CODEWITHSUNDEEP
ruby
Sato
Sato

Reputation: 8622

Dynamically reload somefile.rb in runtime?

I have two Ruby files: exec.rb and lib.rb. lib.rb is required by exec.rb. Every time I modify lib.rb, I need to restart exec.rb.

Is it possible to have exec.rb reload lib.rb while running?

Upvotes: 1

Views: 1101

Answers (2)

the Tin Man
the Tin Man

Reputation: 160631

It's possible to do this using File.mtime and comparing the last-modified timestamp for lib.rb.

In your code, get the mtime when you first load the file:

last_mtime = File.mtime('lib.rb')
load 'lib.rb'

Later, in a loop as you process, check again to see if the modification time changed, and reload if necessary:

current_mtime = File.mtime('lib.rb')
if (current_mtime != last_mtime)
  last_mtime = current_mtime
  load 'lib.rb'
end

I've used a similar technique in the past, and it worked well. I set mine up so it only checked every five minutes, but your needs might be different.

Upvotes: 1

Sergio Tulentsev
Sergio Tulentsev

Reputation: 230561

You can subscribe to file change notifications. Here's a lib for osx: rb-fsevent.

When you get notification that the file changed, you can reload it.

filename = './lib.rb' # get file name from event
load filename

You should use load instead of require, because require loads file only once and then does not load it again.

Upvotes: 1

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