Print out usage in the proper POSIX format

1 files changed, 8 insertions, 3 deletions

diff --git a/flag.go b/flag.go
index 08970a4..014f98b 100644
--- a/flag.go
+++ b/flag.go
@@ -337,12 +337,17 @@ func Set(name, value string) error {
 // otherwise, the default values of all defined flags in the set.
 func (f *FlagSet) PrintDefaults() {
 	f.VisitAll(func(flag *Flag) {
-		format := "  -%s=%s: %s\n"
+		format := "  --%s=%s: %s\n"
 		if _, ok := flag.Value.(*stringValue); ok {
 			// put quotes on the value
-			format = "  -%s=%q: %s\n"
+			format = "  --%s=%q: %s\n"
 		}
-		fmt.Fprintf(f.out(), format, flag.Name, flag.DefValue, flag.Usage)
+		if len(flag.Shortcut) > 0 {
+			format = "  -%s," + format[1:]
+		} else {
+			format = "%s" + format
+		}
+		fmt.Fprintf(f.out(), format, flag.Shortcut, flag.Name, flag.DefValue, flag.Usage)
 	})
 }