+ def extension_name
+ filetype = `file -bz #{trace_name}`.chomp
+ gzipped = filetype =~ /gzip compressed/
+ bzipped = filetype =~ /bzip2 compressed/
+ zipped = filetype =~ /Zip archive/
+ tarred = filetype =~ /tar archive/
+
+ if tarred and gzipped then
+ extension = ".tar.gz"
+ elsif tarred and bzipped then
+ extension = ".tar.bz2"
+ elsif tarred
+ extension = ".tar"
+ elsif gzipped
+ extension = ".gpx.gz"
+ elsif bzipped
+ extension = ".gpx.bz2"
+ elsif zipped
+ extension = ".zip"
+ else
+ extension = ".gpx"
+ end
+
+ return extension
+ end
+