func saveConfig(w io.Writer, obsKeys map[string]string) {
// find flags pointing to the same variable. We will only write the longest
// named flag to the config file, the shorthand version is ignored.
deduped := make(map[flag.Value]flag.Flag)
flag.VisitAll(func(f *flag.Flag) {
if cur, ok := deduped[f.Value]; !ok || utf8.RuneCountInString(f.Name) > utf8.RuneCountInString(cur.Name) {
deduped[f.Value] = *f
}
})
flag.VisitAll(func(f *flag.Flag) {
if cur, ok := deduped[f.Value]; ok && cur.Name == f.Name {
_, usage := flag.UnquoteUsage(f)
usage = strings.Replace(usage, "\n \t", "\n# ", -1)
fmt.Fprintf(w, "\n# %s (default %v)\n", usage, f.DefValue)
fmt.Fprintf(w, "%s=%v\n", f.Name, f.Value.String())
}
})
// if we have obsolete keys left from the old config, preserve them in an
// additional section at the end of the file
if obsKeys != nil && len(obsKeys) > 0 {
fmt.Fprintln(w, "\n\n# The following options are probably deprecated and not used currently!")
for key, val := range obsKeys {
fmt.Fprintf(w, "%v=%v\n", key, val)
}
}
}
func getMethodUsage(m MethodCommand) string {
s := ""
for _, f := range m.Flags {
s += fmt.Sprintf(" -%s", f.Name)
name, usage := flag.UnquoteUsage(f)
if len(name) > 0 {
s += " " + name
}
if len(s) <= 4 {
s += "\t"
} else {
s += "\n \t"
}
s += usage
s += "\n"
}
return s
}
func formatFlag(f *flag.Flag) string {
// Two spaces before -; see next two comments.
s := fmt.Sprintf(" -%s", f.Name)
name, usage := flag.UnquoteUsage(f)
if len(name) > 0 {
s += " " + name
}
// Boolean flags of one ASCII letter are so common we
// treat them specially, putting their usage on the same line.
if len(s) <= 4 { // space, space, '-', 'x'.
s += "\t"
} else {
// Four spaces before the tab triggers good alignment
// for both 4- and 8-space tab stops.
s += "\n \t"
}
s += usage
switch f.DefValue {
case "0", "false", "":
default:
s += fmt.Sprintf(" (default %#v)", f.DefValue)
}
return s
}