Task: Print all unique file paths under "testbed/dir1" compared to "testbed/dir2"
Command: comm -23 <(find /testbed/dir1 | sed 's#/testbed/dir1/##' | sort) <(find /testbed/dir2 | sed 's#/testbed/dir2/##' | sort) | sed 's#^#/testbed/dir1/#'
Equivalent command: comm -23 <(find testbed/dir1 -type f | sed 's|testbed/dir1/||' | sort) <(find testbed/dir2 -type f | sed 's|testbed/dir2/||' | sort) | sed 's|^|testbed/dir1/|'