lazygit/pkg/commands/exec_live_default.go

// +build !windows

package commands

import (
	"bufio"
	"os"
	"os/exec"
	"regexp"
	"strings"
	"sync"

	"github.com/kr/pty"
)

// RunCommandWithOutputLiveWrapper runs a command and return every word that gets written in stdout
// Output is a function that executes by every word that gets read by bufio
// As return of output you need to give a string that will be written to stdin
// NOTE: If the return data is empty it won't written anything to stdin
// NOTE: You don't have to include a enter in the return data this function will do that for you
func RunCommandWithOutputLiveWrapper(c *OSCommand, command string, output func(string) string) (errorMessage string, codeError error) {
	cmdOutput := []string{}

	splitCmd := ToArgv(command)
	cmd := exec.Command(splitCmd[0], splitCmd[1:]...)

	cmd.Env = os.Environ()
	cmd.Env = append(cmd.Env, "LANG=en_US.utf8", "LC_ALL=en_US.UTF-8")

	tty, err := pty.Start(cmd)

	if err != nil {
		return errorMessage, err
	}

	var waitForBufio sync.WaitGroup
	waitForBufio.Add(1)

	defer func() {
		_ = tty.Close()
	}()

	go func() {
		// Regex to cleanup the command output
		// sometimes the output words include unneeded spaces at eatch end of the string
		re := regexp.MustCompile(`(^\s*)|(\s*$)`)

		scanner := bufio.NewScanner(tty)
		scanner.Split(bufio.ScanWords)
		for scanner.Scan() {
			toOutput := re.ReplaceAllString(scanner.Text(), "")
			cmdOutput = append(cmdOutput, toOutput)
			toWrite := output(toOutput)
			if len(toWrite) > 0 {
				_, _ = tty.Write([]byte(toWrite + "\n"))
			}
		}
		waitForBufio.Done()
	}()

	if err := cmd.Wait(); err != nil {
		waitForBufio.Wait()
		return strings.Join(cmdOutput, " "), err
	}

	return errorMessage, nil
}