How to find and replace all occurrences of a string recursively in a directory tree? [duplicate]

Question

Using just grep and sed, how do I replace all occurrences of:

a.example.com 

with

b.example.com 

within a text file under the /home/user/ directory tree recursively finding and replacing all occurrences in all files in sub-directories as well.

Answer 1

Try this:

find /home/user/ -type f | xargs sed -i  's/a\.example\.com/b.example.com/g' 

In case you want to ignore dot directories

find . \( ! -regex '.*/\..*' \) -type f | xargs sed -i 's/a\.example\.com/b.example.com/g' 

Edit: escaped dots in search expression

Answer 2

Try this:

grep -rl 'SearchString' ./ | xargs sed -i 's/REPLACESTRING/WITHTHIS/g' 

grep -rl will recursively search for the SEARCHSTRING in the directories ./ and will replace the strings using sed.

Ex:

Replacing a name TOM with JERRY using search string as SWATKATS in directory CARTOONNETWORK

grep -rl 'SWATKATS' CARTOONNETWORK/ | xargs sed -i 's/TOM/JERRY/g' 

This will replace TOM with JERRY in all the files and subdirectories under CARTOONNETWORK wherever it finds the string SWATKATS.