feat(commands): refactor and add more commands

commands/info/du.go

@@ -0,0 +1,18 @@
+package info
+
+import (
+	"github.com/versenilvis/iris/commands/core"
+)
+
+func init() {
+	core.Register(&core.Spec{
+		Name:        "du",
+		Description: "estimate file space usage",
+		Generator:   core.FileGenerator(),
+		Options: []core.Option{
+			{Name: "-h", Description: "human readable"},
+			{Name: "-s", Description: "summarize"},
+			{Name: "-a", Description: "all files"},
+		},
+	})
+}