refactor: Make tape flag global

cmd/stcache/cmd/index.go

@@ -16,7 +16,6 @@ import (
 
 const (
 	dbFlag         = "db"
-	tapeFlag       = "tape"
 	recordSizeFlag = "record-size"
 	recordFlag     = "record"
 	blockFlag      = "block"
@@ -209,7 +208,6 @@ func init() {
 	workingDirDefault := filepath.Join(home, ".local", "share", "stcache", "var", "lib", "stcache")
 
 	indexCmd.PersistentFlags().StringP(dbFlag, "d", filepath.Join(workingDirDefault, "index.sqlite"), "Database to use")
-	indexCmd.PersistentFlags().StringP(tapeFlag, "t", "/dev/nst0", "Tape or tar file to read from")
 	indexCmd.PersistentFlags().IntP(recordSizeFlag, "e", 20, "Amount of 512-bit blocks per record")
 	indexCmd.PersistentFlags().IntP(recordFlag, "r", 0, "Record to seek too before counting")
 	indexCmd.PersistentFlags().IntP(blockFlag, "b", 0, "Block in record to seek too before counting")

cmd/stcache/cmd/root.go

@@ -7,6 +7,10 @@ import (
 	"github.com/spf13/viper"
 )
 
+const (
+	tapeFlag = "tape"
+)
+
 var rootCmd = &cobra.Command{
 	Use:   "stcache",
 	Short: "Simple Tape Cache",
@@ -21,6 +25,14 @@ https://github.com/pojntfx/stfs`,
 }
 
 func Execute() {
+	rootCmd.PersistentFlags().StringP(tapeFlag, "t", "/dev/nst0", "Tape or tar file to use")
+
+	if err := viper.BindPFlags(rootCmd.PersistentFlags()); err != nil {
+		panic(err)
+	}
+
+	viper.AutomaticEnv()
+
 	if err := rootCmd.Execute(); err != nil {
 		panic(err)
 	}