Added a rule to delete sudo for pacaur. (nvbn#787)

README.md

@@ -4,7 +4,7 @@ Magnificent app which corrects your previous console command,
 inspired by a [@liamosaur](https://twitter.com/liamosaur/)
 [tweet](https://twitter.com/liamosaur/status/506975850596536320).
 
-The Fuck is too slow? [Try experimental instant mode!](#experimental-instant-mode) 
+The Fuck is too slow? [Try experimental instant mode!](#experimental-instant-mode)
 
 [![gif with examples][examples-link]][examples-link]
 
@@ -278,6 +278,7 @@ using the matched rule and runs it. Rules enabled by default are as follows:
 * `tsuru_not_command` – fixes wrong `tsuru` commands like `tsuru shell`;
 * `tmux` – fixes `tmux` commands;
 * `unknown_command` – fixes hadoop hdfs-style "unknown command", for example adds missing '-' to the command on `hdfs dfs ls`;
+* `unsudo` – removes `sudo` from previous command if a process refuses to run on super user privilege.
 * `vagrant_up` – starts up the vagrant instance;
 * `whois` – fixes `whois` command;
 * `workon_doesnt_exists` – fixes `virtualenvwrapper` env name os suggests to create new.

tests/rules/test_unsudo.py

@@ -0,0 +1,22 @@
+import pytest
+from thefuck.rules.unsudo import match, get_new_command
+from thefuck.types import Command
+
+
+@pytest.mark.parametrize('output', [
+    'you cannot perform this operation as root'])
+def test_match(output):
+    assert match(Command('sudo ls', output))
+
+
+def test_not_match():
+    assert not match(Command('', ''))
+    assert not match(Command('sudo ls', 'Permission denied'))
+    assert not match(Command('ls', 'you cannot perform this operation as root'))
+
+
+@pytest.mark.parametrize('before, after', [
+    ('sudo ls', 'ls'),
+    ('sudo pacaur -S helloworld', 'pacaur -S helloworld')])
+def test_get_new_command(before, after):
+    assert get_new_command(Command(before, '')) == after

thefuck/rules/unsudo.py

@@ -0,0 +1,15 @@
+patterns = ['you cannot perform this operation as root']
+
+
+def match(command):
+    if command.script_parts and command.script_parts[0] != 'sudo':
+        return False
+
+    for pattern in patterns:
+        if pattern in command.output.lower():
+            return True
+    return False
+
+
+def get_new_command(command):
+    return ' '.join(command.script_parts[1:])