Module: TrickBag::Filesystem

Defined in:
lib/trick_bag/filesystem/filesystem.rb

Class Method Summary collapse

Class Method Details

.running_as_script?(__file__) ⇒ Boolean

When the file’s behavior needs to differ when running as a script and not running as a script, this method can be called to report which of the two states it is.

Sometimes we want to see if a given file is being run as a script, as opposed to loaded by other Ruby code. For example, the script at github.com/keithrbennett/macwifi/blob/master/bin/mac-wifi is normally run as a script (either by running the file directly, or by running the executable’s binstub installed by the gem), but it can also be loaded so that the model can be used by custom code. When run as a script, it parses the command line and executes a task, sending text to stdout.

Parameters:

  • __file__ —

    • !!! __FILE__ must be passed as the __file__ argument for this to work correctly !!!

Returns:

  • (Boolean) —

    true if the passed file is being run as a script, else false



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# File 'lib/trick_bag/filesystem/filesystem.rb', line 17

def running_as_script?(__file__)

  # Here is some sample state, when running a file as a gem executable:
  # __FILE__ = /Users/kbennett/.rvm/gems/ruby-2.4.0/gems/mac-wifi-1.0.0/bin/mac-wifi
  # $0 =       /Users/kbennett/.rvm/gems/ruby-2.4.0/bin/mac-wifi
  # GEM_PATH = /Users/kbennett/.rvm/gems/ruby-2.4.0:/Users/kbennett/.rvm/gems/ruby-2.4.0@global

  # Please enable this code and report its output if you report any issues with this method:
  # puts "__file__ = #{__file__}"
  # puts "$0 =       #{$0}"
  # puts "GEM_PATH = #{ENV['GEM_PATH']}"

  return true if __file__ == $0
  return false if File.basename(__file__) != File.basename($0)

  # If here, then filespecs are different but have the same basename.
  gem_paths = ENV['GEM_PATH'].split(File::PATH_SEPARATOR)
  basename = File.basename($0)
  gem_paths.any? do |path|
    ($0 == File.join(path, 'bin', basename)) \
        && \
        (path == File.expand_path(File.join(__file__, '..', '..', '..', '..')))
  end
end