From ca3f8d0b43d9826636115b44ffb40247a1a34c3a Mon Sep 17 00:00:00 2001
From: Julien Duponchelle <julien@gns3.net>
Date: Fri, 2 Jun 2017 14:50:34 +0200
Subject: [PATCH] Provide easy to test a shell by using stdin as an input

---
 gns3server/utils/asyncio/embed_shell.py | 71 +++++++++++++++----------
 1 file changed, 42 insertions(+), 29 deletions(-)

diff --git a/gns3server/utils/asyncio/embed_shell.py b/gns3server/utils/asyncio/embed_shell.py
index ccd3520c..fac81d3f 100644
--- a/gns3server/utils/asyncio/embed_shell.py
+++ b/gns3server/utils/asyncio/embed_shell.py
@@ -136,6 +136,39 @@ def create_telnet_shell(shell, loop=None):
     return AsyncioTelnetServer(reader=shell.writer, writer=shell.reader, binary=False, echo=False)
 
 
+def create_stdin_shell(shell, loop=None):
+    """
+    Run a shell application with a stdin frontend
+
+    :param application: An EmbedShell instance
+    :param loop: The event loop
+    :returns: Telnet server
+    """
+    @asyncio.coroutine
+    def feed_stdin(loop, reader):
+        while True:
+            line = yield from loop.run_in_executor(None, sys.stdin.readline)
+            reader.feed_data(line.encode())
+
+    @asyncio.coroutine
+    def read_stdout(writer):
+        while True:
+            c = yield from writer.read(1)
+            print(c.decode(), end='')
+            sys.stdout.flush()
+
+    reader = asyncio.StreamReader()
+    writer = asyncio.StreamReader()
+    shell.reader = reader
+    shell.writer = writer
+    if loop is None:
+        loop = asyncio.get_event_loop()
+
+    reader_task = loop.create_task(feed_stdin(loop, reader))
+    writer_task = loop.create_task(read_stdout(writer))
+    shell_task = loop.create_task(shell.run())
+    return asyncio.gather(shell_task, writer_task, reader_task)
+
 if __name__ == '__main__':
     loop = asyncio.get_event_loop()
 
@@ -154,34 +187,14 @@ if __name__ == '__main__':
                 return 'world\n'
 
     # Demo using telnet
-    server = create_telnet_shell(Demo())
-    coro = asyncio.start_server(server.run, '127.0.0.1', 4444, loop=loop)
-    s = loop.run_until_complete(coro)
-    try:
-        loop.run_forever()
-    except KeyboardInterrupt:
-        pass
+    # server = create_telnet_shell(Demo())
+    # coro = asyncio.start_server(server.run, '127.0.0.1', 4444, loop=loop)
+    # s = loop.run_until_complete(coro)
+    # try:
+    #     loop.run_forever()
+    # except KeyboardInterrupt:
+    #     pass
 
     # Demo using stdin
-    # @asyncio.coroutine
-    # def feed_stdin(loop, reader):
-    #     while True:
-    #         line = yield from loop.run_in_executor(None, sys.stdin.readline)
-    #         reader.feed_data(line.encode())
-    #
-    # @asyncio.coroutine
-    # def read_stdout(writer):
-    #     while True:
-    #         c = yield from writer.read(1)
-    #         print(c.decode(), end='')
-    #         sys.stdout.flush()
-    #
-    # reader = asyncio.StreamReader()
-    # writer = asyncio.StreamReader()
-    # shell = Demo(reader, writer, loop=loop)
-    #
-    # reader_task = loop.create_task(feed_stdin(loop, reader))
-    # writer_task = loop.create_task(read_stdout(writer))
-    # shell_task = loop.create_task(shell.run())
-    # loop.run_until_complete(asyncio.gather(shell_task, writer_task, reader_task))
-    # loop.close()
+    loop.run_until_complete(create_stdin_shell(Demo()))
+    loop.close()