Linux Shell Scripting Cookbook - Third Edition

How to do it...

Note that comm takes two sorted files as input. Here are our sample input files:

$ cat A.txt
apple
orange
gold
silver
steel
iron

$ cat B.txt
orange
gold
cookies
carrot

$ sort A.txt -o A.txt ; sort B.txt -o B.txt

1. First, execute comm without any options:

        $ comm A.txt B.txt 
        apple
                carrot
                cookies
                        gold
        iron
                        orange
        silver
        steel

 The first column of the output contains lines that are only in A.txt. The second column contains lines that are only in B.txt. The third column contains the common lines from A.txt and B.txt. Each of the columns are delimited using the tab (\t) character.

2. In order to print the intersection of two files, we need to remove the first and second columns and print the third column. The -1 option ...