Find and replace a word from all the files in a directory

This tip make use of powerful command “sed”. Run this command to locate and substitute a specific word within all the files in the current directory, whether they have a .txt, .cfg, .js, .html extension, or any other file type that suits your needs. You can find sed command in most of the linux systems. But if you are on windows, follow this - Chocolatey The Package Manager for Windows

sed -i -- 's/firstword/secondword/g' *.txt

It searches for the text “firstword” in all the .txt files in the current direcory and replaces it with “secondword”.