Text Processing: Recursive search and replace
From WikiMLT
grep -rni 'string or regexp' *
Where:
*– will match to all files and directories (which doesn't start with., alternatively you may need to use./to match everything within the current directory;-r,--recursive– in this case works together with*(or./);-n, –line-number – output the line number where the match is found,-i,--ignore-case– do case insensitive match.