UNIX for Beginners Questions & Answers

awk 'FNR==NR{                  ###This condition will be TRUE when first file named file1 is being read.
                q=$2;          ###creating variable named q whose value is $2(second field) of current line.
                $1=$2="";      ###Nullifying first and second fields now in a current line.
                A[q]=$0;       ###Creating array named A whose index is variable q and value is current line.
                next           ###next is awk built-in keyword and it will skip all next statement.
            }
    ($3 in A){                 ###Traversing through array A with $3, if $3 comes in array A then do following.
                print $0,A[$3] ###printing the current line and array A value with index $3 of it.
             }
    ' file1  file2             ###Mentioning the Input_files file1 and file2 here.