lazygit/pkg/gui/pty.go

// +build !windows

package gui

import (
	"os/exec"

	"github.com/creack/pty"
)

func (gui *Gui) onResize() error {
	if gui.State.Ptmx == nil {
		return nil
	}
	mainView := gui.getMainView()
	width, height := mainView.Size()

	if err := pty.Setsize(gui.State.Ptmx, &pty.Winsize{Cols: uint16(width), Rows: uint16(height)}); err != nil {
		return err
	}

	// TODO: handle resizing properly

	return nil
}

// Some commands need to output for a terminal to active certain behaviour.
// For example,  git won't invoke the GIT_PAGER env var unless it thinks it's
// talking to a terminal. We typically write cmd outputs straight to a view,
// which is just an io.Reader. the pty package lets us wrap a command in a
// pseudo-terminal meaning we'll get the behaviour we want from the underlying
// command.
func (gui *Gui) newPtyTask(viewName string, cmd *exec.Cmd) error {
	width, _ := gui.getMainView().Size()
	pager := gui.GitCommand.GetPager(width)

	if pager == "" {
		// if we're not using a custom pager we don't need to use a pty
		return gui.newCmdTask(viewName, cmd)
	}

	cmd.Env = append(cmd.Env, "GIT_PAGER="+pager)

	view, err := gui.g.View(viewName)
	if err != nil {
		return nil // swallowing for now
	}

	_, height := view.Size()
	_, oy := view.Origin()

	manager := gui.getManager(view)

	ptmx, err := pty.Start(cmd)
	if err != nil {
		return err
	}

	gui.State.Ptmx = ptmx
	onClose := func() {
		ptmx.Close()
		gui.State.Ptmx = nil
	}

	if err := gui.onResize(); err != nil {
		return err
	}

	if err := manager.NewTask(manager.NewCmdTask(ptmx, cmd, height+oy+10, onClose)); err != nil {
		return err
	}

	return nil
}