squash merge from dev branch

vendor/gopkg.in/alecthomas/kingpin.v2/_examples/completion/main.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/alecthomas/kingpin"
+)
+
+func listHosts() []string {
+	// Provide a dynamic list of hosts from a hosts file or otherwise
+	// for bash completion. In this example we simply return static slice.
+
+	// You could use this functionality to reach into a hosts file to provide
+	// completion for a list of known hosts.
+	return []string{"sshhost.example", "webhost.example", "ftphost.example"}
+}
+
+type NetcatCommand struct {
+	hostName string
+	port     int
+	format   string
+}
+
+func (n *NetcatCommand) run(c *kingpin.ParseContext) error {
+	fmt.Printf("Would have run netcat to hostname %v, port %d, and output format %v\n", n.hostName, n.port, n.format)
+	return nil
+}
+
+func configureNetcatCommand(app *kingpin.Application) {
+	c := &NetcatCommand{}
+	nc := app.Command("nc", "Connect to a Host").Action(c.run)
+	nc.Flag("nop-flag", "Example of a flag with no options").Bool()
+
+	// You can provide hint options using a function to generate them
+	nc.Flag("host", "Provide a hostname to nc").
+		Required().
+		HintAction(listHosts).
+		StringVar(&c.hostName)
+
+	// You can provide hint options statically
+	nc.Flag("port", "Provide a port to connect to").
+		Required().
+		HintOptions("80", "443", "8080").
+		IntVar(&c.port)
+
+	// Enum/EnumVar options will be turned into completion options automatically
+	nc.Flag("format", "Define the output format").
+		Default("raw").
+		EnumVar(&c.format, "raw", "json")
+
+	// You can combine HintOptions with HintAction too
+	nc.Flag("host-with-multi", "Define a hostname").
+		HintAction(listHosts).
+		HintOptions("myhost.com").
+		String()
+
+	// And combine with themselves
+	nc.Flag("host-with-multi-options", "Define a hostname").
+		HintOptions("myhost.com").
+		HintOptions("myhost2.com").
+		String()
+
+	// If you specify HintOptions/HintActions for Enum/EnumVar, the options
+	// provided for Enum/EnumVar will be overridden.
+	nc.Flag("format-with-override-1", "Define a format").
+		HintAction(listHosts).
+		Enum("option1", "option2")
+
+	nc.Flag("format-with-override-2", "Define a format").
+		HintOptions("myhost.com", "myhost2.com").
+		Enum("option1", "option2")
+}
+
+func addSubCommand(app *kingpin.Application, name string, description string) {
+	c := app.Command(name, description).Action(func(c *kingpin.ParseContext) error {
+		fmt.Printf("Would have run command %s.\n", name)
+		return nil
+	})
+	c.Flag("nop-flag", "Example of a flag with no options").Bool()
+}
+
+func main() {
+	app := kingpin.New("completion", "My application with bash completion.")
+	app.Flag("flag-1", "").String()
+	app.Flag("flag-2", "").HintOptions("opt1", "opt2").String()
+
+	configureNetcatCommand(app)
+
+	// Add some additional top level commands
+	addSubCommand(app, "ls", "Additional top level command to show command completion")
+	addSubCommand(app, "ping", "Additional top level command to show command completion")
+	addSubCommand(app, "nmap", "Additional top level command to show command completion")
+
+	kingpin.MustParse(app.Parse(os.Args[1:]))
+}