Add Select A Specific Rails Version To Install as a Rails 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).
 
-_1366 TILs and counting..._
+_1367 TILs and counting..._
 
 ---
 
@@ -903,6 +903,7 @@ _1366 TILs and counting..._
 - [Schedule Sidekiq Jobs Out Into The Future](rails/schedule-sidekiq-jobs-out-into-the-future.md)
 - [Secure Passwords With Rails And Bcrypt](rails/secure-passwords-with-rails-and-bcrypt.md)
 - [Select A Select By Selector](rails/select-a-select-by-selector.md)
+- [Select A Specific Rails Version To Install](rails/select-a-specific-rails-version-to-install.md)
 - [Select Value For SQL Counts](rails/select-value-for-sql-counts.md)
 - [Serialize With fast_jsonapi In A Rails App](rails/serialize-with-fast-jsonapi-in-a-rails-app.md)
 - [Set A Timestamp Field To The Current Time](rails/set-a-timestamp-field-to-the-current-time.md)

rails/select-a-specific-rails-version-to-install.md

@@ -0,0 +1,28 @@
+# Select A Specific Rails Version To Install
+
+We can install a specific Rails version with `gem` using the version flag.
+
+```bash
+$ gem install rails --version 7.1.3
+```
+
+That's only if we already know which specific version we are intending to
+install.
+
+A better version of this would show us a list of available version and let us
+select the one we want.
+
+We can do this by fetching all remote Rails versions with `gem`, splitting that
+output up into a single version per line, and then piping that to an `fzf`
+prompt. The version we navigate to and select will be fed into the `gem
+install` command.
+
+```bash
+gem install rails --version $(
+  gem list rails --exact --remote --all \
+  | sed -n 's/.*(\([^)]*\)).*/\1/p' \
+  | tr ',' '\n' \
+  | sed 's/^ //' \
+  | fzf
+)
+```