find . -name '*.php' -exec sed -i -e"s#search#replace#g" {} \;

Find the files you want, run sed on each one of them, edit inline with the included expression, done.

Big thing to note is sed using ‘#’ for a seperator and not ‘/’ . I believe the man page still talks about using a forward slash, but ‘#’ works.

The results from your find command are run through the {} so don’t forget that, and a find -exec must be terminated with a \;

Enjoy.