Add urllib as a fallback to link checker along with curl

.github/workflows/pr_checks.yml

@@ -38,6 +38,7 @@ jobs:
               run-spelling-check: true,
               run-complexity: false,
               run-doxygen: false,
+              exclude-dirs: 'source/portable/NetworkInterface/STM32'
             },
             {
               repository: FreeRTOS,
@@ -47,7 +48,7 @@ jobs:
               run-spelling-check: true,
               run-complexity: false,
               run-doxygen: false,
-              exclude-dirs: ethernet, drivers, FreeRTOS/Demo,
+              exclude-dirs: 'ethernet, drivers, FreeRTOS/Demo'
             },
             {
               repository: backoffAlgorithm,
@@ -246,7 +247,7 @@ jobs:
         uses: ./spellings
         with:
           path: repo/${{ matrix.inputs.repository }}
-          exclude-dirs: ${{ matrix.inputs.repository }}
+          exclude-dirs: ${{ matrix.inputs.exclude-dirs }}
 
       - name: "Recursive Clone: ${{ matrix.inputs.repository }}"
         if: success() || failure()
@@ -349,6 +350,7 @@ jobs:
               repository: FreeRTOS-Plus-TCP,
               org: FreeRTOS,
               branch: main,
+              exclude-dirs: 'source/portable/NetworkInterface/STM32'
             },
             {
               repository: FreeRTOS,

link-verifier/verify-links.py

@@ -5,6 +5,7 @@
 import time
 import argparse
 import re
+import urllib
 import subprocess
 import requests
 import shutil
@@ -256,6 +257,16 @@ def access_url(url):
             is_broken = False
             status = http_status_code
 
+    # Use urllib as a fallback.
+    if is_broken == True:
+        req = urllib.request.Request(url, headers=http_headers)
+        try:
+            response = urllib.request.urlopen(req)
+            is_broken = False
+            status = response.getcode()
+        except (urllib.error.HTTPError, urllib.error.URLError) as e:
+            print(f"urllib: {url} error: {e}")
+
     return is_broken, status
 
 def test_url(url):