Case insensitive commands/sub-commands?

[stevewi-niteflyte]

Is there a way to do this? It's some measure of protection against fat-finger Caps-Lock incidents... ;-)

[pballada]

There's no built-in flag for it. Matching is exact (HasName is slices.Contains(cmd.Names(), name)), but v3 has a hook in exactly the right place: SuggestCommandFunc.

In command_run.go, before looking up the subcommand, the command does this:

name := cmd.parsedArgs.First()
if cmd.SuggestCommandFunc != nil && name != "--" {
    name = cmd.SuggestCommandFunc(cmd.Commands, name)
}
subCmd = cmd.Command(name)

So whatever your function returns is the name used for the lookup. Map the typed name to the real one, ignoring case:

import (
    "context"
    "os"
    "strings"

    "github.com/urfave/cli/v3"
)

func caseInsensitiveCommand(commands []*cli.Command, provided string) string {
    for _, c := range commands {
        for _, n := range c.Names() { // Name + Aliases
            if strings.EqualFold(n, provided) {
                return n
            }
        }
    }
    return provided // unknown: leave it alone, so CommandNotFound / default command still work
}

// The hook is per command, so set it on every level.
func withCaseInsensitiveCommands(cmd *cli.Command) *cli.Command {
    cmd.SuggestCommandFunc = caseInsensitiveCommand
    for _, sub := range cmd.Commands {
        withCaseInsensitiveCommands(sub)
    }
    return cmd
}

func main() {
    root := withCaseInsensitiveCommands(&cli.Command{
        Name:     "app",
        Commands: []*cli.Command{ /* ... */ },
    })
    _ = root.Run(context.Background(), os.Args)
}

APP SERVE, Serve and serve then all run serve.

Two details:

• Set it on every command. SuggestCommandFunc isn't inherited, because each command checks its own field. That's why the helper walks the tree.
• It replaces prefix matching. PrefixMatchCommands: true only installs its own default (cli.SuggestCommand, a Jaro-Winkler match) when SuggestCommandFunc is nil. If you want both, fall back to it instead of returning provided: return cli.SuggestCommand(commands, provided). Be aware that it always returns the closest name, so typos then run the nearest command rather than failing.

Flags are separate. Their names are still matched exactly. Upper-case -V versus -v is usually intentional there, so I'd leave flags alone.

[stevewi-niteflyte]

Thanks for the info. Maybe I'll do this later... It's kind of unimportant at the moment...half my app is unwritten.