globber.py

# Copyright 2019 Jaakko Kangasharju
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# This file has been altered from its original form.

import re

_double_star_after_invalid_regex = re.compile(r'[^/\\]\*\*')
_double_star_first_before_invalid_regex = re.compile('^\\*\\*[^/]')
_double_star_middle_before_invalid_regex = re.compile(r'[^\\]\*\*[^/]')


def _match_component(pattern_component, file_name_component):
    if len(pattern_component) == 0 and len(file_name_component) == 0:
        return True
    elif len(pattern_component) == 0:
        return False
    elif len(file_name_component) == 0:
        return pattern_component == '*'
    elif pattern_component[0] == '*':
        return _match_component(pattern_component, file_name_component[1:]) or _match_component(pattern_component[1:],
                                                                                                file_name_component)
    elif pattern_component[0] == '?':
        return _match_component(pattern_component[1:], file_name_component[1:])
    elif pattern_component[0] == '\\':
        return len(pattern_component) >= 2 and pattern_component[1] == file_name_component[0] and _match_component(
            pattern_component[2:], file_name_component[1:])
    elif pattern_component[0] != file_name_component[0]:
        return False
    else:
        return _match_component(pattern_component[1:], file_name_component[1:])


def _match_components(pattern_components, file_name_components):
    if len(pattern_components) == 0 and len(file_name_components) == 0:
        return True
    if len(pattern_components) == 0:
        return False
    if len(file_name_components) == 0:
        return len(pattern_components) == 1 and pattern_components[0] == '**'
    if pattern_components[0] == '**':
        return _match_components(pattern_components, file_name_components[1:]) or _match_components(
            pattern_components[1:], file_name_components)
    else:
        return _match_component(pattern_components[0], file_name_components[0]) and _match_components(
            pattern_components[1:], file_name_components[1:])


def match(pattern, file_name):
    """Match a glob pattern against a file name.

    Glob pattern matching is for file names, which do not need to exist as files on the file system.
    A file name is a sequence of directory names, possibly followed by the name of a file, with the
    components separated by a path separator. A glob pattern is similar, except it may contain special
    characters: A '?' matches any character in a name. A '*' matches any sequence of characters (possibly
    empty) in a name. Both of these match only within a single component, i.e., they will not match a
    path separator. A component in a pattern may also be a literal '**', which matches zero or more
    components in the complete file name. A backslash '\\' in a pattern acts as an escape character,
    and indicates that the following character is to be matched literally, even if it is a special
    character.

    :param pattern: The pattern to match. The path separator in patterns is always '/'.
    :param file_name: The file name to match against. The path separator in file names is the platform separator
    :return: True if the pattern matches, False otherwise
    """
    if _double_star_after_invalid_regex.search(pattern) is not None or _double_star_first_before_invalid_regex.search(
            pattern) is not None or _double_star_middle_before_invalid_regex.search(pattern) is not None:
        raise ValueError('** in {} not alone between path separators'.format(pattern))
    pattern = pattern.rstrip('/')
    file_name = file_name.rstrip('/')
    while '**/**' in pattern:
        pattern = pattern.replace('**/**', '**')
    pattern_components = pattern.split('/')
    # We split on '\' as well as '/' to support unix and windows-style paths
    file_name_components = re.split(r'[\\/]', file_name)
    return _match_components(pattern_components, file_name_components)