Pull in go-flags, modified to build on Solaris

github.com/jessevdk/go-flags/option.go

@@ -0,0 +1,95 @@
+package flags
+
+import (
+	"fmt"
+	"reflect"
+	"unicode/utf8"
+)
+
+// Option flag information. Contains a description of the option, short and
+// long name as well as a default value and whether an argument for this
+// flag is optional.
+type Option struct {
+	// The description of the option flag. This description is shown
+	// automatically in the builtin help.
+	Description string
+
+	// The short name of the option (a single character). If not 0, the
+	// option flag can be 'activated' using -<ShortName>. Either ShortName
+	// or LongName needs to be non-empty.
+	ShortName rune
+
+	// The long name of the option. If not "", the option flag can be
+	// activated using --<LongName>. Either ShortName or LongName needs
+	// to be non-empty.
+	LongName string
+
+	// The default value of the option.
+	Default []string
+
+	// If true, specifies that the argument to an option flag is optional.
+	// When no argument to the flag is specified on the command line, the
+	// value of Default will be set in the field this option represents.
+	// This is only valid for non-boolean options.
+	OptionalArgument bool
+
+	// The optional value of the option. The optional value is used when
+	// the option flag is marked as having an OptionalArgument. This means
+	// that when the flag is specified, but no option argument is given,
+	// the value of the field this option represents will be set to
+	// OptionalValue. This is only valid for non-boolean options.
+	OptionalValue []string
+
+	// If true, the option _must_ be specified on the command line. If the
+	// option is not specified, the parser will generate an ErrRequired type
+	// error.
+	Required bool
+
+	// A name for the value of an option shown in the Help as --flag [ValueName]
+	ValueName string
+
+	// A mask value to show in the help instead of the default value. This
+	// is useful for hiding sensitive information in the help, such as
+	// passwords.
+	DefaultMask string
+
+	// The struct field which the option represents.
+	field reflect.StructField
+
+	// The struct field value which the option represents.
+	value reflect.Value
+
+	defaultValue reflect.Value
+	iniUsedName  string
+	tag          multiTag
+}
+
+// String converts an option to a human friendly readable string describing the
+// option.
+func (option *Option) String() string {
+	var s string
+	var short string
+
+	if option.ShortName != 0 {
+		data := make([]byte, utf8.RuneLen(option.ShortName))
+		utf8.EncodeRune(data, option.ShortName)
+		short = string(data)
+
+		if len(option.LongName) != 0 {
+			s = fmt.Sprintf("%s%s, %s%s",
+				string(defaultShortOptDelimiter), short,
+				defaultLongOptDelimiter, option.LongName)
+		} else {
+			s = fmt.Sprintf("%s%s", string(defaultShortOptDelimiter), short)
+		}
+	} else if len(option.LongName) != 0 {
+		s = fmt.Sprintf("%s%s", defaultLongOptDelimiter, option.LongName)
+	}
+
+	return s
+}
+
+// Value returns the option value as an interface{}.
+func (option *Option) Value() interface{} {
+	return option.value.Interface()
+}