class Shell(object):
def __init__(self, stdin=sys.stdin, stdout=sys.stdout, context: dict={}):
"""
Create a new shell.
:param stdin: file handle of the stdandard input
:param stdout: file handle of the standard output
:param context: exposed variables
"""
self.stdin = PipeIOStream(stdin.fileno())
self.stdout = PipeIOStream(stdout.fileno())
self.input_buffer = []
self.running = False
self.context = context
def start(self):
self.running = True
self.stdout.write(b"\r$>")
self.stdin.read_until(b'\n', self.on_line)
def on_line(self, chunk_bytes: bytes):
chunk = chunk_bytes.decode('utf-8', errors='ignore').rstrip('\n')
if not chunk.endswith('\\'):
self.input_buffer.append(chunk.strip())
line = " ".join(self.input_buffer)
self.input_buffer.clear()
self.on_command(line)
else:
self.input_buffer.append(chunk[:-1].strip())
self.stdout.write(b"\r ")
if self.running:
self.start()
@tornado.gen.engine
def on_command(self, command):
try:
if command:
code = compile(command + '\n', '<shell>', 'single')
res = eval(code, self.context)
if res is not None:
r = pprint.pformat(res).encode('utf-8')
yield tornado.gen.Task(self.stdout.write, r + b'\n')
except SystemExit:
raise
except:
yield tornado.gen.Task(self.stdout.write, traceback.format_exc().encode('utf-8'))
def test_pipe_iostream(self):
r, w = os.pipe()
rs = PipeIOStream(r, io_loop=self.io_loop)
ws = PipeIOStream(w, io_loop=self.io_loop)
ws.write(b"hel")
ws.write(b"lo world")
rs.read_until(b' ', callback=self.stop)
data = self.wait()
self.assertEqual(data, b"hello ")
rs.read_bytes(3, self.stop)
data = self.wait()
self.assertEqual(data, b"wor")
ws.close()
rs.read_until_close(self.stop)
data = self.wait()
self.assertEqual(data, b"ld")
rs.close()
def test_pipe_iostream(self):
r, w = os.pipe()
rs = PipeIOStream(r, io_loop=self.io_loop)
ws = PipeIOStream(w, io_loop=self.io_loop)
ws.write(b"hel")
ws.write(b"lo world")
rs.read_until(b" ", callback=self.stop)
data = self.wait()
self.assertEqual(data, b"hello ")
rs.read_bytes(3, self.stop)
data = self.wait()
self.assertEqual(data, b"wor")
ws.close()
rs.read_until_close(self.stop)
data = self.wait()
self.assertEqual(data, b"ld")
rs.close()
