1 files changed, 104 insertions, 0 deletions
diff --git a/internal/io/run/run.go b/internal/io/run/run.go
new file mode 100644
index 0000000..b608639
--- /dev/null
+++ b/internal/io/run/run.go
@@ -0,0 +1,104 @@
+package run
+
+import (
+	"bufio"
+	"context"
+	"io"
+	"os/exec"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/mimecast/dtail/internal/io/line"
+	"github.com/mimecast/dtail/internal/io/logger"
+)
+
+// Run is for execute a command.
+type Run struct {
+	commandPath string
+	args        []string
+	cmd         *exec.Cmd
+}
+
+// New returns a new command runner.
+func New(commandPath string, args []string) Run {
+	return Run{
+		commandPath: commandPath,
+		args:        args,
+	}
+}
+
+// Start running the command.
+func (r Run) Start(ctx context.Context, lines chan<- line.Line) (pid int, ec int, err error) {
+	done := make(chan struct{})
+	defer close(done)
+
+	ec = -1
+	pid = -1
+
+	if len(r.args) > 0 {
+		logger.Debug(r.commandPath, strings.Join(r.args, " "))
+		r.cmd = exec.CommandContext(ctx, r.commandPath, strings.Join(r.args, " "))
+	} else {
+		logger.Debug(r.commandPath)
+		r.cmd = exec.CommandContext(ctx, r.commandPath)
+	}
+
+	stdoutPipe, myErr := r.cmd.StdoutPipe()
+	if err != nil {
+		err = myErr
+		return
+	}
+
+	stderrPipe, myErr := r.cmd.StderrPipe()
+	if myErr != nil {
+		err = myErr
+		return
+	}
+
+	if myErr := r.cmd.Start(); err != nil {
+		err = myErr
+		return
+	}
+
+	pid = r.cmd.Process.Pid
+	ec = 0
+
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	go r.pipeToLines(done, &wg, pid, stdoutPipe, "STDOUT", lines)
+	go r.pipeToLines(done, &wg, pid, stderrPipe, "STDERR", lines)
+
+	if err = r.cmd.Wait(); err != nil {
+		if exitError, ok := err.(*exec.ExitError); ok {
+			ec = exitError.ExitCode()
+		}
+	}
+
+	return
+}
+
+func (r Run) pipeToLines(done chan struct{}, wg *sync.WaitGroup, pid int, reader io.Reader, what string, lines chan<- line.Line) {
+	defer wg.Done()
+	bufReader := bufio.NewReader(reader)
+
+	for {
+		lineStr, err := bufReader.ReadString('\n')
+		for err == nil {
+			lines <- line.Line{
+				Content:         []byte(lineStr),
+				Count:           uint64(pid),
+				TransmittedPerc: 100,
+				SourceID:        what,
+			}
+			lineStr, err = bufReader.ReadString('\n')
+		}
+		select {
+		case <-done:
+			return
+		default:
+		}
+		time.Sleep(time.Millisecond * 10)
+	}
+}