Add Progress Reporting To Long Running Script as a Ruby TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1355 TILs and counting..._
+_1356 TILs and counting..._
 
 ---
 
@@ -1045,6 +1045,7 @@ _1355 TILs and counting..._
 - [A Shorthand For Rerunning Failed Tests With RSpec](ruby/a-shorthand-for-rerunning-failed-tests-with-rspec.md)
 - [Add Comments To Regex With Free-Spacing](ruby/add-comments-to-regex-with-free-spacing.md)
 - [Add Linux As A Bundler Platform](ruby/add-linux-as-a-bundler-platform.md)
+- [Add Progress Reporting To Long-Running Script](ruby/add-progress-reporting-to-long-running-script.md)
 - [Are They All True?](ruby/are-they-all-true.md)
 - [Assert About An Object's Attributes With RSpec](ruby/assert-about-an-objects-attributes-with-rspec.md)
 - [Assoc For Hashes](ruby/assoc-for-hashes.md)

ruby/add-progress-reporting-to-long-running-script.md

@@ -0,0 +1,46 @@
+# Add Progress Reporting To Long-Running Script
+
+A script that is going to iterate over and process a ton of data can take a
+long time to run. It can be hard to predict how long it will take to run. So,
+it is nice to have some indication of it's progress as it goes.
+
+Here is a small snippet that I add to the main loop so that I have some
+feedback while the script runs:
+
+```ruby
+running_count = 0
+
+tons_of_data.each do |item|
+  running_count += 1
+  if running_count % 1000 == 0
+    print '@'
+  elsif running_count % 100 == 0
+    print '*'
+  else
+    print '.'
+  end
+
+  # process this `item` ...
+end
+```
+
+Then I get some output that looks like this over time as the script runs.
+
+```
+...............................................................................
+....................*..........................................................
+.........................................*.....................................
+..............................................................*................
+...............................................................................
+....*..........................................................................
+.........................*.....................................................
+..............................................*................................
+...................................................................*...........
+...............................................................................
+.........*.....................................................................
+..............................*................................................
+...................................................@..................
+```
+
+I can get a sense of how quickly it is processing each record and roughly count
+how far along it is.