How to add quote at the end of line by SED

Question

sed -i 's/$/'/g' 
sed -i "s/$/'/g"

How to escape both $ and ' by 1 command?

Answer 1

This might work for you (GNU sed):

sed 's/$/'''/' file

Adds a single quote to the end of a line.

sed 's/$/'''/' file

Replaces a $ by a single quote.

sed 's/$$/'''/' file

Replaces a $ at the end of line by a single quote.

N.B. Surrounding sed commands by double quotes is fine for some interpolation but may return unexpected results.