Command: Presetting Args

Injecting args to a command

.PresetCmdLines(args...) can be used to provide presetting args for a command. These args will be injected into the tail of the command, which need not inputed by end-user.

For instence, supposing a subcmd preset/cmd has preset args -pv，then the inputing app preset cmd would be treated as app preset cmd -p -v.

Definitions

The examples/demo/ showes howto using Preset Args, in cmd/preset.go:

package main
 
import (
	"context"
	"os"
 
	"github.com/hedzr/cmdr/v2"
	"github.com/hedzr/cmdr/v2/cli"
	"github.com/hedzr/cmdr/v2/examples/cmd"
	logz "github.com/hedzr/logg/slog"
)
 
const (
	appName = "demo-app"
	desc    = ``
	version = cmdr.Version
	author  = ``
)
 
func main() {
	app := cmdr.Create(appName, version, author, desc).
    With(func(app cli.App) {
	  }).
    WithAdders(cmd.Commands...).
    Build()
 
	ctx := context.Background()
	if err := app.Run(ctx); err != nil {
		logz.ErrorContext(ctx, "Application Error:", "err", err) // stacktrace if in debug mode/build
		os.Exit(app.SuggestRetCode())
	} else if rc := app.SuggestRetCode(); rc != 0 {
		os.Exit(rc)
	}
}

Run

The result of the example app is,

$ go run ./examples/demo preset cmd
demo-app v2.1.0 ~ Copyright © 2025 by demo-app Authors ~ All Rights Reserved.
 
Usage:
 
  $ demo-app preset cmd [Options...][files...]
 
Parent Flags (Cmd{'preset'}):
  -p, --preset                                preset arg (Default: true)
 
Global Flags:
  [Misc]
    -V, --version,--ver,--versions            Show app versions information (Default: false)
    -h, --help,--info,--usage                 Show this help screen (-?) [Env: HELP] (Default: false)
 
Type '-h'/'-?' or '--help' to get command help screen.
More: '-D'/'--debug', '-V'/'--version', '-#'/'--build-info', '--no-color'...
 
 
Matched commands:
- 1. p | Cmd{'preset'}
- 2. c | Cmd{'preset.cmd'}
 
Matched flags:
- 1. p (+1) Flg{'preset.preset'} /short/ | [owner: Cmd{'preset'}]
- 2. v (+1) Flg{'.verbose'} /short/ | [owner: Cmd{''}]
 
ACTIONS:
 
$

The OnAction handler of preset cmd subcmd invoked the cmdr builtin defaultAction, which will print the debugging information.

In Matched commands section, the noteable things are all matched subcmds are listed here. And, the matched flags will be listed at Matched flags section. A fact shown, the flag p and v are both in the list even thought they are not inputted by end-user explicitly.

Command: Presetting Args

Injecting args to a command

Definitions

Run

额外的话题

Howto run a subcmd directly from root

Command

Command: Invokes

Command: Preset Args

Command: Redirect To

Command: Dynamic Cmd

Command: Dynamic Cmd From Config

Command: Event Handlers

On this page