Class: File

Inherits:
Object
  • Object
show all
Defined in:
lib/fedux_org_stdlib/core_ext/file/which.rb

Overview

File class

Constant Summary collapse

MSWINDOWS = 
false
WIN32EXTS = 
'.{exe,com,bat}'

Class Method Summary collapse

Class Method Details

.which(program, path = ENV['PATH']) ⇒ String, NilClass

Search program in search path

Parameters:

  • program (String) —

    The program to look for

  • path (String) (defaults to: ENV['PATH']) —

    The search path

Returns:

  • (String, NilClass) —

    If the program could be found in search path, the full path will be returned otherwise ‘#which` returns nil.



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# File 'lib/fedux_org_stdlib/core_ext/file/which.rb', line 33

def which(program, path = ENV['PATH'])
  fail ArgumentError, path if path.blank?

  return nil if program.blank?

  # Bail out early if an absolute path is provided.
  if program =~ %r{^/|^[a-z]:[/]}i
    program += WIN32EXTS if MSWINDOWS && File.extname(program).blank?
    found = Dir[program].first
    if found && File.executable?(found) && !File.directory?(found)
      return found
    else
      return nil
    end
  end

  # Iterate over each path glob the dir + program.
  path.split(File::PATH_SEPARATOR).each do |dir|
    dir = File.expand_path(dir)

    next unless File.exist?(dir) # In case of bogus second argument
    file = File.join(dir, program)

    # Dir[] doesn't handle backslashes properly, so convert them. Also, if
    # the program name doesn't have an extension, try them all.
    if MSWINDOWS
      file = file.tr('\\', '/')
      file += WIN32EXTS if File.extname(program).blank?
    end

    found = Dir[file].first

    next if !found || !File.executable?(found) || File.directory?(found)

    # Convert all forward slashes to backslashes if supported
    found.tr!(File::SEPARATOR, File::ALT_SEPARATOR) if File::ALT_SEPARATOR

    return found
  end

  nil
end