add main cxl.rb, Cxl::VERSION, and initial CLI processing

bin/cxlc

@@ -5,6 +5,6 @@ $LOAD_PATH << "#{lib_dir}/cxl/lib"
 $LOAD_PATH << "#{lib_dir}/yawpa/lib"
 $LOAD_PATH << "#{lib_dir}/whittle/lib"
 
-require "cxl/cli"
+require "cxl"
 
 exit(Cxl::Cli.run(ARGV.dup))

lib/cxl/cxl/lib/cxl.rb

@@ -0,0 +1,2 @@
+require "cxl/cli"
+require "cxl/version"

lib/cxl/cxl/lib/cxl/cli.rb

@@ -2,10 +2,33 @@ module Cxl
   class Cli
     class << self
 
+      HELP_TEXT = <<EOF
+Usage: clxc [options] <input-files...> -- <C-compiler-flags>
+  Options:
+    --version     show version and exit
+    --help, -h    show this help and exit
+    -c            compile only (no link)
+    -o OUTPUT     send output to file OUTPUT
+EOF
+
       def run(params)
         require "yawpa"
 
-        puts "Coming soon..."
+        options = {
+          version: {},
+          help: {short: "h"},
+          compile_only: {short: "c"},
+          output: {short: "o", nargs: 1},
+        }
+        opts, args = Yawpa.parse(params, options, posix_order: true)
+        if opts[:version]
+          puts "clxc, version #{Cxl::VERSION}"
+          return 0
+        end
+        if opts[:help]
+          puts HELP_TEXT
+          return 0
+        end
 
         0
       end

lib/cxl/cxl/lib/cxl/version.rb

@@ -0,0 +1,3 @@
+module Cxl
+  VERSION = "0.0.1"
+end