use include/exclude lists for detection

README.md

@@ -12,6 +12,18 @@ Then, in your .profile (or somewhere you can set env variables)
 
 And you're done!
 
+## Configuration
+
+Though you can let noexec do it's own thing and rely on looking up your binary via your Gemfile, you can also specify which binaries you want included or excluded. Create a .noexec.yaml file along side any Gemfiles you want to use. Then, to enable (or disable) the usage of your particular binary into your bundle, add an include or exclude section. For example:
+
+### .noexec.yaml
+
+    exclude: [rake]
+
+Or, 
+
+    include: [irb, ruby]
+
 ## How does this work?
 
 It adds a script to every execution of ruby via the RUBYOPT environment variable. Then, when you run ruby, it takes a look at your working directory, and every directory above it until it can find a `Gemfile`. If the executable you're running is present in your Gemfile, it switches to using that `Gemfile` instead (via `Bundle.setup`).

lib/noexec/auto.rb

@@ -17,27 +17,46 @@ module Noexec
 
     extend self
 
+    def log(msg)
+      puts msg if DEBUG
+    end
+
     def candidate?(gemfile, bin)
+      config_file = File.expand_path('../.noexec.yaml', gemfile)
+      log "Considering #{config_file.inspect}"
+      if File.exist?(config_file)
+        log "Using config file at #{config_file}"
+        config = YAML::load_file(config_file)
+        raise "You cannot have both an include and exclude section in your #{config_file.inspect}" unless config['include'].nil? ^ config['exclude'].nil?
+        if config['include'] && config['include'].include?(bin)
+          log "Binary included by config"
+          return true
+        elsif config['exclude'] && config['exclude'].include?(bin)
+          log "Binary excluded by config"
+          return false
+        end
+        log "Config based matching didn't find it, resorting to Gemfile lookup"
+      end
       ENV['BUNDLE_GEMFILE'] = gemfile
       Bundler.load.specs.each do |spec|
         next if spec.name == 'bundler'
-        return spec if %w(ruby irb).include?(bin) || spec.executables.include?(bin)
+        return true if %w(ruby irb).include?(bin) || spec.executables.include?(bin)
       end
-      nil
+      false
     ensure
       Bundler.reset!
     end
 
     def setup
-      puts "Noexec" if DEBUG
+      log "Noexec"
       return if File.basename($0) == 'bundle'
       return if ENV['BUNDLE_GEMFILE']
       gemfile = File.join(CURRENT, "Gemfile")
       while true
         if File.exist?(gemfile)
-          puts "Examining #{gemfile}" if DEBUG
+          log "Examining #{gemfile}"
           if Noexec.candidate?(gemfile, File.basename($0))
-            puts "Using #{gemfile}" if DEBUG
+            log "Using #{gemfile}"
             ENV['BUNDLE_GEMFILE'] = gemfile
             Bundler.setup
             return
@@ -47,7 +66,7 @@ def setup
         break if new_gemfile == gemfile
         gemfile = new_gemfile
       end
-      puts "No valid Gemfile found, moving on" if DEBUG
+      log "No valid Gemfile found, moving on"
     end
   end
 

lib/noexec/version.rb

@@ -1,3 +1,3 @@
 module Noexec
-  VERSION = "0.0.4"
+  VERSION = "0.1.0"
 end