Console plotting in erlang script (escript)

tgraph.erl

#!/usr/bin/env escript
%% -*- erlang -*-
%%! -smp disable
%% Author: Drew Gulino
-module(tgraph).
 
-export([main/1]).
 
main(CmdLine) ->
 OptSpecList = option_spec_list(),
 case getopt:parse(OptSpecList, CmdLine) of
  {ok, {Options, NonOptArgs}} ->
   true;
  {error, {Reason, Data}} ->
   Options = [],
   NonOptArgs = [],
   io:format("Error: ~s ~p~n~n", [Reason, Data]),
   version(),
   getopt:usage(OptSpecList, "tgraph")
 end,
 Symbol = get_opt_value(symbol,Options),
 Columns = get_opt_value(columns,Options),
 Display_number = get_opt_value(display_number,Options),
 Threshold = get_opt_value(threshold,Options),
 Maximum = get_opt_value(maximum,Options),
 
 Bold = strip_newlines(os:cmd("tput bold")),
 Init = strip_newlines(os:cmd("tput init")),
 Dim = strip_newlines(os:cmd("tput sgr0")),
 Red = strip_newlines(os:cmd("tput setaf 1")),
 %Green = strip_newlines(os:cmd("tput setaf 2")),
 %Yellow = strip_newlines(os:cmd("tput setaf 3")),
 %Blue = strip_newlines(os:cmd("tput setaf 4")),
 %Magenta = strip_newlines(os:cmd("tput setaf 5")),
 
 case NonOptArgs of
  [] ->
  F = standard_io;
  _ ->
  {ok, F} = file:open(NonOptArgs, read)
 end,
  proc_file(F, {Symbol, Columns, Display_number, Threshold, Maximum} , {Bold, Init, Dim, Red}).
 
version() ->
 io:format("Version: 1.1\n").
 
get_opt_value(Key, Options) ->
 case lists:keyfind(Key,1,Options) of
  {Key, Value} ->
  Value
 end,
 Value.
 
option_spec_list() ->
 %CurrentUser = os:getenv("USER"),
 [
 %% {Name, ShortOpt, LongOpt, ArgSpec, HelpMsg}
 {help, $h, "help", undefined, "Show the program options"},
 {version, $v, "version", undefined, "Version"},
 {display_number, $n, "display_number", {boolean, true}, "Display number w/graph"},
 {columns, $c, "columns", {integer, 72}, "Display columns (default = 72)"},
 {symbol, $s, "symbol", {string, "*"}, "Symbol to display (default = '*')"},
 {threshold, $t, "threshold", {integer, 0}, "Will color lines over this value"},
 {maximum, $m, "maximum", {integer, 0}, "Presets the scale for this maximum value (default = 0)"}
 ].
 
proc_file(F, Options, Tput) ->
{Symbol, Columns, Display_number, Threshold, Maximum} = Options,
{Bold, Init, Dim, Red} = Tput,
%Columns = erlang:list_to_integer(os:cmd("tput cols")) - 8},
L = io:get_line(F, ''),
 case L of
  eof ->
   ok;
  "\n" ->
   false;
  Line ->
   Stripped = strip_newlines(Line),
   Num = cast_to_integer(Stripped),
   io:put_chars(Init),
   case Num > 0 of
    true ->
     case Num >= Maximum of
      true ->
       NewMax = Num,
       io:put_chars(Bold);
      false ->
       NewMax = Maximum,   
       io:put_chars(Dim)
     end,
     Scale = Columns / NewMax,
     Graph = lists:map(fun(_) -> io_lib:format(Symbol,[]) end , lists:seq(1,erlang:round(Num * Scale))),
     case Threshold of
      0 ->
       false;
      _ ->
       case Num >= Threshold of
        true ->
         io:put_chars(Red);
        false ->
         %io:put_chars(Init)
         false
       end
     end,
     case Display_number of
      true ->
       io:format("~s~p~n",[Graph,Num]);
      false ->
       io:format("~p~n",[Graph])
     end,                               
     NewOptions = {Symbol, Columns, Display_number, Threshold, NewMax},
     proc_file(F,NewOptions, Tput);
    false ->
     io:put_chars(Dim),
     io:put_chars(Init),
     io:format("~p~n",[Num]),
     proc_file(F,Options, Tput)
   end
 end.
 
strip_newlines(String) ->
 string:strip(re:replace(String,"(.*)[\n\r]","\\1", [global,{return,list}])).
 
cast_to_integer([]) ->
 [];
cast_to_integer(Input) when is_integer(Input) ->
 Input;
cast_to_integer(Input) when is_float(Input) ->
 erlang:round(Input);
cast_to_integer(Input) when is_list(Input)->
 case lists:member($., Input) of
  true ->
   erlang:round(erlang:list_to_float(Input));
  false ->     
   erlang:list_to_integer(Input)
end.