diff options
Diffstat (limited to 'src/flag/flag.go')
| -rw-r--r-- | src/flag/flag.go | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/src/flag/flag.go b/src/flag/flag.go index de2d91f8b1..323e452a83 100644 --- a/src/flag/flag.go +++ b/src/flag/flag.go @@ -406,6 +406,7 @@ func defaultUsage(f *FlagSet) { // for how to write your own usage function. // Usage prints to standard error a usage message documenting all defined command-line flags. +// It is called when an error occurs while parsing flags. // The function is a variable that may be changed to point to a custom function. var Usage = func() { fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0]) @@ -702,13 +703,15 @@ func (f *FlagSet) failf(format string, a ...interface{}) error { return err } -// usage calls the Usage method for the flag set, or the usage function if -// the flag set is CommandLine. +// usage calls the Usage method for the flag set if one is specified, +// or the appropriate default usage function otherwise. func (f *FlagSet) usage() { - if f == CommandLine { - Usage() - } else if f.Usage == nil { - defaultUsage(f) + if f.Usage == nil { + if f == CommandLine { + Usage() + } else { + defaultUsage(f) + } } else { f.Usage() } |