Ubuntu Unleashed 2013 Edition: Covering 12.10 and 13.04, Eighth Edition

Finding Similarities in Files with comm

The comm command compares files line by line and outputs any lines that are identical. For example:

matthew@seymour:~$ comm file1 file2

This command output displays in three columns: column 1 shows lines only in file1, column2 shows every line only in file2, and column 3 shows every line that is the same between the two files. This is a much more detailed comparison than with diff, and the output can be overwhelming when all you want is to find or check for one or two simple changes. However, it can be incredibly useful when you aren’t terribly familiar with either file and want to see how they compare.

There are fewer options available when running comm. These three are the ones you are most likely to ...