Improve suggestions - prefix will match

command.go

@@ -429,33 +429,37 @@ func (c *Command) Find(args []string) (*Command, []string, error) {
 
 	// root command with subcommands, do subcommand checking
 	if commandFound == c && len(argsWOflags) > 0 {
-		suggestions := ""
+		suggestionsString := ""
 		if !c.DisableSuggestions {
 			if c.SuggestionsMinimumDistance <= 0 {
 				c.SuggestionsMinimumDistance = 2
 			}
-			similar := []string{}
-			for _, cmd := range c.commands {
-				if cmd.IsAvailableCommand() {
-					levenshtein := ld(argsWOflags[0], cmd.Name(), true)
-					if levenshtein <= c.SuggestionsMinimumDistance {
-						similar = append(similar, cmd.Name())
-					}
-				}
-			}
-			if len(similar) > 0 {
-				suggestions += "\n\nDid you mean this?\n"
-				for _, s := range similar {
-					suggestions += fmt.Sprintf("\t%v\n", s)
+			if suggestions := c.SuggestionsFor(argsWOflags[0]); len(suggestions) > 0 {
+				suggestionsString += "\n\nDid you mean this?\n"
+				for _, s := range suggestions {
+					suggestionsString += fmt.Sprintf("\t%v\n", s)
 				}
 			}
 		}
-		return commandFound, a, fmt.Errorf("unknown command %q for %q%s", argsWOflags[0], commandFound.CommandPath(), suggestions)
+		return commandFound, a, fmt.Errorf("unknown command %q for %q%s", argsWOflags[0], commandFound.CommandPath(), suggestionsString)
 	}
 
 	return commandFound, a, nil
 }
 
+func (c *Command) SuggestionsFor(cmdName string) []string {
+	suggestions := []string{}
+	for _, cmd := range c.commands {
+		if cmd.IsAvailableCommand() {
+			levenshtein := ld(cmdName, cmd.Name(), true)
+			if levenshtein <= c.SuggestionsMinimumDistance || strings.HasPrefix(strings.ToLower(cmd.Name()), strings.ToLower(cmdName)) {
+				suggestions = append(suggestions, cmd.Name())
+			}
+		}
+	}
+	return suggestions
+}
+
 func (c *Command) Root() *Command {
 	var findRoot func(*Command) *Command