lazygit/pkg/commands/os.go

package commands

import (
	"io/ioutil"
	"os"
	"os/exec"
	"regexp"
	"strings"

	"github.com/go-errors/errors"

	"github.com/jesseduffield/lazygit/pkg/config"
	"github.com/jesseduffield/lazygit/pkg/utils"
	"github.com/mgutz/str"
	"github.com/sirupsen/logrus"
	gitconfig "github.com/tcnksm/go-gitconfig"
)

// Platform stores the os state
type Platform struct {
	os                   string
	shell                string
	shellArg             string
	escapedQuote         string
	openCommand          string
	openLinkCommand      string
	fallbackEscapedQuote string
	skipEditorArg        string
}

// OSCommand holds all the os commands
type OSCommand struct {
	Log                *logrus.Entry
	Platform           *Platform
	Config             config.AppConfigurer
	command            func(string, ...string) *exec.Cmd
	getGlobalGitConfig func(string) (string, error)
	getenv             func(string) string
}

// NewOSCommand os command runner
func NewOSCommand(log *logrus.Entry, config config.AppConfigurer) *OSCommand {
	return &OSCommand{
		Log:                log,
		Platform:           getPlatform(),
		Config:             config,
		command:            exec.Command,
		getGlobalGitConfig: gitconfig.Global,
		getenv:             os.Getenv,
	}
}

// RunCommandWithOutput wrapper around commands returning their output and error
func (c *OSCommand) RunCommandWithOutput(command string) (string, error) {
	c.Log.WithField("command", command).Info("RunCommand")
	splitCmd := str.ToArgv(command)
	c.Log.Info(splitCmd)
	return sanitisedCommandOutput(
		c.command(splitCmd[0], splitCmd[1:]...).CombinedOutput(),
	)
}

// RunCommandWithOutputLive runs RunCommandWithOutputLiveWrapper
func (c *OSCommand) RunCommandWithOutputLive(command string, output func(string) string) error {
	return RunCommandWithOutputLiveWrapper(c, command, output)
}

// DetectUnamePass detect a username / password question in a command
// ask is a function that gets executen when this function detect you need to fillin a password
// The ask argument will be "username" or "password" and expects the user's password or username back
func (c *OSCommand) DetectUnamePass(command string, ask func(string) string) error {
	ttyText := ""
	errMessage := c.RunCommandWithOutputLive(command, func(word string) string {
		ttyText = ttyText + " " + word

		prompts := map[string]string{
			"password": `Password\s*for\s*'.+':`,
			"username": `Username\s*for\s*'.+':`,
		}

		for askFor, pattern := range prompts {
			if match, _ := regexp.MatchString(pattern, ttyText); match {
				ttyText = ""
				return ask(askFor)
			}
		}

		return ""
	})
	return errMessage
}

// RunCommand runs a command and just returns the error
func (c *OSCommand) RunCommand(command string) error {
	_, err := c.RunCommandWithOutput(command)
	return err
}

// FileType tells us if the file is a file, directory or other
func (c *OSCommand) FileType(path string) string {
	fileInfo, err := os.Stat(path)
	if err != nil {
		return "other"
	}
	if fileInfo.IsDir() {
		return "directory"
	}
	return "file"
}

// RunDirectCommand wrapper around direct commands
func (c *OSCommand) RunDirectCommand(command string) (string, error) {
	c.Log.WithField("command", command).Info("RunDirectCommand")

	return sanitisedCommandOutput(
		c.command(c.Platform.shell, c.Platform.shellArg, command).
			CombinedOutput(),
	)
}

func sanitisedCommandOutput(output []byte, err error) (string, error) {
	outputString := string(output)
	if err != nil {
		// errors like 'exit status 1' are not very useful so we'll create an error
		// from the combined output
		if outputString == "" {
			return "", errors.Wrap(err, 0)
		}
		return outputString, errors.New(outputString)
	}
	return outputString, nil
}

// OpenFile opens a file with the given
func (c *OSCommand) OpenFile(filename string) error {
	commandTemplate := c.Config.GetUserConfig().GetString("os.openCommand")
	templateValues := map[string]string{
		"filename": c.Quote(filename),
	}

	command := utils.ResolvePlaceholderString(commandTemplate, templateValues)
	err := c.RunCommand(command)
	return err
}

// OpenLink opens a file with the given
func (c *OSCommand) OpenLink(link string) error {
	commandTemplate := c.Config.GetUserConfig().GetString("os.openLinkCommand")
	templateValues := map[string]string{
		"link": c.Quote(link),
	}

	command := utils.ResolvePlaceholderString(commandTemplate, templateValues)
	err := c.RunCommand(command)
	return err
}

// EditFile opens a file in a subprocess using whatever editor is available,
// falling back to core.editor, VISUAL, EDITOR, then vi
func (c *OSCommand) EditFile(filename string) (*exec.Cmd, error) {
	editor, _ := c.getGlobalGitConfig("core.editor")

	if editor == "" {
		editor = c.getenv("VISUAL")
	}
	if editor == "" {
		editor = c.getenv("EDITOR")
	}
	if editor == "" {
		if err := c.RunCommand("which vi"); err == nil {
			editor = "vi"
		}
	}
	if editor == "" {
		return nil, errors.New("No editor defined in $VISUAL, $EDITOR, or git config")
	}

	return c.PrepareSubProcess(editor, filename), nil
}

// PrepareSubProcess iniPrepareSubProcessrocess then tells the Gui to switch to it
func (c *OSCommand) PrepareSubProcess(cmdName string, commandArgs ...string) *exec.Cmd {
	return c.command(cmdName, commandArgs...)
}

// Quote wraps a message in platform-specific quotation marks
func (c *OSCommand) Quote(message string) string {
	message = strings.Replace(message, "`", "\\`", -1)
	escapedQuote := c.Platform.escapedQuote
	if strings.Contains(message, c.Platform.escapedQuote) {
		escapedQuote = c.Platform.fallbackEscapedQuote
	}
	return escapedQuote + message + escapedQuote
}

// Unquote removes wrapping quotations marks if they are present
// this is needed for removing quotes from staged filenames with spaces
func (c *OSCommand) Unquote(message string) string {
	return strings.Replace(message, `"`, "", -1)
}

// AppendLineToFile adds a new line in file
func (c *OSCommand) AppendLineToFile(filename, line string) error {
	f, err := os.OpenFile(filename, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
	if err != nil {
		return errors.Wrap(err, 0)
	}
	defer f.Close()

	_, err = f.WriteString("\n" + line)
	if err != nil {
		errors.Wrap(err, 0)
	}
	return nil
}

// CreateTempFile writes a string to a new temp file and returns the file's name
func (c *OSCommand) CreateTempFile(filename, content string) (string, error) {
	tmpfile, err := ioutil.TempFile("", filename)
	if err != nil {
		c.Log.Error(err)
		return "", errors.Wrap(err, 0)
	}

	if _, err := tmpfile.WriteString(content); err != nil {
		c.Log.Error(err)
		return "", errors.Wrap(err, 0)
	}
	if err := tmpfile.Close(); err != nil {
		c.Log.Error(err)
		return "", errors.Wrap(err, 0)
	}

	return tmpfile.Name(), nil
}

// RemoveFile removes a file at the specified path
func (c *OSCommand) RemoveFile(filename string) error {
	err := os.Remove(filename)
	return errors.Wrap(err, 0)
}

// FileExists checks whether a file exists at the specified path
func (c *OSCommand) FileExists(path string) (bool, error) {
	if _, err := os.Stat(path); err != nil {
		if os.IsNotExist(err) {
			return false, nil
		}
		return false, err
	}
	return true, nil
}

// RunPreparedCommand takes a pointer to an exec.Cmd and runs it
// this is useful if you need to give your command some environment variables
// before running it
func (c *OSCommand) RunPreparedCommand(cmd *exec.Cmd) error {
	out, err := cmd.CombinedOutput()
	outString := string(out)
	c.Log.Info(outString)
	if err != nil {
		if len(outString) == 0 {
			return err
		}
		return errors.New(outString)
	}
	return nil
}