be more colorful - close #41

lib/rscons/ansi.rb

@@ -0,0 +1,52 @@
+module Rscons
+  module Ansi
+    class << self
+
+      # Write a message to an IO with ANSI escape codes.
+      #
+      # @param io [IO]
+      #   The IO to write to.
+      # @param message [Array<String, Symbol>]
+      #   Strings to be printed, with Symbols representing ANSI escape codes.
+      #
+      # @return [void]
+      def write(io, *message)
+        do_color = Rscons.do_ansi_color
+        if do_color.nil?
+          do_color = do_ansi?(io)
+        end
+        out = ""
+        message.each do |m|
+          if m.is_a?(String)
+            out += m
+          elsif do_color
+            case m
+            when :red
+              out += "\e[0;31m"
+            when :cyan
+              out += "\e[0;36m"
+            when :reset
+              out += "\e[0m"
+            end
+          end
+        end
+        io.write(out)
+      end
+
+      private
+
+      # Determine whether to output ANSI color escape codes.
+      #
+      # @return [Boolean]
+      #   Whether to output ANSI color escape codes.
+      def do_ansi?(io)
+        if RUBY_PLATFORM =~ /mingw/
+          (ENV["TERM"] == "xterm") && %w[fifo characterSpecial].include?(io.stat.ftype)
+        else
+          io.tty?
+        end
+      end
+
+    end
+  end
+end

lib/rscons/cli.rb

@@ -39,6 +39,15 @@ module Rscons
             Rscons.n_threads = n_threads.to_i
           end
 
+          opts.on("-r", "--color MODE", "Set color mode (off, auto, force)") do |color_mode|
+            case color_mode
+            when "off"
+              Rscons.do_ansi_color = false
+            when "force"
+              Rscons.do_ansi_color = true
+            end
+          end
+
           opts.on_tail("--version", "Show version") do
             puts "Rscons version #{Rscons::VERSION}"
             exit 0

lib/rscons/environment.rb

@@ -331,7 +331,7 @@ module Rscons
                                  setup_info: job[:setup_info])
             unless result
               failure = "Failed to build #{job[:target]}"
-              $stderr.puts failure
+              Ansi.write($stderr, :red, failure, :reset, "\n")
               next
             end
           end
@@ -358,10 +358,10 @@ module Rscons
               end
             else
               unless @echo == :command
-                $stdout.puts "Failed command was: #{command_to_s(tc.command)}"
+                print_failed_command(tc.command)
               end
               failure = "Failed to build #{tc.build_operation[:target]}"
-              $stderr.puts failure
+              Ansi.write($stderr, :red, failure, :reset, "\n")
               break
             end
           end
@@ -412,16 +412,12 @@ module Rscons
     #
     # @return [true,false,nil] Return value from Kernel.system().
     def execute(short_desc, command, options = {})
-      if @echo == :command
-        puts command_to_s(command)
-      elsif @echo == :short
-        puts short_desc
-      end
+      print_builder_run_message(short_desc, command)
       env_args = options[:env] ? [options[:env]] : []
       options_args = options[:options] ? [options[:options]] : []
       system(*env_args, *Rscons.command_executer, *command, *options_args).tap do |result|
         unless result or @echo == :command
-          $stdout.puts "Failed command was: #{command_to_s(command)}"
+          print_failed_command(command)
         end
       end
     end
@@ -657,7 +653,7 @@ module Rscons
             call_build_hooks[:post]
           else
             unless @echo == :command
-              $stdout.puts "Failed command was: #{command_to_s(tc.command)}"
+              print_failed_command(tc.command)
             end
           end
         end
@@ -844,7 +840,7 @@ module Rscons
       varset_hash = @varset.to_h
       varset_hash.keys.sort_by(&:to_s).each do |var|
         var_str = var.is_a?(Symbol) ? var.inspect : var
-        puts "#{var_str} => #{varset_hash[var].inspect}"
+        Ansi.write($stdout, :cyan, var_str, :reset, " => #{varset_hash[var].inspect}\n")
       end
     end
 
@@ -857,6 +853,34 @@ module Rscons
       @n_threads || Rscons.n_threads
     end
 
+    # Print the builder run message, depending on the Environment's echo mode.
+    #
+    # @param short_description [String]
+    #   Builder short description, printed if the echo mode is :short.
+    # @param command [Array<String>]
+    #   Builder command, printed if the echo mode is :command.
+    #
+    # @return [void]
+    def print_builder_run_message(short_description, command)
+      case @echo
+      when :command
+        message = command_to_s(command) if command
+      when :short
+        message = short_description if short_description
+      end
+      Ansi.write($stdout, :cyan, message, :reset, "\n") if message
+    end
+
+    # Print a failed command.
+    #
+    # @param command [Array<String>]
+    #   Builder command.
+    #
+    # @return [void]
+    def print_failed_command(command)
+      Ansi.write($stdout, :red, "Failed command was: #{command_to_s(command)}", :reset, "\n")
+    end
+
     private
 
     # Add a build target.
@@ -889,13 +913,7 @@ module Rscons
     #
     # @return [void]
     def start_threaded_command(tc)
-      if @echo == :command
-        puts command_to_s(tc.command)
-      elsif @echo == :short
-        if tc.short_description
-          puts tc.short_description
-        end
-      end
+      print_builder_run_message(tc.short_description, tc.command)
 
       env_args = tc.system_env ? [tc.system_env] : []
       options_args = tc.system_options ? [tc.system_options] : []