Class: Vagrant::Util::Which

Inherits:
Object
  • Object
show all
Defined in:
lib/vagrant/util/which.rb

Class Method Summary collapse

Class Method Details

.which(cmd, **opts) ⇒ String

Cross-platform way of finding an executable in the PATH.

which('ruby') #=> /usr/bin/ruby

This code is adapted from the following post by mislav: http://stackoverflow.com/questions/2108727/which-in-ruby-checking-if-program-exists-in-path-from-ruby

Parameters:

  • cmd (String) —

    The command to search for in the PATH.

  • opts (Hash) —

    Optional flags @option [Boolean] :original_path Search within original path if available

Returns:

  • (String) —

    The full path to the executable or nil if not found.



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# File 'lib/vagrant/util/which.rb', line 20

def self.which(cmd, **opts)
  exts = nil

  if !Platform.windows? || ENV['PATHEXT'].nil?
    # If the PATHEXT variable is empty, we're on *nix and need to find
    # the exact filename
    exts = ['']
  elsif File.extname(cmd).length != 0
    # On Windows: if filename contains an extension, we must match that
    # exact filename
    exts = ['']
  else
    # On Windows: otherwise try to match all possible executable file
    # extensions (.EXE .COM .BAT etc.)
    exts = ENV['PATHEXT'].split(';')
  end

  if opts[:original_path]
    search_path = ENV.fetch('VAGRANT_OLD_ENV_PATH', ENV['PATH'])
  else
    search_path = ENV['PATH']
  end

  SilenceWarnings.silence! do
    search_path.encode('UTF-8', 'binary', invalid: :replace, undef: :replace, replace: '').split(File::PATH_SEPARATOR).each do |path|
      exts.each do |ext|
        exe = "#{path}#{File::SEPARATOR}#{cmd}#{ext}"
        return exe if File.executable? exe
      end
    end
  end

  return nil
end