bash vlookup function

# Example usage:
awk 'FNR==NR{a[$1]=$2; next}; {if($9 in a) {print $0, "\t"a[$9];} else {print $0, "\tNA"}}' input_file_1 input_file_2
# This command does a VLOOKUP-type operation between two files using
#	awk. With the numbers above, column 1 from input_file_1 is used 
#	an a key in an array with column 2 of input_file_1 as the match for 
#	the key. Column 9 of input_file_2 is then compared to the keys from
#	input_file_1 and any matches return the associated match from 
#	input_file_1 (here, column 2).