# Example usage 1:
awk 'NR==FNR { b[$0] = 1; next } !b[$0]' input_file_1 input_file_2
# Where:
#	- this returns all lines of input_file_2 that aren't found in input_file_1
# Note, remove the ! to return all lines in common between the files
# Example usage 2:
comm -23 input_file_1 input_file_2
# Where:
#	- this returns lines only found in input_file_1
comm -13 input_file_1 input_file_2
# Where:
#	- this returns lines only found in input_file_2
comm -12 input_file_1 input_file_2
# Where:
#	- this returns lines found in both input files