Just had a situation where I need to find and replace a value in multiple html, js, php files starting in /var/www/html and descending to replace all instances.

This worked for me.

fgrep srv-02 * -lR | xargs sed -i.bak -e 's/srv-02/srv-04/g'

Basically the above means use fgrep to get a list of files which contain a match

Use xargs to pass each filename to sed

sed creates a backup of each file with a '.bak' extension and does a global (g) find and replace on the search term