1"""Filename matching with shell patterns.
2
3fnmatch(FILENAME, PATTERN) matches according to the local convention.
4fnmatchcase(FILENAME, PATTERN) always takes case in account.
5
6The functions operate by translating the pattern into a regular
7expression.  They cache the compiled regular expressions for speed.
8
9The function translate(PATTERN) returns a regular expression
10corresponding to PATTERN.  (It does not compile it.)
11"""
12import os
13import posixpath
14import re
15import functools
16
17__all__ = ["filter", "fnmatch", "fnmatchcase", "translate"]
18
19def fnmatch(name, pat):
20    """Test whether FILENAME matches PATTERN.
21
22    Patterns are Unix shell style:
23
24    *       matches everything
25    ?       matches any single character
26    [seq]   matches any character in seq
27    [!seq]  matches any char not in seq
28
29    An initial period in FILENAME is not special.
30    Both FILENAME and PATTERN are first case-normalized
31    if the operating system requires it.
32    If you don't want this, use fnmatchcase(FILENAME, PATTERN).
33    """
34    name = os.path.normcase(name)
35    pat = os.path.normcase(pat)
36    return fnmatchcase(name, pat)
37
38@functools.lru_cache(maxsize=256, typed=True)
39def _compile_pattern(pat):
40    if isinstance(pat, bytes):
41        pat_str = str(pat, 'ISO-8859-1')
42        res_str = translate(pat_str)
43        res = bytes(res_str, 'ISO-8859-1')
44    else:
45        res = translate(pat)
46    return re.compile(res).match
47
48def filter(names, pat):
49    """Construct a list from those elements of the iterable NAMES that match PAT."""
50    result = []
51    pat = os.path.normcase(pat)
52    match = _compile_pattern(pat)
53    if os.path is posixpath:
54        # normcase on posix is NOP. Optimize it away from the loop.
55        for name in names:
56            if match(name):
57                result.append(name)
58    else:
59        for name in names:
60            if match(os.path.normcase(name)):
61                result.append(name)
62    return result
63
64def fnmatchcase(name, pat):
65    """Test whether FILENAME matches PATTERN, including case.
66
67    This is a version of fnmatch() which doesn't case-normalize
68    its arguments.
69    """
70    match = _compile_pattern(pat)
71    return match(name) is not None
72
73
74def translate(pat):
75    """Translate a shell PATTERN to a regular expression.
76
77    There is no way to quote meta-characters.
78    """
79
80    i, n = 0, len(pat)
81    res = ''
82    while i < n:
83        c = pat[i]
84        i = i+1
85        if c == '*':
86            res = res + '.*'
87        elif c == '?':
88            res = res + '.'
89        elif c == '[':
90            j = i
91            if j < n and pat[j] == '!':
92                j = j+1
93            if j < n and pat[j] == ']':
94                j = j+1
95            while j < n and pat[j] != ']':
96                j = j+1
97            if j >= n:
98                res = res + '\\['
99            else:
100                stuff = pat[i:j]
101                if '--' not in stuff:
102                    stuff = stuff.replace('\\', r'\\')
103                else:
104                    chunks = []
105                    k = i+2 if pat[i] == '!' else i+1
106                    while True:
107                        k = pat.find('-', k, j)
108                        if k < 0:
109                            break
110                        chunks.append(pat[i:k])
111                        i = k+1
112                        k = k+3
113                    chunks.append(pat[i:j])
114                    # Escape backslashes and hyphens for set difference (--).
115                    # Hyphens that create ranges shouldn't be escaped.
116                    stuff = '-'.join(s.replace('\\', r'\\').replace('-', r'\-')
117                                     for s in chunks)
118                # Escape set operations (&&, ~~ and ||).
119                stuff = re.sub(r'([&~|])', r'\\\1', stuff)
120                i = j+1
121                if stuff[0] == '!':
122                    stuff = '^' + stuff[1:]
123                elif stuff[0] in ('^', '['):
124                    stuff = '\\' + stuff
125                res = '%s[%s]' % (res, stuff)
126        else:
127            res = res + re.escape(c)
128    return r'(?s:%s)\Z' % res
129