modificar-a-blackhole.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
    Modifica todos los dominios que devuelven un email cuando no existe la cuenta de correo 
    y en su lugar deja de procesar ese correo.

    Haz backup del directorio antes de ejecutar este script!!!
    # cp -a /etc/valiases /etc/valiases-backup

"""

from tempfile import mkstemp
from shutil import move
import os

DIR = "/etc/valiases/"

def replace(file_path, pattern, subst):
    #Get owner and group
    stats = os.stat(file_path)
    #Create temp file
    fh, abs_path = mkstemp()
    with os.fdopen(fh,'w') as new_file:
        with open(file_path) as old_file:
            for line in old_file:
                if line.startswith("*:") and ":fail:" in line:
                    print(file_path)
                    new_file.write("*: :blackhole:\n")
                else:
                    new_file.write(line)

    #Remove original file
    os.remove(file_path)
    #Move new file
    move(abs_path, file_path)
    #Set permission, owner and group
    os.chown(file_path, stats.st_uid, stats.st_gid)
    os.chmod(file_path, 0o640)

for root, dirs, files in os.walk(DIR):
    for name in files:
        ruta = os.path.join(root, name)
        replace(ruta, "*: :fail:", "*: :blackhole:")