Allows you to specify the output file

lib/uplot/command.rb

@@ -25,6 +25,7 @@ module Uplot
       delimiter = parser.delimiter
       transpose = parser.transpose
       headers   = parser.headers
+      pass      = parser.pass
       output    = parser.output
       count     = parser.count
       fmt       = parser.fmt
@@ -41,28 +42,42 @@ module Uplot
         @raw_inputs << input
         @data = Preprocessing.input(input, delimiter, headers, transpose)
         pp @data if @debug
-        case command
-        when :bar, :barplot
-          Plot.barplot(data, params, @count)
-        when :count, :c
-          Plot.barplot(data, params, count = true)
-        when :hist, :histogram
-          Plot.histogram(data, params)
-        when :line, :lineplot
-          Plot.line(data, params)
-        when :lines, :lineplots
-          Plot.lines(data, params, fmt)
-        when :scatter, :s
-          Plot.scatter(data, params, fmt)
-        when :density, :d
-          Plot.density(data, params, fmt)
-        when :box, :boxplot
-          Plot.boxplot(data, params)
-        else
-          raise "unrecognized plot_type: #{command}"
-        end.render($stderr)
+        plot = case command
+               when :bar, :barplot
+                 Plot.barplot(data, params, @count)
+               when :count, :c
+                 Plot.barplot(data, params, count = true)
+               when :hist, :histogram
+                 Plot.histogram(data, params)
+               when :line, :lineplot
+                 Plot.line(data, params)
+               when :lines, :lineplots
+                 Plot.lines(data, params, fmt)
+               when :scatter, :s
+                 Plot.scatter(data, params, fmt)
+               when :density, :d
+                 Plot.density(data, params, fmt)
+               when :box, :boxplot
+                 Plot.boxplot(data, params)
+               else
+                 raise "unrecognized plot_type: #{command}"
+               end
 
-        print input if output
+        if output.is_a?(IO)
+          plot.render(output)
+        else
+          File.open(output, 'w') do |f|
+            plot.render(f)
+          end
+        end
+
+        if pass.is_a?(IO)
+          print input
+        elsif pass
+          File.open(pass, 'w') do |f|
+            f.print(input)
+          end
+        end
       end
     end
   end

lib/uplot/command/parser.rb

@@ -7,7 +7,7 @@ module Uplot
   class Command
     class Parser
       attr_reader :command, :params,
-                  :delimiter, :transpose, :headers, :output, :count, :fmt, :debug
+                  :delimiter, :transpose, :headers, :pass, :output, :count, :fmt, :debug
 
       def initialize
         @command = nil
@@ -16,7 +16,8 @@ module Uplot
         @delimiter  = "\t"
         @transpose  = false
         @headers    = nil
-        @output     = false
+        @pass       = false
+        @output     = $stderr
         @count      = false
         @fmt        = 'xyy'
         @debug      = false
@@ -26,7 +27,10 @@ module Uplot
         OptionParser.new do |opt|
           opt.program_name = 'uplot'
           opt.version = Uplot::VERSION
-          opt.on('-O', 'outputs the standard input data to the standard output', TrueClass) do |v|
+          opt.on('-O', '--pass [VAL]', 'file to output standard input data to [stdout]') do |v|
+            @pass = v || $stdout
+          end
+          opt.on('-o', '--output VAL', 'file to output results to [stderr]') do |v|
             @output = v
           end
           opt.on('-d', '--delimiter VAL', 'use DELIM instead of TAB for field delimiter', String) do |v|