There's nothing inherently wrong with the glob approach you're using with the <> operator. The POD does warn against variable interpolation within a <> operator for readability reasons (perlop section on the < > operator):

If you're trying to do variable interpolation, it's definitely better to use the glob() function, because the older notation can cause people to become confused with the indirect filehandle notation.

    @files = glob("$dir/*.[ch]");
    @files = glob($files[$i]);
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Seems like a pretty minor nit. It sounds like you're fine.