Find and replace in directory on the shell

find_and_replace.sh

# example: replacing :mocha with :rspec as mock framework

find . -name '*_spec.rb' -exec sed -i.old -e 's/returns/and_return/' {} \;
find . -name '*_spec.rb' -exec sed -i.old -e 's/expects/should_receive/' {} \;
find . -name '*_spec.rb' -exec sed -i.old -e 's/stubs/stub/' {} \;
find . -name '*.old' -exec rm {} \;

Totally forgot you can do this:

find . -name '*_spec.rb' -exec sed -i.old \ 
  -e 's/returns/and_return/' \
  -e 's/expects/should_receive/' \
  -e 's/stubs/stub/' {} \;
find . -name '*.old' -exec rm {} \;

sed can take multiple commands — expressions — when you prepend them with the -e switch. I’ve gotten myself in the habit of specifying that for sed and grep.