function uncompress (dest : pBytef;
                     var destLen : uLong;
                     const source : array of byte;
                     sourceLen : uLong) : int;
var
  stream : z_stream;
  err : int;
begin
  stream.next_in := pBytef(@source);
  stream.avail_in := uInt(sourceLen);
  { Check for source > 64K on 16-bit machine: }
  if (uLong(stream.avail_in) <> sourceLen) then
  begin
    uncompress := Z_BUF_ERROR;
    exit;
  end;

  stream.next_out := dest;
  stream.avail_out := uInt(destLen);
  if (uLong(stream.avail_out) <> destLen) then
  begin
    uncompress := Z_BUF_ERROR;
    exit;
  end;

  stream.zalloc := NIL;       { alloc_func(0); }
  stream.zfree := NIL;        { free_func(0); }

  err := inflateInit(stream);
  if (err <> Z_OK) then
  begin
    uncompress := err;
    exit;
  end;

  err := inflate(stream, Z_FINISH);
  if (err <> Z_STREAM_END) then
  begin
    inflateEnd(stream);
    if err = Z_OK then
      uncompress := Z_BUF_ERROR
    else
      uncompress := err;
    exit;
  end;
  destLen := stream.total_out;

  err := inflateEnd(stream);
  uncompress := err;
end;

 $fp = fopen( '2.txt', "r" );
  $data = fread ( $fp, filesize( '2.txt' ) );
  fclose( $fp );

   zlib_encode($output,$data,-1);

  echo $output;