Pull in go-flags, modified to build on Solaris

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

@@ -0,0 +1,85 @@
+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) (prefix string, name string, islong 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.
+	possplit := 0
+
+	if strings.HasPrefix(optname, "--") {
+		possplit = 2
+		islong = true
+	} else if strings.HasPrefix(optname, "-") {
+		possplit = 1
+		islong = false
+	} else if strings.HasPrefix(optname, "/") {
+		possplit = 1
+		islong = len(optname) > 2
+	}
+
+	return optname[:possplit], optname[possplit:], islong
+}
+
+// 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(prefix string, option string, islong bool) (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 prefix == "/" {
+		pos = strings.Index(option, ":")
+	} else if len(prefix) > 0 {
+		pos = strings.Index(option, "=")
+	}
+
+	if (islong && pos >= 0) || (!islong && pos == 1) {
+		rest := option[pos+1:]
+		return option[:pos], &rest
+	}
+
+	return option, nil
+}
+
+// addHelpGroup adds a new group that contains default help parameters.
+func (c *Command) addHelpGroup(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 {
+		ShowHelpWindows func() error `short:"?" description:"Show this help message"`
+		ShowHelpPosix   func() error `short:"h" long:"help" description:"Show this help message"`
+	}
+
+	help.ShowHelpWindows = showHelp
+	help.ShowHelpPosix = showHelp
+
+	ret, _ := c.AddGroup("Help Options", "", &help)
+	return ret
+}