package flag
Value is the interface to the dynamic value stored in a flag. (The default value is represented as a string.)
If a Value has an IsBoolFlag() bool method returning true, the command-line parser makes -name equivalent to -name=true rather than using the next command-line argument.
Golang flag.Value type usage examples
func lookupStringSlice(name string, set *flag.FlagSet) []string {
f := set.Lookup(name)
if f != nil {
return (f.Value.(*StringSlice)).Value()
}
return nil
}
func lookupIntSlice(name string, set *flag.FlagSet) []int {
f := set.Lookup(name)
if f != nil {
return (f.Value.(*IntSlice)).Value()
}
return nil
}
func lookupGeneric(name string, set *flag.FlagSet) interface{} {
f := set.Lookup(name)
if f != nil {
return f.Value
}
return nil
}
func lookupBool(name string, set *flag.FlagSet) bool {
f := set.Lookup(name)
if f != nil {
val, err := strconv.ParseBool(f.Value.String())
if err != nil {
return false
}
return val
}
return false
}
Reference :
http://golang.org/pkg/flag/#Value
