How to find out the IP(s) of your machine

Hello list,

what's the easiest way to find out the IP address(es) of your local
machine (as a string value)?

I've found an incredibly complex way (at least incredible for me) to do
this and I cannot imagine that there is not something simpler:

  string getMyIP() const throw(PRException)
  {
    const int HOSTLEN = 255;
    char hostname[HOSTLEN];
    char hostbuffer[PR_NETDB_BUF_SIZE];
    PRHostEnt hostent;
    PRNetAddr hostaddress;
    const PRUint32 IPBUFFERSIZE = 20; /* aaa.bbb.ccc.ddd\0 */
    char hostIPbuffer[IPBUFFERSIZE];

    if( PR_GetSystemInfo(PR_SI_HOSTNAME, hostname, HOSTLEN) != PR_SUCCESS )
      throw PRException("PR_GetSystemInfo() in getMyIP()");

    if( PR_GetHostByName( hostname, hostbuffer, PR_NETDB_BUF_SIZE,
&hostent )
        != PR_SUCCESS )
      throw PRException("PR_GetHostByName() in getMyIP()");

    if( PR_EnumerateHostEnt(0, &hostent, 0, &hostaddress) == -1 )
      throw PRException("PR_EnumerateHostEnt() in getMyIP()");

    if( PR_NetAddrToString( &hostaddress, hostIPbuffer, IPBUFFERSIZE )
        != PR_SUCCESS )
      throw PRException("PR_NetAddrToString() in getMyIP()");

    return string( hostIPbuffer );
  }

Joachim