Gethostbyaddr

I have an RPG program I copied from Midrange (thank you Scott Klement ) using 
the gethostbyaddr API and it worked well on my W2k machines.  I have upgraded 
my machines to XP and the program no longer returns the host name.  I have the 
latest patches applied (06/18/2003).
 
Jon Giles
 
hdebug dftactgrp( *no ) bnddir( 'QC2LE' )                         
Dinet_addr        PR            10U 0 ExtProc('inet_addr')        
D  IPAddr                         *   Value options(*string)      
                                                                  
DGetHostByAddr    PR              *   ExtProc('gethostbyaddr')    
D  HostEnt                      10U 0                             
D  AddrLen                      10I 0 Value                       
D  AddrType                     10I 0 Value                       
                                                                  
DHostEntP         S               *                               
                                                                  
Dhostent          DS                   Based(HostEntP)            
D  h_name                         *                               
D  h_aliases                      *                               
D  h_addrtype                    5I 0                             
D  h_length                      5I 0                             
D  h_addr_list                    *                               
                                                                  
DIP32Addr         S             10U 0                             
DAF_INET          C                   Const(2)                    
C     *Entry        PList                                              
C                   Parm                    P#IPAddress      15        
C                   Parm                    P#IPName         64        
                                                                       
 * Convert IP to binary format:                                        
C                   Eval      IP32Addr  =  inet_addr(P#IPAddress)      
                                                                       
 * do reverse DNS lookup:                                              
                                                                       
C                   Eval      HostEntP = gethostbyaddr(IP32Addr :      
C                                                     %size(IP32Addr) :
C                                                     AF_INET)         
                                                                       
 * set results                                                         
                                                                       
C                   if        HostEntP  = *Null                        
C                   Eval      P#IPName  = 'Host not found!'            
C                   Else                                               
C                   Eval      P#IPName  = %str(h_name)                 
C                   endif                                              
C                   SetOn                                        Lr  
C                   Return