Run diff on set of files which possibly changed over time

diff_series

#!/bin/bash

if [[ $# -lt 2 ]]; then
    echo "$0 <file1> <file2> <file3> [file4]"
    echo "This script is meant to run on 3 or more files, to see the changes over time."
    exit 1
fi

while [[ $# -ge 2 ]]; do
    TEST=$(diff -q $1 $2)
    if [ -n "$TEST" ]; then
        echo ""
        echo "$2"
        diff $1 $2
    fi
    shift
done

My use case was a set of XML files which were uploaded by a 3rd party service multiple times a day, regardless of whether the data changed. Using this, I was able to figure out which files had changes, and what those specific changes were.