pexec

Documentation

Overview

Package pexec provides a mechanism for invoking a program executable with a varying set of arguments.

Below is an example showing how you might invoke the `echo` executable with arguments;

package main

import (
	"os"

	"github.com/paketo-buildpacks/packit/pexec"
)

func main() {
	echo := pexec.NewExecutable("echo")

	err := echo.Execute(pexec.Execution{
		Args:   []string{"hello from pexec"},
		Stdout: os.Stdout,
	})
	if err != nil {
		panic(err)
	}

	// Output: hello from pexec
}

Index

• type Executable
  • func NewExecutable(name string) Executable
  • func (e Executable) Execute(execution Execution) error
• type Execution

Types

type Executable

type Executable struct {
	// contains filtered or unexported fields
}

Executable represents an executable on the $PATH.

func NewExecutable

func NewExecutable(name string) Executable

NewExecutable returns an instance of an Executable given the name of that executable. When given simply a name, the execuable will be looked up on the $PATH before execution. Alternatively, when given a path, the executable will use that path to invoke the executable file directly.

func (Executable) Execute

func (e Executable) Execute(execution Execution) error

Execute invokes the executable with a set of Execution arguments.

type Execution

type Execution struct {
	// Args is a list of the arguments to be passed to the executable.
	Args []string

	// Dir is the path to a directory from with the executable should be invoked.
	// If Dir is not set, the current working directory will be used.
	Dir string

	// Env is the set of environment variables that make up the environment for
	// the execution. If Env is not set, the existing os.Environ value will be
	// used.
	Env []string

	// Stdout is where the output of stdout will be written during the execution.
	Stdout io.Writer

	// Stderr is where the output of stderr will be written during the execution.
	Stderr io.Writer
}

Execution is the set of configurable options for a given execution of the executable.