func DefaultCmds() map[string]script.Cmd {
	cmds := script.DefaultCmds()
	cmds["skip"] = Skip()
	return cmds
}

// DefaultConds returns a set of broadly useful script conditions.
//
// This set includes all of the conditions in script.DefaultConds,
// as well as:
//
//   - Conditions of the form "exec:foo" are active when the executable "foo" is

package script

import (
	"cmd/go/internal/imports"
	"fmt"
	"os"
	"runtime"
	"sync"
)

// DefaultConds returns a set of broadly useful script conditions.
//
// Run the 'help' command within a script engine to view a list of the available
// conditions.
func DefaultConds() map[string]Cond {
	conds := make(map[string]Cond)

	conds["GOOS"] = PrefixCondition(
		"runtime.GOOS == <suffix>",

	"internal/platform"
	"internal/testenv"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"runtime/debug"
	"strings"
	"sync"
)

func scriptConditions() map[string]script.Cond {
	conds := scripttest.DefaultConds()

	add := func(name string, cond script.Cond) {
		if _, ok := conds[name]; ok {
			panic(fmt.Sprintf("condition %q is already registered", name))
		}
		conds[name] = cond
	}

)

// newScriptEngine returns a script engine augmented with commands for
// reproducing version-control repositories by replaying commits.
func newScriptEngine() *script.Engine {
	conds := script.DefaultConds()

	interrupt := func(cmd *exec.Cmd) error { return cmd.Process.Signal(os.Interrupt) }
	gracePeriod := 30 * time.Second // arbitrary

	cmds := script.DefaultCmds()
	cmds["at"] = scriptAt()

	Quiet bool
}

// NewEngine returns an Engine configured with a basic set of commands and conditions.
func NewEngine() *Engine {
	return &Engine{
		Cmds:  DefaultCmds(),
		Conds: DefaultConds(),
	}
}

// A Cmd is a command that is available to a script.
type Cmd interface {
	// Run begins running the command.
	//
	// If the command produces output or can be run in the background, run returns