def group_exists?(name)
      groups = Set.new
      Etc.group { |g| groups << g.name }
      groups.include?(name)
    end
def group_exists?(name)
      groups = Set.new
      Etc.group { |g| groups << g.name }
      groups.include?(name)
    end
Check if group with specified name exists in the system.

 === Parameters
 name(String):: group's name

 === Block
 If a block is given, it will be yielded to with various status messages
 suitable for display to the user.

 === Return
 exist_status(Boolean):: true if exists; otherwise false