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    if not pat in _cache:
51        res = translate(pat)
52        if len(_cache) >= _MAXCACHE:
53            _cache.clear()
54        _cache[pat] = re.compile(res)
55    match=_cache[pat].match
56    if os.path is posixpath:
57        # normcase on posix is NOP. Optimize it away from the loop.
58        for name in names:
59            if match(name):
60                result.append(name)
61    else:
62        for name in names:
63            if match(os.path.normcase(name)):
64                result.append(name)
65    return result
66
67def fnmatchcase(name, pat):
68    """Test whether FILENAME matches PATTERN, including case.
69
70    This is a version of fnmatch() which doesn't case-normalize
71    its arguments.
72    """
73
74    if not pat in _cache:
75        res = translate(pat)
76        if len(_cache) >= _MAXCACHE:
77            _cache.clear()
78        _cache[pat] = re.compile(res)
79    return _cache[pat].match(name) is not None
80
81def translate(pat):
82    """Translate a shell PATTERN to a regular expression.
83
84    There is no way to quote meta-characters.
85    """
86
87    i, n = 0, len(pat)
88    res = ''
89    while i < n:
90        c = pat[i]
91        i = i+1
92        if c == '*':
93            res = res + '.*'
94        elif c == '?':
95            res = res + '.'
96        elif c == '[':
97            j = i
98            if j < n and pat[j] == '!':
99                j = j+1
100            if j < n and pat[j] == ']':
101                j = j+1
102            while j < n and pat[j] != ']':
103                j = j+1
104            if j >= n:
105                res = res + '\\['
106            else:
107                stuff = pat[i:j].replace('\\','\\\\')
108                i = j+1
109                if stuff[0] == '!':
110                    stuff = '^' + stuff[1:]
111                elif stuff[0] == '^':
112                    stuff = '\\' + stuff
113                res = '%s[%s]' % (res, stuff)
114        else:
115            res = res + re.escape(c)
116    return res + '\Z(?ms)'
117