The input file contains a starting and ending string, so I am using a regular expression to extract group $2 which is what is between SUBBEGIN and SUBEND. I then split $2 based on the equals sign to create my hash %hash.Then within the while loop and using two separate if statements I use the hash function exists to check if key1 is in the %hash(first if statment) and if key2 is in the %hash (second if statement)