linux sed all files code example

Example 1: find and replace in all files in directory centos

grep -rl 'apples' /dir_to_search_under | xargs sed -i 's/apples/oranges/g'

Example 2: sed replace all occurances?

echo dog dog dos | sed -e 's:dog:log:g'

#You can also use the above answer with appropriate slashes like
echo "grepper is a nice grepper" | sed "s/grepper/blow/g"