Example of Find and Replace String in Files with SED

SED ( Stream Editor ) tool is designed for find and replace strings or words in a text file. Its very useful like you need to change any word in multiple files and you don’t want to do it manually because of its time killing.

Replace String in Single file in Place

Below example command will find all occurances of string “Hello” and replace with “Howdy” in place ( in same file ) in file name /opt/docs/welcome.txt.

# sed -i 's/Hello/Howdy/g' /opt/docs/welcome.txt

Old version sed command does not support in place editing of files.

Replace String in all file in a Directory

Following command if helpful if you need to replace string in multiple files at once in a directory ( /opt/docs/ )

# find /opt/docs/ -type f -exec sed -i 's/Hello/Howdy/g' {} ;

Replace String in Single file but Keep Original

If you do not want to make changes in your original file and create new files with changed strings, use following command.

# sed 's/Hello/Howdy/g' /opt/docs/welcome.txt > /opt/docs/welcome_2.txt