Host File Website Blocker
This utility blocks access to specific websites by modifying the operating system's hosts file. It redirects the target domains to 127.0.0.1 (localhost), causing the browser to fail when trying to connect.
Modules Used:
os: To determine the operating system and file paths.- argparse: To handle command-line arguments.
ctypes: (Windows only) To check for administrative privileges.
The Code
Save this as blocker.py.
import os
import sys
import argparse
# Determine hosts file path based on OS
if os.name == 'nt':
HOSTS_PATH = r"C:\Windows\System32\drivers\etc\hosts"
else:
HOSTS_PATH = "/etc/hosts"
REDIRECT_IP = "127.0.0.1"
def is_admin():
"""Checks if the script has admin/root privileges."""
try:
if os.name == 'nt':
import ctypes
return ctypes.windll.shell32.IsUserAnAdmin() != 0
else:
return os.getuid() == 0
except:
return False
def block_sites(websites):
if not is_admin():
print("Error: This script requires Administrator/Root privileges to modify the hosts file.")
return
print(f"Blocking: {', '.join(websites)}")
try:
with open(HOSTS_PATH, 'r+') as file:
content = file.read()
for site in websites:
if site in content:
print(f" Skipping {site} (already blocked)")
else:
# Block domain and www.domain
file.write(f"{REDIRECT_IP} {site}\n")
file.write(f"{REDIRECT_IP} www.{site}\n")
print(f" Blocked {site}")
except PermissionError:
print("Permission denied. Please run as Administrator/Root.")
def unblock_sites(websites):
if not is_admin():
print("Error: This script requires Administrator/Root privileges.")
return
print(f"Unblocking: {', '.join(websites)}")
try:
with open(HOSTS_PATH, 'r') as file:
lines = file.readlines()
with open(HOSTS_PATH, 'w') as file:
for line in lines:
# Check if line contains any of the target websites
# We split the line to ensure we are matching the domain part
parts = line.split()
is_target = False
if len(parts) >= 2 and parts[0] == REDIRECT_IP:
domain = parts[1]
for site in websites:
if domain == site or domain == f"www.{site}":
is_target = True
print(f" Unblocked {domain}")
break
if not is_target:
file.write(line)
except PermissionError:
print("Permission denied. Please run as Administrator/Root.")
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Host File Website Blocker")
subparsers = parser.add_subparsers(dest="command", help="Command to run")
# Block Command
block_parser = subparsers.add_parser("block", help="Block websites")
block_parser.add_argument("websites", nargs="+", help="List of websites to block")
# Unblock Command
unblock_parser = subparsers.add_parser("unblock", help="Unblock websites")
unblock_parser.add_argument("websites", nargs="+", help="List of websites to unblock")
args = parser.parse_args()
if args.command == "block":
block_sites(args.websites)
elif args.command == "unblock":
unblock_sites(args.websites)
else:
parser.print_help()Usage
Windows: Open Command Prompt as Administrator.
Linux/macOS: Use sudo.
# Block Facebook and YouTube
python blocker.py block facebook.com youtube.com
# Unblock them
python blocker.py unblock facebook.com youtube.com