Open Midi File with Different Extension [SOLVED]

[MusoBob]

I just want to open song.seq that is a midi file with an .seq extension.
Can I do this without doing a shell copy command
cp song.seq song.mid

[MusoBob]

I think I will just read and write it to a midi file

This works and I get
Song.seq.mid
but I would like Song seq.mid
if I do a gsub on source_filename then file:write(source_content) don't work.

retval, source_filename = reaper.GetUserFileNameForRead("", "Choose SEQ File", "seq")
file = io.open(source_filename, "rb")
source_content = file:read("*all")
file = io.open(source_filename ..".mid", "wb")
file:write(source_content)
file:close()

[MusoBob]

This did it

retval, source_filename = reaper.GetUserFileNameForRead("", "Choose SEQ File", "seq")
file = io.open(source_filename, "rb")
source_content = file:read("*all")
source_filename = string.gsub(source_filename, ".seq$", " seq .mid")
file = io.open(source_filename", "wb")
file:write(source_content)
file:close()