How to replace multiple strings using sed?
If you have multiple strings to replace, you can either using the "-e" option in sed, e.g.
sed -e 's/a/A/' -e 's/b/B/' < old.txt > new.txt
or, you can use a sed script file to store all the replace conditions
e.g. vi replace.sed
and execute like
sed -f replace.sed < old.txt > new.txt