0x0ff00 ) | (( val >> 8 ) & 0x00ff ) );
    return os.write(reinterpret_cast<const char*>(&swap), 2);
#else
    return os.write(reinterpret_cast<const char*>(&val), 2);
#endif //GDCM_WORDS_BIGENDIAN
}

std::ostream &binary_write(std::ostream &os, const uint32_t &val)
{
#ifdef GDCM_WORDS_BIGENDIAN
    uint32_t swap;
    swap = ( ((val<<24) & 0xff000000) | ((val<<8)  & 0x00ff0000) | 
             ((val>>8)  & 0x0000ff00) | ((val>>24) & 0x000000ff) );
    return os.write(reinterpret_cast<const char*>(&swap), 4);
#else
    return os.write(reinterpret_cast<const char*>(&val), 4);
#endif //GDCM_WORDS_BIGENDIAN
}

std::ostream &binary_write(std::ostream &os, const char *val)
{
    return os.write(val, strlen(val));
}

std::ostream &binary_write(std::ostream &os, std::string const &val)
{
    return os.write(val.c_str(), val.size());
}

} // end namespace gdcm