From d93249eeab12f18563b895da3113715234f157c3 Mon Sep 17 00:00:00 2001
From: Arne Welzel <arne.welzel@corelight.com>
Date: Fri, 6 Dec 2024 12:43:39 +0100
Subject: [PATCH] pre-commit: Add license-header check inspired by Spicy

---
 .pre-commit-config.yaml | 11 +++++++++++
 ci/license-header.py    | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100755 ci/license-header.py

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 1997a9be57..b0fc21d692 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -2,6 +2,17 @@
 # See https://pre-commit.com/hooks.html for more hooks
 #
 repos:
+- repo: local
+  hooks:
+  - id: license
+    name: Check for license headers
+    entry: ./ci/license-header.py
+    language: python
+    types_or:
+      - "c"
+      - "c++"
+    exclude: '^(testing/btest/plugins/.*|testing/builtin-plugins/.*)$'
+
 - repo: https://github.com/pre-commit/mirrors-clang-format
   rev: 'v18.1.8'
   hooks:
diff --git a/ci/license-header.py b/ci/license-header.py
new file mode 100755
index 0000000000..2af95aba0c
--- /dev/null
+++ b/ci/license-header.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+
+import sys
+import re
+
+exit_code = 0
+
+pat1 = re.compile(r"See the file \"COPYING\" in the main distribution directory for copyright.")
+
+# This is the copyright line used within Spicy plugin and popular in
+# Spicy analyzers.
+pat2 = re.compile(r"Copyright \(c\) 2... by the Zeek Project. See COPYING for details.")
+
+
+def match_line(line):
+    for pat in [pat1, pat2]:
+        m = pat.search(line)
+        if m is not None:
+            return True
+
+    return False
+
+
+for f in sys.argv[1:]:
+    has_license_header = False
+    with open(f) as fp:
+        for line in fp:
+            line = line.strip()
+            if has_license_header := match_line(line):
+                break
+
+    if not has_license_header:
+        print(f"{f}:does not seem to contain a license header", file=sys.stderr)
+        exit_code = 1
+
+sys.exit(exit_code)