Add remaining (sans spawn, testbench)

exec/exec.go

@@ -0,0 +1,26 @@
+package exec
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"syscall"
+)
+
+func Exec() {
+	defer fmt.Println("defer println")
+	lsPath, err := exec.LookPath("ls")
+	if err != nil {
+		panic(err)
+	}
+
+	envs := os.Environ()
+
+	// Exec replaces currently running go program and doesn't seem to care for `defer`s either
+	execErr := syscall.Exec(lsPath, []string{"-l", "-a", "-h", "/"}, envs)
+	if execErr != nil {
+		panic(execErr)
+	}
+
+	fmt.Println("Stopping the program")
+}