feat(command): add commander

pkg/command/commander.go

@@ -0,0 +1,5 @@
+package command
+
+type Commander interface {
+	Run(name string, args ...string) (string, error)
+}

pkg/command/osexec.go

@@ -0,0 +1,39 @@
+package command
+
+import (
+	"bytes"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+)
+
+type OSExec struct {
+	out bytes.Buffer
+	err bytes.Buffer
+}
+
+func NewOSExec() *OSExec {
+	e := &OSExec{}
+	return e
+}
+
+func (e *OSExec) Run(name string, args ...string) (string, error) {
+	cmd := exec.Command(name, args...)
+	cmd.Stdout = &e.out
+	cmd.Stderr = &e.err
+
+	err := cmd.Run()
+	out := e.out.String()
+
+	{
+		if _, err := io.Copy(os.Stdout, &e.out); err != nil {
+			log.Print(err)
+		}
+		if _, err := io.Copy(os.Stderr, &e.err); err != nil {
+			log.Print(err)
+		}
+	}
+
+	return out, err
+}