02-detect-broken-symlinks.py

#!/usr/bin/env python3
""" Recursively walk the current working directory looking for broken
symlinks. If any broken symlinks are found print out a report and exit
with status 1. If none are found exit with status 0.

"""
import sys
import os
from pathlib import Path
import subprocess


def _resolve(path):
    try:
        return path.resolve(False)
    except TypeError:
        # fallback for py < 3.6
        try:
            return path.resolve()
        except FileNotFoundError:
            return Path(os.readlink(str(path)))


broken = []
files = subprocess.check_output(['git', 'ls-files'], universal_newlines=True)
root = os.getcwd()
for filename in files.splitlines():
    path = Path(os.path.join(root, filename))
    if path.is_symlink():
        target = _resolve(path)
        # exists already checks if the pointed to file is there
        if not path.exists():
            broken.append('{} --> {}'.format(path, target))
    else:
        # If it's not a symlink we're not interested.
        continue

if len(broken) == 0:
    sys.exit(0)

print('\nbroken symlink(s) found: {}'.format('\n'.join(broken)), file=sys.stderr)
sys.exit(1)