add initial Cli module

lib/gcovinator/cli.rb

@@ -0,0 +1,47 @@
+require "gcovinator"
+require "optparse"
+
+module Gcovinator
+  module Cli
+
+    class << self
+      def run(argv)
+        argv = argv.dup
+        build_dir = "."
+        source_dirs = []
+
+        OptionParser.new do |opts|
+
+          opts.banner = "Usage: #{$0} [options] [FILES]"
+
+          opts.separator ""
+          opts.separator "Pass paths to .gcda files as FILES."
+          opts.separator "If no FILES are specified, gcovinator looks for all .gcda files recursively under the build directory"
+          opts.separator ""
+          opts.separator "Options:"
+
+          opts.on("-b BUILDDIR", "--build-dir BUILDDIR", "Specify the build directory. Source file paths in object/gcov files will be relative to this directory. Defaults to '.' if not specified.") do |b|
+            build_dir = b
+          end
+
+          opts.on("-s SRCDIR", "--source-dir SRCDIR", "Specify a source directory. Reports will only be generated for sources under a specified source directory. Multiple source directories may be specified. Defaults to '.' if not specified.") do |s|
+            source_dirs << s
+          end
+
+          opts.on_tail("--version", "Show version") do
+            puts "gcovinator, version #{Gcovinator::VERSION}"
+            exit 0
+          end
+
+          opts.on_tail("-h", "--help", "Show this help.") do
+            puts opts
+            exit 0
+          end
+
+        end.parse!(argv)
+
+      end
+    end
+
+  end
+end