| package flags |
| |
| import ( |
| "strings" |
| ) |
| |
| // Windows uses a front slash for both short and long options. Also it uses |
| // a colon for name/argument delimter. |
| const ( |
| defaultShortOptDelimiter = '/' |
| defaultLongOptDelimiter = "/" |
| defaultNameArgDelimiter = ':' |
| ) |
| |
| func argumentIsOption(arg string) bool { |
| // Windows-style options allow front slash for the option |
| // delimiter. |
| return len(arg) > 0 && (arg[0] == '-' || arg[0] == '/') |
| } |
| |
| // stripOptionPrefix returns the option without the prefix and whether or |
| // not the option is a long option or not. |
| func stripOptionPrefix(optname string) (string, bool) { |
| // Determine if the argument is a long option or not. Windows |
| // typically supports both long and short options with a single |
| // front slash as the option delimiter, so handle this situation |
| // nicely. |
| if strings.HasPrefix(optname, "--") { |
| return optname[2:], true |
| } else if strings.HasPrefix(optname, "-") { |
| return optname[1:], false |
| } else if strings.HasPrefix(optname, "/") { |
| optname = optname[1:] |
| if len(optname) > 1 { |
| return optname, true |
| } |
| return optname, false |
| } |
| |
| return optname, false |
| } |
| |
| // splitOption attempts to split the passed option into a name and an argument. |
| // When there is no argument specified, nil will be returned for it. |
| func splitOption(option string) (string, *string) { |
| if len(option) == 0 { |
| return option, nil |
| } |
| |
| // Windows typically uses a colon for the option name and argument |
| // delimiter while POSIX typically uses an equals. Support both styles, |
| // but don't allow the two to be mixed. That is to say /foo:bar and |
| // --foo=bar are acceptable, but /foo=bar and --foo:bar are not. |
| var pos int |
| if option[0] == '/' { |
| pos = strings.Index(option, ":") |
| } else if option[0] == '-' { |
| pos = strings.Index(option, "=") |
| } |
| |
| if pos >= 0 { |
| rest := option[pos+1:] |
| return option[:pos], &rest |
| } |
| |
| return option, nil |
| } |
| |
| // newHelpGroup returns a new group that contains default help parameters. |
| func newHelpGroup(showHelp func() error) *Group { |
| // Windows CLI applications typically use /? for help, so make both |
| // that available as well as the POSIX style h and help. |
| var help struct { |
| ShowHelp func() error `short:"?" description:"Show this help message"` |
| ShowHelp2 func() error `short:"h" long:"help" description:"Show this help message"` |
| } |
| help.ShowHelp = showHelp |
| help.ShowHelp2 = showHelp |
| return NewGroup("Help Options", &help) |
| } |