Just a bunch of handy methods for dealing with files and paths:
FileExists::fileExists($path):\ A well-behaved version of file_exists that throws upon failure rather than emitting a warning
FileExists::fileExistsTryHarder($path):\ Also well-behaved. Tries FileExists::fileExists(). In case of failure, tries exec()-based implementation
PathValidator::checkPath($path):\ Check if path looks valid and doesn't contain suspecious patterns
PathValidator::checkFilePathIsRegularFile($path):\ Check if path points to a regular file (and doesnt match suspecious patterns)