helm/bin/replace.sh

#!/bin/sh
#
# Find and replace by a given list of files.
#
# replace foo bar **/*.rb

find_this="$1"; shift
replace_with="$1"; shift

items=( $(ag -l --nocolor "$find_this" "$@") )
temp="${TMPDIR:-/tmp}/replace_tmp.$$"
for item in ${items[@]}; do
  sed "s/$find_this/$replace_with/g" "$item" > "$temp" && mv "$temp" "$item"
done