From e7e467fb3a3433800f7b313d585ba33c551e2b19 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Mon, 24 Sep 2018 21:27:30 +0100
Subject: [PATCH] cmd: factor FlagName into fs.Option #2541

---
 cmd/cmd.go |  5 +----
 fs/fs.go   | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/cmd/cmd.go b/cmd/cmd.go
index 43f69f6d3..8bbd1cf95 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -447,10 +447,7 @@ func AddBackendFlags() {
 			}
 			done[opt.Name] = struct{}{}
 			// Make a flag from each option
-			name := strings.Replace(opt.Name, "_", "-", -1) // convert snake_case to kebab-case
-			if !opt.NoPrefix {
-				name = fsInfo.Prefix + "-" + name
-			}
+			name := opt.FlagName(fsInfo.Prefix)
 			found := pflag.CommandLine.Lookup(name) != nil
 			if !found {
 				// Take first line of help only
diff --git a/fs/fs.go b/fs/fs.go
index 66e2c02b0..390d9364a 100644
--- a/fs/fs.go
+++ b/fs/fs.go
@@ -154,6 +154,20 @@ func (o *Option) Type() string {
 	return reflect.TypeOf(o.value()).Name()
 }
 
+// FlagName for the option
+func (o *Option) FlagName(prefix string) string {
+	name := strings.Replace(o.Name, "_", "-", -1) // convert snake_case to kebab-case
+	if !o.NoPrefix {
+		name = prefix + "-" + name
+	}
+	return name
+}
+
+// EnvVarName for the option
+func (o *Option) EnvVarName(prefix string) string {
+	return OptionToEnv(prefix + "-" + o.Name)
+}
+
 // OptionExamples is a slice of examples
 type OptionExamples []OptionExample