[fpc-pascal] lNet getting the local IP

[Brian Winfrey]

I don't know if you noticed, but it appears that code has some
depracated properties that should be changed.

Here are the modifications I made in exploring this issue:

program GetPrimaryIpAddress;
{$mode objfpc}

uses
  baseunix,
  unixtype,
  sockets,
  SysUtils;

procedure Get(out AddrOut: string);
const
  CN_GDNS_ADDR = '127.0.0.1';
  CN_GDNS_PORT = 53;
var
  sock: longint;
  err: longint;
  UnixAddr: TInetSockAddr;
  HostAddr: TSockAddr;
  len: Integer;
begin
  err := 0;

  sock := fpsocket(AF_INET, SOCK_DGRAM, 0);
  assert(sock <> -1);

// changed because previous properties were deprecated
  UnixAddr.sin_family := AF_INET;
  UnixAddr.sin_port := htons(CN_GDNS_PORT);
  UnixAddr.sin_addr := StrToHostAddr(CN_GDNS_ADDR);

  if (fpConnect(sock, @UnixAddr, SizeOf(UnixAddr)) = 0) then
  begin
    try
      len := SizeOf(HostAddr);
      if (fpgetsockname(sock, @HostAddr, @len) = 0) then
      begin
        AddrOut := NetAddrToStr(HostAddr.sin_addr);
      end
      else
      begin
        err:=socketError;
      end;
    finally
      if (fpclose(sock) <> 0) then
      begin
        err := socketError;
      end;
    end;
  end
  else
  begin
    err:=socketError;
  end;

  if (err <> 0) then
  begin
    // report error
  end;
end;

var
  strAddr: string;

begin
  Get(strAddr);
  WriteLn('ip : ',strAddr);
end.