Merge pull request #137 from alexflint/optional-long

Optional long names

1 files changed, 41 insertions, 15 deletions

diff --git a/usage.go b/usage.go
index 776ac03..cbbb021 100644
--- a/usage.go
+++ b/usage.go
@@ -36,12 +36,15 @@ func (p *Parser) WriteUsage(w io.Writer) {
 
 // writeUsageForCommand writes usage information for the given subcommand
 func (p *Parser) writeUsageForCommand(w io.Writer, cmd *command) {
-	var positionals, options []*spec
+	var positionals, longOptions, shortOptions []*spec
 	for _, spec := range cmd.specs {
-		if spec.positional {
+		switch {
+		case spec.positional:
 			positionals = append(positionals, spec)
-		} else {
-			options = append(options, spec)
+		case spec.long != "":
+			longOptions = append(longOptions, spec)
+		case spec.short != "":
+			shortOptions = append(shortOptions, spec)
 		}
 	}
 
@@ -64,7 +67,19 @@ func (p *Parser) writeUsageForCommand(w io.Writer, cmd *command) {
 	}
 
 	// write the option component of the usage message
-	for _, spec := range options {
+	for _, spec := range shortOptions {
+		// prefix with a space
+		fmt.Fprint(w, " ")
+		if !spec.required {
+			fmt.Fprint(w, "[")
+		}
+		fmt.Fprint(w, synopsis(spec, "-"+spec.short))
+		if !spec.required {
+			fmt.Fprint(w, "]")
+		}
+	}
+
+	for _, spec := range longOptions {
 		// prefix with a space
 		fmt.Fprint(w, " ")
 		if !spec.required {
@@ -144,12 +159,15 @@ func (p *Parser) WriteHelp(w io.Writer) {
 
 // writeHelp writes the usage string for the given subcommand
 func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
-	var positionals, options []*spec
+	var positionals, longOptions, shortOptions []*spec
 	for _, spec := range cmd.specs {
-		if spec.positional {
+		switch {
+		case spec.positional:
 			positionals = append(positionals, spec)
-		} else {
-			options = append(options, spec)
+		case spec.long != "":
+			longOptions = append(longOptions, spec)
+		case spec.short != "":
+			shortOptions = append(shortOptions, spec)
 		}
 	}
 
@@ -166,10 +184,13 @@ func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
 		}
 	}
 
-	// write the list of options
-	if len(options) > 0 || cmd.parent == nil {
+	// write the list of options with the short-only ones first to match the usage string
+	if len(shortOptions)+len(longOptions) > 0 || cmd.parent == nil {
 		fmt.Fprint(w, "\nOptions:\n")
-		for _, spec := range options {
+		for _, spec := range shortOptions {
+			p.printOption(w, spec)
+		}
+		for _, spec := range longOptions {
 			p.printOption(w, spec)
 		}
 	}
@@ -215,11 +236,16 @@ func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
 }
 
 func (p *Parser) printOption(w io.Writer, spec *spec) {
-	left := synopsis(spec, "--"+spec.long)
+	ways := make([]string, 0, 2)
+	if spec.long != "" {
+		ways = append(ways, synopsis(spec, "--"+spec.long))
+	}
 	if spec.short != "" {
-		left += ", " + synopsis(spec, "-"+spec.short)
+		ways = append(ways, synopsis(spec, "-"+spec.short))
+	}
+	if len(ways) > 0 {
+		printTwoCols(w, strings.Join(ways, ", "), spec.help, spec.defaultVal, spec.env)
 	}
-	printTwoCols(w, left, spec.help, spec.defaultVal, spec.env)
 }
 
 func synopsis(spec *spec, form string) string {