add ability for live output, add events system

linux/events.go

@@ -0,0 +1,10 @@
+package linux
+
+const (
+	EventOutput = iota
+	EventStderr
+)
+
+type EventOutputData struct {
+	Output string
+}

linux/interface.go

@@ -2,10 +2,17 @@ package linux
 
 import (
 	"errors"
+	"io"
+	"sync"
 )
 
 type LinuxCommand struct {
 	Options  CommandOptions
+	handlers map[int]interface{}
+	wg       sync.WaitGroup
+	stdout   io.ReadCloser
+	stderr   io.ReadCloser
+	stdin    io.WriteCloser
 }
 
 type CommandOptions struct {
@@ -24,4 +31,5 @@ var (
 	ErrRunningCmd           = errors.New("error running command")
 	ErrCommandNotFound      = errors.New("error command not found")
 	ErrCommandNotExecutable = errors.New("error command not executable")
+	ErrInvalidHandler       = errors.New("invalid handler")
 )

linux/run.go

@@ -1,10 +1,15 @@
 package linux
 
 import (
+	"bufio"
 	"errors"
 	"fmt"
+	"golang.org/x/sys/unix"
 	"os"
 	"os/exec"
+	"os/signal"
+	"strings"
+	"syscall"
 )
 
 func NewCommand(options CommandOptions) (*LinuxCommand, error) {
@@ -23,33 +28,67 @@ func NewCommand(options CommandOptions) (*LinuxCommand, error) {
 
 	return &LinuxCommand{
 		Options:  options,
+		handlers: make(map[int]interface{}),
 	}, nil
 
 }
 
+func (cmd *LinuxCommand) AddHandler(handler interface{}) error {
+
+	switch h := handler.(type) {
+	case func(data EventOutputData) error:
+		cmd.handlers[EventOutput] = h
+		break
+	default:
+		return ErrInvalidHandler
+	}
+
+	return nil
+
+}
+
 func (cmd *LinuxCommand) Run() error {
 
-	var sourceCommand string
+	var sourceCommand strings.Builder
 	for _, value := range cmd.Options.Sources {
-		sourceCommand += fmt.Sprintf("source %s && ", value)
+		sourceCommand.WriteString(fmt.Sprintf("source %s && ", value))
 	}
 
-	command := exec.Command(cmd.Options.Shell, "-c", sourceCommand+cmd.Options.Command)
+	var commandOptions strings.Builder
+	commandOptions.WriteString(" ")
+	for index, arg := range cmd.Options.Args {
+		if len(cmd.Options.Args)-1 == index {
+			commandOptions.WriteString(fmt.Sprintf("%s", arg))
+		} else {
+			commandOptions.WriteString(fmt.Sprintf("%s ", arg))
+		}
+	}
+
+	command := exec.Command(cmd.Options.Shell, "-c", sourceCommand.String()+cmd.Options.Command+commandOptions.String())
 	command.Dir = cmd.Options.Cwd
-	command.Args = append(command.Args, cmd.Options.Args...)
 
-	// Loop through env to format and add them to the command.
+	var signalChannel chan os.Signal
-	for key, value := range cmd.Options.Env {
-		command.Env = append(command.Env, fmt.Sprintf("%s=%s", key, value))
-	}
 
-	isCommandExecutable, err := cmd.isCommandExecutable(cmd.Options.Command)
+	if len(cmd.handlers) != 0 {
+		command.SysProcAttr = &unix.SysProcAttr{Setsid: true}
+		signalChannel = make(chan os.Signal, 1)
+		signal.Notify(signalChannel, unix.SIGINT, unix.SIGTERM)
+
+		var err error
+		cmd.stdout, err = command.StdoutPipe()
 		if err != nil {
 			return err
 		}
 
-	if !isCommandExecutable {
+		cmd.stdin, err = command.StdinPipe()
-		return ErrCommandNotExecutable
+		if err != nil {
+			return err
+		}
+
+		cmd.stderr, err = command.StderrPipe()
+		if err != nil {
+			return err
+		}
 	}
 
 	if err := command.Start(); err != nil {
@@ -65,6 +104,67 @@ func (cmd *LinuxCommand) Run() error {
 		}
 	}
 
+	cmd.wg.Add(3)
+
+	go func() {
+		defer cmd.wg.Done()
+		scanner := bufio.NewScanner(cmd.stderr)
+		for scanner.Scan() {
+			line := scanner.Text()
+			if h, ok := cmd.handlers[EventOutput]; ok {
+				if err := h.(func(data EventOutputData) error)(EventOutputData{
+					Output: line,
+				}); err != nil {
+					return
+				}
+			}
+		}
+	}()
+
+	go func() {
+		defer cmd.wg.Done()
+
+		scanner := bufio.NewScanner(cmd.stdout)
+		for scanner.Scan() {
+			line := scanner.Text()
+			if h, ok := cmd.handlers[EventOutput]; ok {
+				if err := h.(func(data EventOutputData) error)(EventOutputData{
+					Output: line,
+				}); err != nil {
+					return
+				}
+			}
+		}
+	}()
+
+	go func() {
+		defer cmd.wg.Done()
+
+		select {
+		case _, ok := <-signalChannel:
+			if !ok {
+				return
+			}
+			if err := unix.Kill(-command.Process.Pid, syscall.SIGINT); err != nil {
+				return
+			}
+		}
+	}()
+
+	// Loop through env to format and add them to the command.
+	for key, value := range cmd.Options.Env {
+		command.Env = append(command.Env, fmt.Sprintf("%s=%s", key, value))
+	}
+
+	isCommandExecutable, err := cmd.isCommandExecutable(cmd.Options.Command)
+	if err != nil {
+		return err
+	}
+
+	if !isCommandExecutable {
+		return ErrCommandNotExecutable
+	}
+
 	if err := command.Wait(); err != nil {
 		var exitErr *exec.ExitError
 		if errors.As(err, &exitErr) {
@@ -78,6 +178,10 @@ func (cmd *LinuxCommand) Run() error {
 		}
 	}
 
+	close(signalChannel)
+	signal.Stop(signalChannel)
+	cmd.wg.Wait()
+
 	return nil
 
 }