AG is pretty rad

One of the most indispensible tools in my toolbox is ag. It is really efficient at splunking through tons of files super fast.

It can anwser questions like:

• Where is this function used
• Which files do something similar
• Which files are named like this
• Does anything match this regular expression

Tips

Before/After

By default ag shows just the matches line, often you want to see lines before and after. ag has the options -B/--before or -A/--after for that.

# show 5 lines before and 5 lines after
ag all-the-things -A 5 -B 5

Find filename by pattern

If you want to find all files where the name matches a pattern, you can use the -g option.

# find all files that have the word "reservation"
$ ag -g reservation
app/models/reservation.rb
spec/models/reservation_spec.rb

Match based on filename

If you wanted to find something in only certain types of files, you can use -G. It’s similar to the lowercase -g, except it match inside the file and match the file name.

# find instances of "city" where the filename contains the word "model"
$ ag city -G model
app/models/hotel.rb
22: city: "New York"
35: destination.city != source.city
test/models/reservation.rb
13: city = "Montreal"