Added cli niceness

yaml.go

@@ -5,10 +5,32 @@ import (
   "gopkg.in/yaml.v2"
   "log"
   "io/ioutil"
+  "os"
+  "github.com/codegangsta/cli"
 )
 
 func main() {
-  var raw_data, read_error = ioutil.ReadFile("sample.yaml")
+  app := cli.NewApp()
+  app.Name = "yaml"
+  app.Usage = "command line tool for reading and writing yaml"
+  app.Commands = []cli.Command{
+    {
+      Name:      "read",
+      Aliases:     []string{"r"},
+      Usage:     "(default) reads a property from a given yaml file",
+      Action:   read_file,
+    },
+  }
+  app.Action = read_file
+  app.Run(os.Args)
+}
+
+func read_file(c *cli.Context) {
+  if len(c.Args()) == 0 {
+    log.Fatalf("Must provide filename")
+  }
+  var filename = c.Args()[0]
+  var raw_data, read_error = ioutil.ReadFile(filename)
 
   if read_error != nil {
     log.Fatalf("error: %v", read_error)