Command

$ grep -ilr "sourceString" * | xargs -I@ sed -i '' 's/sourceString/targetString/g' @

description

grep – file pattern searcher

from OSX grep man page

• -i: --ignore-case Perform case insensitive matching
• -l: --files-with-matches Only the names of files containing selected lines are written to standard output.
• -r: -R, --recursive Recursively search subdirectories.

xargs – construct arguments list(s) and execute utility

from OSX xargs man page

• -I@ ** @:

sed – stream editor

from OSX man page

• -i '': specify backup extension. 0 length backup extension meaning no backup
• 's/sourceString/targetString/g' : search and replace globally all occurences of sourceString by targetString