I have a file that looks something like this: ABC DEF GHI I have a shell variable that looks something like this: var="MRD" What I want to do, is to make my file look like this: ABC MRD DEF GHI I was trying to do this: sed -i -e 's/ABC/&$var/g' text.txt but it only inserts $var instead of the value. I also tried this: sed -i -e 's/ABC/&"$var"/g' text.txt but that didn't work either. Any thoughts? Thanks!