brew commands

Shows a list of built-in commands (but not shortcuts) and searches
for any external commands on the path.

Closes Homebrew/homebrew#22509.

4 files changed, 38 insertions, 0 deletions

diff --git a/Library/Contributions/brew_bash_completion.sh b/Library/Contributions/brew_bash_completion.sh
index 28a57c6c5..c55b78925 100644
--- a/Library/Contributions/brew_bash_completion.sh
+++ b/Library/Contributions/brew_bash_completion.sh
@@ -403,6 +403,7 @@ _brew ()
             audit
             cat
             cleanup
+            commands
             create
             deps
             diy configure
diff --git a/Library/Contributions/brew_zsh_completion.zsh b/Library/Contributions/brew_zsh_completion.zsh
index e497cd11e..878a3f9d3 100644
--- a/Library/Contributions/brew_zsh_completion.zsh
+++ b/Library/Contributions/brew_zsh_completion.zsh
@@ -27,6 +27,7 @@ _1st_arguments=(
   'audit:check formulae for Homebrew coding style'
   'cat:display formula file for a formula'
   'cleanup:uninstall unused and old versions of packages'
+  'commands:show a list of commands'
   'create:create a new formula'
   'deps:list dependencies and dependants of a formula'
   'doctor:audits your installation for common issues'
diff --git a/Library/Contributions/manpages/brew.1.md b/Library/Contributions/manpages/brew.1.md
index 0e3c11584..e2b94821e 100644
--- a/Library/Contributions/manpages/brew.1.md
+++ b/Library/Contributions/manpages/brew.1.md
@@ -64,6 +64,9 @@ Note that these flags should only appear after a command.
     versions of formula. Note downloads for any installed formula will still not be
     deleted. If you want to delete those too: `rm -rf $(brew --cache)`
 
+  * `commands`:
+    Show a list of built-in and external commands.
+
   * `create <URL> [--autotools|--cmake] [--no-fetch] [--set-name <name>] [--set-version <version>]`:
     Generate a formula for the downloadable file at <URL> and open it in the editor.
     Homebrew will attempt to automatically derive the formula name
diff --git a/Library/Homebrew/cmd/commands.rb b/Library/Homebrew/cmd/commands.rb
new file mode 100644
index 000000000..b9bbb12ec
--- /dev/null
+++ b/Library/Homebrew/cmd/commands.rb
@@ -0,0 +1,33 @@
+module Homebrew extend self
+  def paths
+    @paths ||= ENV['PATH'].split(File::PATH_SEPARATOR).collect do |p|
+      begin
+        File.expand_path(p).chomp('/')
+      rescue ArgumentError
+        onoe "The following PATH component is invalid: #{p}"
+      end
+    end.uniq.compact
+  end
+
+  def commands
+    # Find commands in Homebrew/cmd
+    cmds = (HOMEBREW_REPOSITORY/"Library/Homebrew/cmd").
+           children(with_directory=false).
+           map {|f| File.basename(f, '.rb')}
+    puts "Built-in commands"
+    puts_columns cmds
+
+    # Find commands in the path
+    exts =  paths.map{ |p| Dir["#{p}/*"] }.flatten.
+            map{    |f| File.basename f }.
+            select{ |f| f =~ /^brew-(.+)/ }.
+            map{    |f| File.basename(f, '.rb')[5..-1] }.
+            reject{ |f| f =~ /\./ }
+
+    unless exts.empty?
+      puts
+      puts "External commands"
+      puts_columns exts
+    end
+  end
+end