Combining Short Options

Traditional use of options using their shortnames look like this:

$ cmd -s -o -m "Some message"

Suppose you want users to be able to combine options with their shortnames. This can be done using the UseShortOptionHandling bool in your app configuration, or for individual commands by attaching it to the command configuration. For example:

package main

import (
    "fmt"
    "log"
    "os"

    "github.com/urfave/cli/v2"
)

func main() {
    app := &cli.App{
        UseShortOptionHandling: true,
        Commands: []*cli.Command{
            {
                Name:  "short",
                Usage: "complete a task on the list",
                Flags: []cli.Flag{
                    &cli.BoolFlag{Name: "serve", Aliases: []string{"s"}},
                    &cli.BoolFlag{Name: "option", Aliases: []string{"o"}},
                    &cli.StringFlag{Name: "message", Aliases: []string{"m"}},
                },
                Action: func(cCtx *cli.Context) error {
                    fmt.Println("serve:", cCtx.Bool("serve"))
                    fmt.Println("option:", cCtx.Bool("option"))
                    fmt.Println("message:", cCtx.String("message"))
                    return nil
                },
            },
        },
    }

    if err := app.Run(os.Args); err != nil {
        log.Fatal(err)
    }
}

If your program has any number of bool flags such as serve and option, and optionally one non-bool flag message, with the short options of -s, -o, and -m respectively, setting UseShortOptionHandling will also support the following syntax:

$ cmd -som "Some message"

If you enable UseShortOptionHandling, then you must not use any flags that have a single leading - or this will result in failures. For example, -option can no longer be used. Flags with two leading dashes (such as --options) are still valid.