code: def check_signing_file(self, keyid, signing_file):
          '''
          Check a keyid for membership in a signing file
          '''
          if not signing_file or not os.path.exists(signing_file):
              return False
  
          if not self.check_permissions(signing_file):
              log.warning('Wrong permissions for %s, ignoring content', signing_file)
              return False
  
          mtime = os.path.getmtime(signing_file)
          if self.signing_files.get(signing_file, {}).get('mtime') != mtime:
              self.signing_files.setdefault(signing_file, {})['mtime'] = mtime
              with salt.utils.files.fopen(signing_file, 'r') as fp_:
                  self.signing_files[signing_file]['data'] = [
                      entry for entry in [line.strip() for line in fp_] if not entry.strip().startswith('#')
                  ]
          return any(salt.utils.stringutils.expr_match(keyid, line) for line
                     in self.signing_files[signing_file].get('data', [])f check_signing_file(self, keyid, signing_file):
          '''
          Check a keyid for membership in a signing file
          '''
          if not signing_file or not os.path.exists(signing_file):
              return False
  
          if not self.check_permissions(signing_file):
              log.warning('Wrong permissions for %s, ignoring content', signing_file)
              return False
  
          mtime = os.path.getmtime(signing_file)
          if self.signing_files.get(signing_file, {}).get('mtime') != mtime:
              self.signing_files.setdefault(signing_file, {})['mtime'] = mtime
              with salt.utils.files.fopen(signing_file, 'r') as fp_:
                  self.signing_files[signing_file]['data'] = [
                      entry for entry in [line.strip() for line in fp_] if not entry.strip().startswith('#')
                  ]
          return any(salt.utils.stringutils.expr_match(keyid, line) for line
                     in self.signing_files[signing_file].get('data', []))
docs: Check a keyid for membership in a signing file