On Fri, Aug 21, 2020 at 02:35:35PM -0400, Greg Wooledge wrote: > No. Use $'...' instead of '...'. > > sed '/line1/{N;N;a line-to-add\n}' input-file Crap. Of course I meant to write sed $'/line1/{N;N;a line-to-add\n}' input-file