update argv code

Signed-off-by: Jeff Carr <jcarr@wit.com>

Makefile

@@ -1,5 +1,13 @@
+VERSION = $(shell git describe --tags)
+
 all:
-	GO111MODULE=off go build -v -x
+	GO111MODULE=off go build -v -x \
+		    -ldflags "-X main.VERSION=${VERSION}"
+	./helloworld
+
+install:
+	GO111MODULE=off go install -v -x \
+		    -ldflags "-X main.VERSION=${VERSION}"
 	./helloworld
 
 gocui:

argv.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"os"
+
+	"github.com/alexflint/go-arg"
+)
+
+/*
+	this parses the command line arguements
+
+	this enables command line options from other packages like 'gui' and 'log'
+*/
+
+var argv args
+
+type args struct {
+	Demo      string `arg:"positional"                   help:"this is just a demo"`
+}
+
+func (a args) Description() string {
+	return `
+This helloworld example demonstrates the 'gui' plugin toolkits
+`
+}
+
+func init() {
+	pp := arg.MustParse(&argv)
+
+	// for very new users or users unfamilar with the command line, this may help them
+	if argv.Demo == "version" || argv.Demo == "help" || argv.Demo == "?" {
+		pp.WriteHelp(os.Stdout)
+		os.Exit(0)
+	}
+}
+
+func (args) Version() string {
+	return "helloworld " + VERSION
+}

debugger.go

@@ -5,17 +5,11 @@ package main
 */
 
 import (
-	"go.wit.com/dev/alexflint/arg"
 	"go.wit.com/lib/debugger"
 	"go.wit.com/log"
 )
 
-var args struct {
-}
-
 func init() {
-	arg.MustParse(&args)
-
 	if debugger.ArgDebug() {
 		log.Info("cmd line --debugger == true")
 		go func() {

main.go

@@ -1,4 +1,3 @@
-// This creates a simple helloworld window
 package main
 
 import (
@@ -6,6 +5,9 @@ import (
 	"go.wit.com/log"
 )
 
+// sent from -ldflags
+var VERSION string
+
 // This is the beginning of our binary tree of widgets
 var myGui *gui.Node