How do you tell a Ruby program to wait an arbitrary amount of time before moving on to the next line of code?
7 Answers
Like this:
sleep(num_secs) The num_secs value can be an integer or float.
Also, if you're writing this within a Rails app, or have included the ActiveSupport library in your project, you can construct longer intervals using the following convenience syntax:
sleep(4.minutes) # or, even longer... sleep(2.hours); sleep(3.days) # etc., etc. # or shorter sleep(0.5) # half a second Use sleep like so:
sleep 2 That'll sleep for 2 seconds.
Be careful to give an argument. If you just run sleep, the process will sleep forever. (This is useful when you want a thread to sleep until it's woken.)
I find until very useful with sleep. example:
> time = Time.now > sleep 2.seconds until Time.now > time + 10.seconds # breaks when true > # or > sleep 2 and puts 'still sleeping' until Time.now > time + 10 > # or > sleep 1.seconds until !req.loading # suggested by ohsully Like this
sleep(no_of_seconds)
Or you may pass other possible arguments like:
sleep(5.seconds)
sleep(5.minutes)
sleep(5.hours)
sleep(5.days)
Implementation of seconds/minutes/hours, which are rails methods. Note that implicit returns aren't needed, but they look cleaner, so I prefer them. I'm not sure Rails even has .days or if it goes further, but these are the ones I need.
class Integer def seconds return self end def minutes return self * 60 end def hours return self * 3600 end def days return self * 86400 end end After this, you can do: sleep 5.seconds to sleep for 5 seconds. You can do sleep 5.minutes to sleep for 5 min. You can do sleep 5.hours to sleep for 5 hours. And finally, you can do sleep 5.days to sleep for 5 days... You can add any method that return the value of self * (amount of seconds in that timeframe). As an exercise, try implementing it for months!
sleep 6 will sleep for 6 seconds. For a longer duration, you can also use sleep(6.minutes) or sleep(6.hours).
This is an example of using sleep with sidekiq
require 'sidekiq' class PlainOldRuby include Sidekiq::Worker def perform(how_hard="super hard", how_long=10) sleep how_long puts "Workin' #{how_hard}" end end sleep for 10 seconds and print out "Working super hard" .
