urfave-cli/command.go

package cli

import (
	"flag"
	"fmt"
	"sort"
	"strings"
)

// Command is a subcommand for a cli.App.
type Command struct {
	// The name of the command
	Name string
	// A list of aliases for the command
	Aliases []string
	// A short description of the usage of this command
	Usage string
	// Custom text to show on USAGE section of help
	UsageText string
	// A longer explanation of how the command works
	Description string
	// A short description of the arguments of this command
	ArgsUsage string
	// The category the command is part of
	Category string
	// The function to call when checking for bash command completions
	BashComplete BashCompleteFunc
	// An action to execute before any sub-subcommands are run, but after the context is ready
	// If a non-nil error is returned, no sub-subcommands are run
	Before BeforeFunc
	// An action to execute after any subcommands are run, but after the subcommand has finished
	// It is run even if Action() panics
	After AfterFunc
	// The function to call when this command is invoked
	Action ActionFunc
	// Execute this function if a usage error occurs.
	OnUsageError OnUsageErrorFunc
	// List of child commands
	Subcommands []*Command
	// List of flags to parse
	Flags []Flag
	// Treat all flags as normal arguments if true
	SkipFlagParsing bool
	// Boolean to hide built-in help command
	HideHelp bool
	// Boolean to hide this command from help or completion
	Hidden bool
	// Boolean to enable short-option handling so user can combine several
	// single-character bool arguments into one
	// i.e. foobar -o -v -> foobar -ov
	UseShortOptionHandling bool

	// Full name of command for help, defaults to full command name, including parent commands.
	HelpName        string
	commandNamePath []string

	// CustomHelpTemplate the text template for the command help topic.
	// cli.go uses text/template to render templates. You can
	// render custom help text by setting this variable.
	CustomHelpTemplate string
}

type CommandsByName []*Command

func (c CommandsByName) Len() int {
	return len(c)
}

func (c CommandsByName) Less(i, j int) bool {
	return lexicographicLess(c[i].Name, c[j].Name)
}

func (c CommandsByName) Swap(i, j int) {
	c[i], c[j] = c[j], c[i]
}

// FullName returns the full name of the command.
// For subcommands this ensures that parent commands are part of the command path
func (c *Command) FullName() string {
	if c.commandNamePath == nil {
		return c.Name
	}
	return strings.Join(c.commandNamePath, " ")
}

// Run invokes the command given the context, parses ctx.Args() to generate command-specific flags
func (c *Command) Run(ctx *Context) (err error) {
	if len(c.Subcommands) > 0 {
		return c.startApp(ctx)
	}

	if !c.HideHelp && HelpFlag != nil {
		// append help to flags
		c.appendFlag(HelpFlag)
	}

	if ctx.App.UseShortOptionHandling {
		c.UseShortOptionHandling = true
	}

	set, err := c.parseFlags(ctx.Args())

	context := NewContext(ctx.App, set, ctx)
	context.Command = c
	if checkCommandCompletions(context, c.Name) {
		return nil
	}

	if err != nil {
		if c.OnUsageError != nil {
			err = c.OnUsageError(context, err, false)
			context.App.handleExitCoder(context, err)
			return err
		}