add instance command

cmd/mstdn/cmd_instance.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/mattn/go-mastodon"
+	"github.com/urfave/cli"
+)
+
+func cmdInstance(c *cli.Context) error {
+	client := c.App.Metadata["client"].(*mastodon.Client)
+	instance, err := client.GetInstance()
+	if err != nil {
+		return err
+	}
+	fmt.Printf("URI        : %s\n", instance.URI)
+	fmt.Printf("Title      : %s\n", instance.Title)
+	fmt.Printf("Description: %s\n", instance.Description)
+	fmt.Printf("EMail      : %s\n", instance.EMail)
+	return nil
+}

cmd/mstdn/main.go

@@ -197,6 +197,11 @@ func run() int {
 			Usage:  "show notification",
 			Action: cmdNotification,
 		},
+		{
+			Name:   "instance",
+			Usage:  "show instance information",
+			Action: cmdInstance,
+		},
 	}
 	app.Run(os.Args)
 	return 0