$sop = xx 
#$sop read from user input
#$sop is <,>,>=,<=,==,!=
$sport = xx 
#$sport read from user input
#$sport is tcp or udp port 
$code = "if($port_a $op $port_b ){";
$code .= "$result =1;}";
$code .= "else{$result=0;}";
while(<FH>)
{
 @tmpdata = split /:/;
 $port_a = $tmpdata[8];
 $op = $sop;
 $port_b = $sport;
 eval $code;
 if ($result)
 {
  #do something
 }
 else
 {
  #do something
 }
}
But perl don't support that . So I must use like that:
while(<FH>)
{
 @tmpdata = split /:/;
 if ( ($sop eq "<") and ($tmpdata[8]<$sport ) )
 {
  #do something
 }
 elsif( ($sop eq ">") and ($tmpdata[8]>$sport )
 {
  #do something
 }
 #and other op like <=,>=,==,!=
}