#682: Warn if PS1 changed after thefuck initialization

thefuck/output_readers/read_log.py

@@ -69,6 +69,11 @@ def get_output(script):
         warn("Output log isn't specified")
         return None, None
 
+    if const.USER_COMMAND_MARK not in os.environ.get('PS1', ''):
+        warn("PS1 doesn't contain user command mark, please ensure "
+             "that PS1 is not changed after The Fuck alias initialization")
+        return None, None
+
     try:
         with open(os.environ['THEFUCK_OUTPUT_LOG'], 'rb') as log_file:
             lines = _get_output_lines(script, log_file)