Search and replace with sed when dots and underscores are present

Question

How do I replace foo. with foo_ with sed simply running

sed \'s/foo./foo_/g\' file.php

doesn\'t work. Thanks!

Answer 1

For myself, sed 's/foo\./foo_/g' is working. But you can also try:

sed -e 's/foo\./foo_/g'

and

sed -e "s/foo\\./foo_/g"

and

sed 's/foo[.]/foo_/g'