Add cpplint to validate_filenames (#643)

* Add cpplint to validate_filenames

* Update and rename Happy_number.cpp to happy_number.cpp

* Update validate_new_filenames.yml

* pip install cpplint

* python3 -m pip install cpplint

* python3 -m pip install --useer cpplint

* python3 -m pip install --user cpplint

* Update validate_new_filenames.yml

* sudo python3 -m pip install cpplint

* sudo python3 -m pip install cpplint

* uses: actions/setup-python@v1

* Run cpplint first

* cpp_exts

* tuple

* cpplint_modified_files

.github/workflows/cpplint_modified_files.yml

@@ -1,21 +1,34 @@
-name: validate_new_filenames
+name: cpplint_modified_files
 on: [push, pull_request]
 jobs:
-  validate_new_filenames:
+  cpplint_modified_files:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v1
+      - uses: actions/setup-python@v1
+      - run: python -m pip install cpplint
       - run: git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY
       - run: git diff origin/master --name-only > git_diff.txt
-      - name: Validate new filenames
+      - name: cpplint_modified_files
         shell: python
         run: |
           import os
+          import subprocess
           import sys
-          print(sys.version_info)  # legacy Python :-(
+
+          print("Python {}.{}.{}".format(*sys.version_info))  # legacy Python :-(
           with open("git_diff.txt") as in_file:
-            cpp_files = sorted(line.strip() for line in in_file
-                               if line.strip().lower().endswith(".cpp"))
+            modified_files = sorted(in_file.read().splitlines())
+          print("{} files were modified.".format(len(modified_files)))
+
+          cpp_exts = tuple(".c .c++ .cc .cpp .cu .cuh .cxx .h .h++ .hh .hpp .hxx".split())
+          cpp_files = [file for file in modified_files if file.lower().endswith(cpp_exts)]
+          print("{} C++ files were modified.".format(len(cpp_files)))
+          if not cpp_files:
+            sys.exit(0)
+
+          print("cpplint:")
+          print(subprocess.check_output(["cpplint"] + cpp_files).decode("utf-8"))
 
           upper_files = [file for file in cpp_files if os.path.basename(file) != os.path.basename(file).lower()]
           if upper_files: