Bash script: Appending text at the last character of specific line of a file

Question

I am trying to append a variable at the last character of a specific line of a file from a bash script.

The file is called myfile.txt and what I want to

Answer 1

Try

sed -e "s/^MYVERSION=/MYVERSION=.*$/&${VERSION}/g" < myfile.txt

The command appends the value of VERSION to the line with 'MYVERSION='

Answer 2

Try this:

sed -i "/^MYVERSION=/ s/\$/$VERSION/" myfile.txt

The idea is that it finds a line that starts with MYVERSION= and then replaces the end of that line with the contents of the $VERSION environment variable.

Edit: originally I wasn't sure if the first $ needed to be escaped, but @sehe's comment and its upvoters convinced me that it does.