ajout port scanner

cheat_cheat/socket.md

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+The `socket` module is where Python stops being polite and starts speaking raw network 🧩📡
+Here’s a **clean, practical cheat sheet** you’ll actually use when building cyber tools.
+
+---
+
+# 🐍 `socket` Cheat Sheet (Cybersecurity Edition)
+
+## 🔌 Create a Socket
+
+```python
+import socket
+
+s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+```
+
+* `AF_INET` → IPv4
+* `SOCK_STREAM` → TCP
+* (use `SOCK_DGRAM` for UDP)
+
+---
+
+## 🌐 Connect to a Target (Client)
+
+```python
+s.connect(("127.0.0.1", 80))
+```
+
+👉 Used in:
+
+* Port scanners
+* Banner grabbing
+
+---
+
+## 📤 Send Data
+
+```python
+s.send(b"GET / HTTP/1.1\r\nHost: example.com\r\n\r\n")
+```
+
+* Must be **bytes** (`b""`)
+
+---
+
+## 📥 Receive Data
+
+```python
+response = s.recv(1024)
+print(response.decode())
+```
+
+* `1024` = buffer size
+
+---
+
+## ❌ Close Connection
+
+```python
+s.close()
+```
+
+---
+
+# 🔍 Port Scanner Example (core pattern)
+
+```python
+import socket
+
+target = "127.0.0.1"
+
+for port in range(1, 1025):
+    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    s.settimeout(2)
+
+    result = s.connect_ex((target, port))
+
+    if result == 0:
+        print(f"Port {port} is open")
+
+    s.close()
+```
+
+🔥 Key trick:
+
+* `connect_ex()` returns `0` if open (no crash, cleaner)
+
+---
+
+# ⏱️ Timeout (avoid freezing forever)
+
+```python
+s.settimeout(1)
+```
+
+Without this, your scanner becomes a fossil 🦴
+
+---
+
+# 🖥️ Simple Server (Listener)
+
+```python
+import socket
+
+s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+s.bind(("0.0.0.0", 4444))
+s.listen(1)
+
+conn, addr = s.accept()
+print(f"Connection from {addr}")
+
+data = conn.recv(1024)
+print(data.decode())
+
+conn.close()
+```
+
+👉 Used in:
+
+* Backdoor simulations
+* Reverse shells (ethical labs only)
+
+---
+
+# 📡 UDP Socket (connectionless)
+
+```python
+s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+
+s.sendto(b"Hello", ("127.0.0.1", 53))
+```
+
+---
+
+# 🧠 Useful Methods Quick List
+
+* `socket()` → create socket
+* `connect()` → connect to server
+* `connect_ex()` → safer connect
+* `send()` / `sendall()` → send data
+* `recv()` → receive data
+* `bind()` → attach to IP/port
+* `listen()` → wait for connections
+* `accept()` → accept connection
+* `close()` → close socket
+
+---
+
+# ⚠️ Common Mistakes
+
+* Forgetting `.close()` → zombie sockets
+* Not using timeout → slow scans
+* Sending string instead of bytes → 💥 error
+* Scanning too fast → gets blocked