New to sed/awk.. reading a book on them. Trying to convert: ### Text Text Text to ###<tab>Text Text Text or Text Text Text So far I have /^[^0-9]/d #deletes any lines that do not start with a number Then for the actual replace tried several unsucesfull tries such as s/^[0-9][0-9]* */^[0-9][0-9]* */<tab>/ s/^[0-9][0-9]* */ /<tab> / Any suggestions?