How to add a string from variables to each line in a file in BASH

Question

I have this one :

sed -e 's/$/string after each line/' -i filename

but i want instead of "string after each line"
have a string from the following result:

cat filename2 | tr '\n' ' '

what should I do?

Answer 1

If I understand you correctly, you can just save this string in a variable like so:

$ myvar=`cat filename2 | tr '\n' ' '`; sed -e "s/$/ $myvar/" -i filename

Basically, you store the value of the command inside myvar . Then, you run sed and provide the contents of $myvar as a string for the s (substitute) command.