diff --git a/exec.py b/exec.py
new file mode 100644
index 0000000..6fc1e31
--- /dev/null
+++ b/exec.py
@@ -0,0 +1,75 @@
+"""
+Execute shell command
+For example, list directory contents:
+def ls(folder):
+    cmd = Shell(['/bin/sh', '-c', 'ls -la ' + folder], None)
+    cmd.exec()
+    for chunk in cmd.output:
+        print(chunk.strip().decode())
+"""
+import frida
+from frida.application import Reactor
+import threading
+import click
+
+
+class Shell(object):
+    def __init__(self, argv, env):
+        self._stop_requested = threading.Event()
+        self._reactor = Reactor(run_until_return=lambda reactor: self._stop_requested.wait())
+
+        self._device = frida.get_usb_device()
+        self._sessions = set()
+
+        self._device.on("child-added", lambda child: self._reactor.schedule(lambda: self._on_child_added(child)))
+        self._device.on("child-removed", lambda child: self._reactor.schedule(lambda: self._on_child_removed(child)))
+        self._device.on("output", lambda pid, fd, data: self._reactor.schedule(lambda: self._on_output(pid, fd, data)))
+
+        self.argv = argv
+        self.env = env
+        self.output = []  # stdout will pushed into array
+
+    def exec(self):
+        self._reactor.schedule(lambda: self._start())
+        self._reactor.run()
+
+    def _start(self):
+        click.secho("✔ spawn(argv={})".format(self.argv), fg='green', dim=True)
+        pid = self._device.spawn(self.argv, env=self.env, stdio='pipe')
+        self._instrument(pid)
+
+    def _stop_if_idle(self):
+        if len(self._sessions) == 0:
+            self._stop_requested.set()
+
+    def _instrument(self, pid):
+        click.secho("✔ attach(pid={})".format(pid), fg='green', dim=True)
+        session = self._device.attach(pid)
+        session.on("detached", lambda reason: self._reactor.schedule(lambda: self._on_detached(pid, session, reason)))
+        click.secho("✔ enable_child_gating()", fg='green', dim=True)
+        session.enable_child_gating()
+        # print("✔ resume(pid={})".format(pid))
+        self._device.resume(pid)
+        self._sessions.add(session)
+
+    def _on_child_added(self, child):
+        click.secho("⚡ child_added: {}".format(child), fg='green', dim=True)
+        self._instrument(child.pid)
+
+    @staticmethod
+    def _on_child_removed(child):
+        click.secho("⚡ child_removed: {}".format(child), fg='green', dim=True)
+
+    def _on_output(self, pid, fd, data):
+        # if len(data) > 0:
+            # print("⚡ output: pid={}, fd={}, data={}".format(pid, fd, repr(data)))
+        self.output.append(data)
+
+    def _on_detached(self, pid, session, reason):
+        click.secho("⚡ detached: pid={}, reason='{}'".format(pid, reason), fg='green', dim=True)
+        self._sessions.remove(session)
+        self._reactor.schedule(self._stop_if_idle, delay=0.5)
+
+    @staticmethod
+    def _on_message(pid, message):
+        click.secho("⚡ message: pid={}, payload={}".format(pid, message), fg='green', dim=True)