There are a number of ways to compare files and directories on Linux systems. The diff, colordiff, and wdiff commands are just a sampling of commands that you’re likely to run into. Another is comm. The command (think “common”) lets you compare files in side-by-side columns the contents of individual files.
Where diff gives you a display like this showing the lines that are different and the location of the differences, comm offers some different options with a focus on common content. Let’s look at the default output and then some other features.
Here’s some diff output — displaying the lines that are different in the two files and using < and > signs to indicate which file each line came from.
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