Better command args parsing and help

go.mod

@@ -1,3 +1,8 @@
 module github.com/mercury2269/sqsmover
 
-require github.com/aws/aws-sdk-go v1.15.76
+require (
+	github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc // indirect
+	github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf // indirect
+	github.com/aws/aws-sdk-go v1.15.76
+	gopkg.in/alecthomas/kingpin.v2 v2.2.6
+)

go.sum

@@ -1,4 +1,10 @@
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc h1:cAKDfWh5VpdgMhJosfJnn5/FoN2SRZ4p7fJNX58YPaU=
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/aws/aws-sdk-go v1.15.76 h1:AZB4clNWIk13YJaTm07kqyrHkj7gZYBQCgyTh/v4Sec=
 github.com/aws/aws-sdk-go v1.15.76/go.mod h1:E3/ieXAlvM0XWO57iftYVDLLvQ824smPP3ATZkfNZeM=
 github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8 h1:12VvqtR6Aowv3l/EQUlocDHW2Cp4G9WJVH7uyH8QFJE=
 github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=

main.go

@@ -1,13 +1,22 @@
 package main
 
 import (
-	"flag"
 	"fmt"
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/sqs"
+	"gopkg.in/alecthomas/kingpin.v2"
 )
 
+var (
+	// app              = kingpin.New("sqsmover", "A command line application that moves messages between AWS SQS queues")
+	sourceQueue      = kingpin.Flag("source", "Source queue to move messages from").Short('s').Required().String()
+	destinationQueue = kingpin.Flag("destination", "Destination queue to move messages to").Short('d').Required().String()
+	region			= kingpin.Flag("region", "AWS Region for source and destination queues").Short('r').Default("us-west-2").String()
+)
+
+
+
 func resolveQueueUrl(queueName string, svc *sqs.SQS) (error, string) {
 	params := &sqs.GetQueueUrlInput{
 		QueueName: aws.String(queueName),
@@ -25,27 +34,19 @@ func resolveQueueUrl(queueName string, svc *sqs.SQS) (error, string) {
 }
 
 func main() {
+	kingpin.UsageTemplate(kingpin.CompactUsageTemplate)
 
-	var (
-		sourceQueueName = flag.String("source", "", "Source queue name")
-		destQueueName   = flag.String("dest", "", "Destination queue name")
-		region   = flag.String("region", "us-west-2", "AWS region")
-	)
-
-	flag.Parse()
+	kingpin.Parse()
 
-	// Create an EC2 service object in the "us-west-2" region
-	// Note that you can also configure your region globally by
-	// exporting the AWS_REGION environment variable
 	svc := sqs.New(session.New(), aws.NewConfig().WithRegion(*region))
 
-	err, sourceUrl := resolveQueueUrl(*sourceQueueName, svc)
+	err, sourceUrl := resolveQueueUrl(*sourceQueue, svc)
 
 	if err != nil {
 		return
 	}
 
-	err, destUrl := resolveQueueUrl(*destQueueName, svc)
+	err, destUrl := resolveQueueUrl(*destinationQueue, svc)
 
 	if err != nil {
 		return