Simple bash script checks http 200 response code for urls from file

script.sh

#!/bin/bash

## This script simply gets a line (with url) from 
## the file setted as parameter and checks its url 
## response code
##
## example: ./script.sh urls.txt
##
## https://github.com/aozimkov
##
## *************************************************

checker(){
RESPONSE_CODE=$(curl --write-out %{http_code} --silent --output /dev/null $1)
CODENUM=$2
if [ "$RESPONSE_CODE" != "$CODENUM" ]; then
  echo "$LINE : $CODENUM"
fi
}

if [ -z $2 ];
then
  CODE=$2
else
  CODE=200
fi

while read LINE; do checker "$LINE" "$CODE"; done < $1