sed – replace text in multiple files

sed – is useful to find and replace text in single multiple files.

• Replacing foo with foo_bar in a single file.
  
  
sed -i 's/foo/foo_bar/g' somefile.module
• -i = tell sed to edit the file(s)
• s = substitute the following text
• foo = what you want to substitute
• foo_bar = what you want to replace
• g = global, match all occurrences in the line