tgraph.ex

require Logger

defmodule Tgraph do

  def main(args) do
    Logger.info inspect args
    options = parse_args(args)
    f = Dict.get(options,:file,:stdio)
    case is_atom(f) do
      true -> f
      false -> {:ok, f} = File.open f
    end
    {cols, _} = System.cmd("tput",["cols"],[])
    {cols, _} = Integer.parse(String.strip(cols))
    cols = cols - 8
    options = Dict.put(options, :columns, cols)
    maximum = Dict.get(options,:maximum,1)
    symbol = Dict.get(options,:symbol,"*")
    columns = Dict.get(options,:columns)
    display_number = Dict.get(options,:display_number,false)
    threshold = Dict.get(options,:threshold,0)
    proc_file(f, maximum, symbol, columns, display_number, threshold )
  end

  def parse_args(args) do
    {options , _, _} = OptionParser.parse(args,
      switches: [
        help:             :boolean,
        maximum:          :integer,
        symbol:           :string,
        columns:          :integer,
        display_number:   :boolean,
        threshold:        :integer,
        file:             :string
      ],
      aliases: [
        h: :help,
        m: :maximum,
        s: :symbol,
        c: :columns,
        d: :display_number,
        t: :threshold,
        f: :file
      ]
    )
    options
  end

  def version do
    IO.puts "version: 0.1"
  end

  def proc_file(f, maximum, symbol, columns, display_number, threshold ) do
    l = IO.gets(f, '')
    case l do
      {:error, reason} ->
        Logger.info inspect {:error, reason}
      :eof ->
        :ok
      "\n" ->
        false
      line ->
        stripped = String.strip(line,?\n)
        {num, _} = Integer.parse(stripped)
        IO.write IO.ANSI.reset()
        case num > 0 do
          true ->
            case num >= maximum do
              true ->
                newmax = num
                IO.write IO.ANSI.yellow()
              false ->
                newmax = maximum
                IO.write IO.ANSI.normal()
            end
            scale = columns / newmax
            num_chars = round(num * scale) + 1
            graph = List.to_string(Enum.map(1..num_chars, fn n -> symbol end))
            case threshold do
              0 ->
                false
              _ ->
                case num >= threshold do
                  true ->
                    IO.write IO.ANSI.red()
                  false ->
                    IO.write IO.ANSI.reset()
                    false
                end
            end
            case display_number do
              true ->
                IO.puts "#{graph}#{num}"
              false ->
                IO.puts "#{graph}"
            end
            proc_file(f, newmax, symbol, columns, display_number, threshold)
          false ->
            IO.write IO.ANSI.normal()
            IO.write IO.ANSI.reset()
            IO.puts "#{num}"
            proc_file(f, maximum, symbol, columns, display_number, threshold)
        end
    end
  end
end

mix new tgraph
copy gist to tgraph/lib/tgraph.ex
cd tgraph
edit mix.exs:

  def project do
    [app: :tgraph,
     version: "0.0.1",
     elixir: "~> 1.0.0",
     escript: [main_module: Tgraph],
     deps: deps]
  end

mix escript.build

while true; do echo $RANDOM  ;done | ./tgraph -t 10000 -d

************4142
************************************************************************************30380
*************************************************17829
***************************************************************************************31698
****************************************************************************27497
************************************************************************************30575
*******************************************15394
****************5380
*****************************************************************************27879
**********************************************************20853
************************8430
****************************9812

(values over 10K are colored red (color not supported in github markdown))