Use Perl to only print if value of column A is present for each value in Column B : So in Perl how can I go through a sample file like so:

    1 D Z
    1 E F
    1 G L 
    2 D I
    2 E L
    3 D P
    3 G L

So here I want to be able to print out only the values that have the same first value across all values in the second column. Thus output would look like this:

    1 D Z
    1 E F
    1 G L 


