regex - Why is sed not recognizing as a tab?

Question

sed "s/(.*)/1/" $filename > $sedTmpFile && mv $sedTmpFile $filename

I am expecting this sed script to insert a tab in front of every line in $filename however it is not. For some reason it is inserting a t instead.

Answer 1

Not all versions of sed understand . Just insert a literal tab instead (press Ctrl-V then Tab).