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) ⇒ 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.

Returns:

  • (String) —

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



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# File 'lib/vagrant/util/which.rb', line 15

def self.which(cmd)
  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

  ENV['PATH'].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

  return nil
end