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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"""
12
13import re
14
15__all__ = ["filter", "fnmatch", "fnmatchcase", "translate"]
16
17_cache = {}
18_MAXCACHE = 100
19
20def _purge():
21    """Clear the pattern cache"""
22    _cache.clear()
23
24def fnmatch(name, pat):
25    """Test whether FILENAME matches PATTERN.
26
27    Patterns are Unix shell style:
28
29    *       matches everything
30    ?       matches any single character
31    [seq]   matches any character in seq
32    [!seq]  matches any char not in seq
33
34    An initial period in FILENAME is not special.
35    Both FILENAME and PATTERN are first case-normalized
36    if the operating system requires it.
37    If you don't want this, use fnmatchcase(FILENAME, PATTERN).
38    """
39
40    import os
41    name = os.path.normcase(name)
42    pat = os.path.normcase(pat)
43    return fnmatchcase(name, pat)
44
45def filter(names, pat):
46    """Return the subset of the list NAMES that match PAT"""
47    import os,posixpath
48    result=[]
49    pat=os.path.normcase(pat)
50    try:
51        re_pat = _cache[pat]
52    except KeyError:
53        res = translate(pat)
54        if len(_cache) >= _MAXCACHE:
55            _cache.clear()
56        _cache[pat] = re_pat = re.compile(res)
57    match = re_pat.match
58    if os.path is posixpath:
59        # normcase on posix is NOP. Optimize it away from the loop.
60        for name in names:
61            if match(name):
62                result.append(name)
63    else:
64        for name in names:
65            if match(os.path.normcase(name)):
66                result.append(name)
67    return result
68
69def fnmatchcase(name, pat):
70    """Test whether FILENAME matches PATTERN, including case.
71
72    This is a version of fnmatch() which doesn't case-normalize
73    its arguments.
74    """
75
76    try:
77        re_pat = _cache[pat]
78    except KeyError:
79        res = translate(pat)
80        if len(_cache) >= _MAXCACHE:
81            _cache.clear()
82        _cache[pat] = re_pat = re.compile(res)
83    return re_pat.match(name) is not None
84
85def translate(pat):
86    """Translate a shell PATTERN to a regular expression.
87
88    There is no way to quote meta-characters.
89    """
90
91    i, n = 0, len(pat)
92    res = ''
93    while i < n:
94        c = pat[i]
95        i = i+1
96        if c == '*':
97            res = res + '.*'
98        elif c == '?':
99            res = res + '.'
100        elif c == '[':
101            j = i
102            if j < n and pat[j] == '!':
103                j = j+1
104            if j < n and pat[j] == ']':
105                j = j+1
106            while j < n and pat[j] != ']':
107                j = j+1
108            if j >= n:
109                res = res + '\\['
110            else:
111                stuff = pat[i:j].replace('\\','\\\\')
112                i = j+1
113                if stuff[0] == '!':
114                    stuff = '^' + stuff[1:]
115                elif stuff[0] == '^':
116                    stuff = '\\' + stuff
117                res = '%s[%s]' % (res, stuff)
118        else:
119            res = res + re.escape(c)
120    return res + '\Z(?ms)'
121