context.go

package script

import (
	"io"
	"os"

	isatty "github.com/mattn/go-isatty"
	"github.com/spf13/afero"
)

// Context for script operations. A Context includes the working directory and provides
// access the buffers and results of commands run in the Context.
// Using different Contexts it is possible to handle multiple separate environments.
type Context struct {
	workingDir string
	env        map[string]string
	fs         afero.Fs
	stdout     io.Writer
	stderr     io.Writer
	stdin      io.Reader
	isTTY      bool
}

// NewContext returns a pointer to a new Context.
func NewContext() (context *Context) {
	// initialize Context
	context = &Context{
		env:    make(map[string]string, 0),
		fs:     afero.NewOsFs(),
		stdout: os.Stdout,
		stderr: os.Stderr,
		stdin:  os.Stdin,
	}

	cwd, err := os.Getwd()
	if err == nil {
		context.SetWorkingDir(cwd)
	}
	return
}

// SetWorkingDir changes the current working dir
func (c *Context) SetWorkingDir(workingDir string) {
	c.workingDir = workingDir
}

// WorkingDir retrieves the current working dir
func (c *Context) WorkingDir() string {
	return c.workingDir
}

// SetWorkingDirTemp changes the current working dir to a temporary directory, returning an error in case something went wrong
func (c *Context) SetWorkingDirTemp() error {
	dir, err := c.TempDir()
	if err != nil {
		return err
	}
	c.SetWorkingDir(dir)
	return nil
}

// IsUserRoot checks if a user is root priviledged (Linux and Mac only? Windows?)
func (c *Context) IsUserRoot() bool {
	return os.Geteuid() == 0
}

// IsTerminal returns if this program is run inside an interactive terminal
func (c Context) IsTerminal() bool {
	return !(os.Getenv("TERM") == "dumb" || (!isatty.IsTerminal(os.Stdout.Fd()) && !isatty.IsCygwinTerminal(os.Stdout.Fd())))
}