###########################
##
##  $input contains the necessary parameters for the external executable file and the output is generated into output_file created
##
###########################

`some_external_excutable_file $input >output_file`

open (OUTPUT,"output_file");
@output=<OUTPUT>;
close OUTPUT;

############################
##
##  I read the output file into an array and use the array for my further analysis
##
############################