# File lib/logging/appenders/file.rb, line 25 def self.assert_valid_logfile( fn ) if ::File.exist?(fn) if not ::File.file?(fn) raise ArgumentError, "#{fn} is not a regular file" elsif not ::File.writable?(fn) raise ArgumentError, "#{fn} is not writeable" end elsif not ::File.writable?(::File.dirname(fn)) raise ArgumentError, "#{::File.dirname(fn)} is not writable" end true end