#N/A: Add port_already_in_use rule

README.md

@@ -210,6 +210,7 @@ using the matched rule and runs it. Rules enabled by default are as follows:
 * `no_such_file` – creates missing directories with `mv` and `cp` commands;
 * `open` – either prepends `http://` to address passed to `open` or create a new file or directory and passes it to `open`;
 * `pip_unknown_command` – fixes wrong `pip` commands, for example `pip instatl/pip install`;
+* `port_already_in_use` – kills process that bound port;
 * `python_command` – prepends `python` when you trying to run not executable/without `./` python script;
 * `python_execute` – appends missing `.py` when executing Python files;
 * `quotation_marks` – fixes uneven usage of `'` and `"` when containing args';

tests/rules/test_port_already_in_use.py

@@ -0,0 +1,101 @@
+from io import BytesIO
+
+import pytest
+from thefuck.rules.port_already_in_use import match, get_new_command
+from tests.utils import Command
+
+outputs = [
+    '''
+
+DE 70% 1/1 build modulesevents.js:141
+      throw er; // Unhandled 'error' event
+      ^
+
+Error: listen EADDRINUSE 127.0.0.1:8080
+    at Object.exports._errnoException (util.js:873:11)
+    at exports._exceptionWithHostPort (util.js:896:20)
+    at Server._listen2 (net.js:1250:14)
+    at listen (net.js:1286:10)
+    at net.js:1395:9
+    at GetAddrInfoReqWrap.asyncCallback [as callback] (dns.js:64:16)
+    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:83:10)
+
+    ''',
+    '''
+[6:40:01 AM] <START> Building Dependency Graph
+[6:40:01 AM] <START> Crawling File System
+ ERROR  Packager can't listen on port 8080
+Most likely another process is already using this port
+Run the following command to find out which process:
+
+   lsof -n -i4TCP:8080
+
+You can either shut down the other process:
+
+   kill -9 <PID>
+
+or run packager on different port.
+
+    ''',
+    '''
+Traceback (most recent call last):
+  File "/usr/lib/python3.5/runpy.py", line 184, in _run_module_as_main
+    "__main__", mod_spec)
+  File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
+    exec(code, run_globals)
+  File "/home/nvbn/exp/code_view/server/code_view/main.py", line 14, in <module>
+    web.run_app(app)
+  File "/home/nvbn/.virtualenvs/code_view/lib/python3.5/site-packages/aiohttp/web.py", line 310, in run_app
+    backlog=backlog))
+  File "/usr/lib/python3.5/asyncio/base_events.py", line 373, in run_until_complete
+    return future.result()
+  File "/usr/lib/python3.5/asyncio/futures.py", line 274, in result
+    raise self._exception
+  File "/usr/lib/python3.5/asyncio/tasks.py", line 240, in _step
+    result = coro.send(None)
+  File "/usr/lib/python3.5/asyncio/base_events.py", line 953, in create_server
+    % (sa, err.strerror.lower()))
+OSError: [Errno 98] error while attempting to bind on address ('0.0.0.0', 8080): address already in use
+Task was destroyed but it is pending!
+task: <Task pending coro=<RedisProtocol._reader_coroutine() running at /home/nvbn/.virtualenvs/code_view/lib/python3.5/site-packages/asyncio_redis/protocol.py:921> wait_for=<Future pending cb=[Task._wakeup()]>>
+    '''
+]
+
+lsof_stdout = b'''COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
+node    18233 nvbn   16u  IPv4 557134      0t0  TCP localhost:http-alt (LISTEN)
+'''
+
+
+@pytest.fixture(autouse=True)
+def lsof(mocker):
+    patch = mocker.patch('thefuck.rules.port_already_in_use.Popen')
+    patch.return_value.stdout = BytesIO(lsof_stdout)
+    return patch
+
+
+@pytest.mark.usefixtures('no_memoize')
+@pytest.mark.parametrize(
+    'command',
+    [Command('./app', stdout=output) for output in outputs]
+    + [Command('./app', stderr=output) for output in outputs])
+def test_match(command):
+    assert match(command)
+
+
+@pytest.mark.usefixtures('no_memoize')
+@pytest.mark.parametrize('command, lsof_output', [
+    (Command('./app'), lsof_stdout),
+    (Command('./app', stdout=outputs[1]), b''),
+    (Command('./app', stderr=outputs[2]), b'')])
+def test_not_match(lsof, command, lsof_output):
+    lsof.return_value.stdout = BytesIO(lsof_output)
+
+    assert not match(command)
+
+
+@pytest.mark.parametrize(
+    'command',
+    [Command('./app', stdout=output) for output in outputs]
+    + [Command('./app', stderr=output) for output in outputs])
+def test_get_new_command(command):
+    assert get_new_command(command) == 'kill 18233 && ./app'

thefuck/rules/port_already_in_use.py

@@ -0,0 +1,39 @@
+import re
+from subprocess import Popen, PIPE
+from thefuck.utils import memoize
+from thefuck.shells import shell
+
+patterns = [r"bind on address \('.*', (?P<port>\d+)\)",
+            r'Unable to bind [^ ]*:(?P<port>\d+)',
+            r"can't listen on port (?P<port>\d+)",
+            r'listen EADDRINUSE [^ ]*:(?P<port>\d+)']
+
+
+@memoize
+def _get_pid_by_port(port):
+    proc = Popen(['lsof', '-i', ':{}'.format(port)], stdout=PIPE)
+    lines = proc.stdout.read().decode().split('\n')
+    if len(lines) > 1:
+        return lines[1].split()[1]
+    else:
+        return None
+
+
+@memoize
+def _get_used_port(command):
+    for pattern in patterns:
+        matched = (re.search(pattern, command.stderr)
+                   or re.search(pattern, command.stdout))
+        if matched:
+            return matched.group('port')
+
+
+def match(command):
+    port = _get_used_port(command)
+    return port and _get_pid_by_port(port)
+
+
+def get_new_command(command):
+    port = _get_used_port(command)
+    pid = _get_pid_by_port(port)
+    return shell.and_(u'kill {}'.format(pid), command.script)