_pm_irbrc.rb

# pm - Print methods of objects in irb/console sessions.
# Goes in ~./irbrc 
#
  begin # Utility methods
    def pm(obj, *options) # Print methods
      methods = obj.methods
      methods -= Object.methods unless options.include? :more
      filter = options.select {|opt| opt.kind_of? Regexp}.first
      methods = methods.select {|name| name =~ filter} if filter

      data = methods.sort.collect do |name|
        method = obj.method(name)
        if method.arity == 0
          args = "()"
        elsif method.arity > 0
          n = method.arity
          args = "(#{(1..n).collect {|i| "arg#{i}"}.join(", ")})"
        elsif method.arity < 0
          n = -method.arity
          args = "(#{(1..n).collect {|i| "arg#{i}"}.join(", ")}, ...)"
        end
        klass = $1 if method.inspect =~ /Method: (.*?)#/
        [name, args, klass]
      end
      max_name = data.collect {|item| item[0].size}.max
      max_args = data.collect {|item| item[1].size}.max
      data.each do |item| 
        print "#{ANSI_LGRAY}#{item[0].rjust(max_name)}#{ANSI_RESET}"
        print "#{ANSI_BLUE}#{item[1].ljust(max_args)}#{ANSI_RESET}"
        print "#{ANSI_RED}#{item[2]}#{ANSI_RESET}\n"
      end
      data.size
    end
  end

output

>> pm Time
                      _load(arg1)                 
             _original_load(arg1)                 
                         at(arg1, ...)            
                    current()                     Class(ActiveSupport::CoreExtensions::Time::Zones::ClassMethods)
              days_in_month(arg1, arg2, ...)      Class(ActiveSupport::CoreExtensions::Time::Calculations::ClassMethods)
                         gm(arg1, ...)            
                   httpdate(arg1)                 
                    iso8601(arg1)                 
                      local(arg1, ...)            
                 local_time(arg1, ...)            Class(ActiveSupport::CoreExtensions::Time::Calculations::ClassMethods)
                     mktime(arg1, ...)            
                        now(arg1, ...)            
                      parse(arg1, arg2, ...)      
                    rfc2822(arg1)                 
                     rfc822(arg1)                 
time_with_datetime_fallback(arg1, arg2, arg3, ...)Class(ActiveSupport::CoreExtensions::Time::Calculations::ClassMethods)
                      times()                     
                   use_zone(arg1)                 Class(ActiveSupport::CoreExtensions::Time::Zones::ClassMethods)
                        utc(arg1, ...)            
                   utc_time(arg1, ...)            Class(ActiveSupport::CoreExtensions::Time::Calculations::ClassMethods)
                  xmlschema(arg1)                 
                   yaml_new(arg1, arg2, arg3)     
                       zone()                     Class(ActiveSupport::CoreExtensions::Time::Zones::ClassMethods)
                      zone=(arg1)                 Class(ActiveSupport::CoreExtensions::Time::Zones::ClassMethods)
               zone_default()                     Class(ActiveSupport::CoreExtensions::Time::Zones::ClassMethods)
              zone_default=(arg1)                 Class(ActiveSupport::CoreExtensions::Time::Zones::ClassMethods)
                zone_offset(arg1, arg2, ...)      
=> 27
>> time = Time.new
=> Sat Aug 14 14:58:29 -0500 2010
>> pm time
                       +(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
                       -(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
                   _dump(arg1, ...) Time
          _original_dump(arg1, ...) Time
         acts_like_time?()          Time(ActiveSupport::CoreExtensions::Time::Behavior)
                 advance(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
                  after?(arg1)      Time(BeforeAndAfter)
                     ago(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
                 asctime()          Time
     at_beginning_of_day()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
   at_beginning_of_month()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
 at_beginning_of_quarter()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
    at_beginning_of_week()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
    at_beginning_of_year()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
         at_end_of_month()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
       at_end_of_quarter()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
          at_end_of_week()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
          at_end_of_year()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
             at_midnight()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                 before?(arg1)      Time(BeforeAndAfter)
        beginning_of_day()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
      beginning_of_month()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
    beginning_of_quarter()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
       beginning_of_week()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
       beginning_of_year()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                between?(arg1, arg2)Time(Comparable)
                  change(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
   compare_with_coercion(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
compare_without_coercion(arg1)      Time
                   ctime()          Time
                     day()          Time
                    dst?()          Time
              end_of_day()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
            end_of_month()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
          end_of_quarter()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
             end_of_week()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
             end_of_year()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
        formatted_offset(arg1, ...) Time(ActiveSupport::CoreExtensions::Time::Conversions)
                 future?()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                   getgm()          Time
                getlocal()          Time
                  getutc()          Time
                    gmt?()          Time
              gmt_offset()          Time
                  gmtime()          Time
                  gmtoff()          Time
                    hour()          Time
                httpdate()          Time
                      in(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
            in_time_zone(arg1, ...) Time(ActiveSupport::CoreExtensions::Time::Zones)
                   isdst()          Time
                 iso8601(arg1, ...) Time
              last_month()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
               last_year()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
               localtime()          Time
                    mday()          Time
                midnight()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                     min()          Time
     minus_with_coercion(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
     minus_with_duration(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
  minus_without_coercion(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
  minus_without_duration(arg1)      Time
                     mon()          Time
                  monday()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                   month()          Time
              months_ago(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
            months_since(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
              next_month()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
               next_week(arg1, ...) Time(ActiveSupport::CoreExtensions::Time::Calculations)
               next_year()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                   past?()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
      plus_with_duration(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
   plus_without_duration(arg1)      Time
              prev_month()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
               prev_year()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                 rfc2822()          Time
                  rfc822()          Time
                     sec()          Time
  seconds_since_midnight()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                   since(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
                strftime(arg1)      Time
                    succ()          Time
                 to_date()          Time
             to_datetime()          Time
            to_default_s()          Time
                    to_f()          Time
          to_formatted_s(arg1, ...) Time(ActiveSupport::CoreExtensions::Time::Conversions)
                    to_i()          Time
                 to_time()          Time(ActiveSupport::CoreExtensions::Time::Conversions)
                  today?()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                tomorrow()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                  tv_sec()          Time
                 tv_usec()          Time
                    usec()          Time
                     utc()          Time
                    utc?()          Time
              utc_offset()          Time
                    wday()          Time
               xmlschema(arg1, ...) Time
                    yday()          Time
                    year()          Time
               years_ago(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
             years_since(arg1)      Time(ActiveSupport::CoreExtensions::Time::Calculations)
               yesterday()          Time(ActiveSupport::CoreExtensions::Time::Calculations)
                    zone()          Time
=> 105