FileMagic is a Ruby binding to the magic(4) library, which you may know better as the file(1) command. The file command identifies the type of a file using, among other tests, a test for whether the file begins with a certain magic number.
These details are provided for information only. No information here is legal advice and should not be used as such.
At one point, Open Hub analyzed source code for this project based on code location(s) available at that time. Since then, the code locations have been removed.