[ruby/irb] Document a full list of commands

(https://github.com/ruby/irb/pull/451)

* Document a full list of commands

* Document debug as well

* Make it less duplicated

1 files changed, 44 insertions, 0 deletions

diff --git a/README.md b/README.md
index 35ef2d9e89..5b1f21abc9 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,50 @@ see [Building Ruby](doc/contributing/building_ruby.md)
 
 https://www.ruby-lang.org/
 
+## Commands
+
+The following commands are available on IRB.
+
+* `cwws`
+  * Show the current workspace.
+* `cb`, `cws`, `chws`
+  * Change the current workspace to an object.
+* `bindings`, `workspaces`
+  * Show workspaces.
+* `pushb`, `pushws`
+  * Push an object to the workspace stack.
+* `popb`, `popws`
+  * Pop a workspace from the workspace stack.
+* `load`
+  * Load a Ruby file.
+* `require`
+  * Require a Ruby file.
+* `source`
+  * Loads a given file in the current session.
+* `irb`
+  * Start a child IRB.
+* `jobs`
+  * List of current sessions.
+* `fg`
+  * Switches to the session of the given number.
+* `kill`
+  * Kills the session with the given number.
+* `help`
+  * Enter the mode to look up RI documents.
+* `irb_info`
+  * Show information about IRB.
+* `ls`
+  * Show methods, constants, and variables.
+    `-g [query]` or `-G [query]` allows you to filter out the output.
+* `measure`
+  * `measure` enables the mode to measure processing time. `measure :off` disables it.
+* `$`, `show_source`
+  * Show the source code of a given method or constant.
+* `@`, `whereami`
+  * Show the source code around binding.irb again.
+* `debug`
+  * Start the debugger of debug.gem.
+
 ## Documentation
 
 - [English](https://docs.ruby-lang.org/en/master/index.html)