184 lines
5.9 KiB
Python
184 lines
5.9 KiB
Python
|
"""Filename matching with shell patterns.
|
||
|
|
||
|
fnmatch(FILENAME, PATTERN) matches according to the local convention.
|
||
|
fnmatchcase(FILENAME, PATTERN) always takes case in account.
|
||
|
|
||
|
The functions operate by translating the pattern into a regular
|
||
|
expression. They cache the compiled regular expressions for speed.
|
||
|
|
||
|
The function translate(PATTERN) returns a regular expression
|
||
|
corresponding to PATTERN. (It does not compile it.)
|
||
|
"""
|
||
|
import os
|
||
|
import posixpath
|
||
|
import re
|
||
|
import functools
|
||
|
|
||
|
__all__ = ["filter", "fnmatch", "fnmatchcase", "translate"]
|
||
|
|
||
|
# Build a thread-safe incrementing counter to help create unique regexp group
|
||
|
# names across calls.
|
||
|
from itertools import count
|
||
|
_nextgroupnum = count().__next__
|
||
|
del count
|
||
|
|
||
|
def fnmatch(name, pat):
|
||
|
"""Test whether FILENAME matches PATTERN.
|
||
|
|
||
|
Patterns are Unix shell style:
|
||
|
|
||
|
* matches everything
|
||
|
? matches any single character
|
||
|
[seq] matches any character in seq
|
||
|
[!seq] matches any char not in seq
|
||
|
|
||
|
An initial period in FILENAME is not special.
|
||
|
Both FILENAME and PATTERN are first case-normalized
|
||
|
if the operating system requires it.
|
||
|
If you don't want this, use fnmatchcase(FILENAME, PATTERN).
|
||
|
"""
|
||
|
name = os.path.normcase(name)
|
||
|
pat = os.path.normcase(pat)
|
||
|
return fnmatchcase(name, pat)
|
||
|
|
||
|
@functools.lru_cache(maxsize=256, typed=True)
|
||
|
def _compile_pattern(pat):
|
||
|
if isinstance(pat, bytes):
|
||
|
pat_str = str(pat, 'ISO-8859-1')
|
||
|
res_str = translate(pat_str)
|
||
|
res = bytes(res_str, 'ISO-8859-1')
|
||
|
else:
|
||
|
res = translate(pat)
|
||
|
return re.compile(res).match
|
||
|
|
||
|
def filter(names, pat):
|
||
|
"""Construct a list from those elements of the iterable NAMES that match PAT."""
|
||
|
result = []
|
||
|
pat = os.path.normcase(pat)
|
||
|
match = _compile_pattern(pat)
|
||
|
if os.path is posixpath:
|
||
|
# normcase on posix is NOP. Optimize it away from the loop.
|
||
|
for name in names:
|
||
|
if match(name):
|
||
|
result.append(name)
|
||
|
else:
|
||
|
for name in names:
|
||
|
if match(os.path.normcase(name)):
|
||
|
result.append(name)
|
||
|
return result
|
||
|
|
||
|
def fnmatchcase(name, pat):
|
||
|
"""Test whether FILENAME matches PATTERN, including case.
|
||
|
|
||
|
This is a version of fnmatch() which doesn't case-normalize
|
||
|
its arguments.
|
||
|
"""
|
||
|
match = _compile_pattern(pat)
|
||
|
return match(name) is not None
|
||
|
|
||
|
|
||
|
def translate(pat):
|
||
|
"""Translate a shell PATTERN to a regular expression.
|
||
|
|
||
|
There is no way to quote meta-characters.
|
||
|
"""
|
||
|
|
||
|
STAR = object()
|
||
|
res = []
|
||
|
add = res.append
|
||
|
i, n = 0, len(pat)
|
||
|
while i < n:
|
||
|
c = pat[i]
|
||
|
i = i+1
|
||
|
if c == '*':
|
||
|
# compress consecutive `*` into one
|
||
|
if (not res) or res[-1] is not STAR:
|
||
|
add(STAR)
|
||
|
elif c == '?':
|
||
|
add('.')
|
||
|
elif c == '[':
|
||
|
j = i
|
||
|
if j < n and pat[j] == '!':
|
||
|
j = j+1
|
||
|
if j < n and pat[j] == ']':
|
||
|
j = j+1
|
||
|
while j < n and pat[j] != ']':
|
||
|
j = j+1
|
||
|
if j >= n:
|
||
|
add('\\[')
|
||
|
else:
|
||
|
stuff = pat[i:j]
|
||
|
if '--' not in stuff:
|
||
|
stuff = stuff.replace('\\', r'\\')
|
||
|
else:
|
||
|
chunks = []
|
||
|
k = i+2 if pat[i] == '!' else i+1
|
||
|
while True:
|
||
|
k = pat.find('-', k, j)
|
||
|
if k < 0:
|
||
|
break
|
||
|
chunks.append(pat[i:k])
|
||
|
i = k+1
|
||
|
k = k+3
|
||
|
chunks.append(pat[i:j])
|
||
|
# Escape backslashes and hyphens for set difference (--).
|
||
|
# Hyphens that create ranges shouldn't be escaped.
|
||
|
stuff = '-'.join(s.replace('\\', r'\\').replace('-', r'\-')
|
||
|
for s in chunks)
|
||
|
# Escape set operations (&&, ~~ and ||).
|
||
|
stuff = re.sub(r'([&~|])', r'\\\1', stuff)
|
||
|
i = j+1
|
||
|
if stuff[0] == '!':
|
||
|
stuff = '^' + stuff[1:]
|
||
|
elif stuff[0] in ('^', '['):
|
||
|
stuff = '\\' + stuff
|
||
|
add(f'[{stuff}]')
|
||
|
else:
|
||
|
add(re.escape(c))
|
||
|
assert i == n
|
||
|
|
||
|
# Deal with STARs.
|
||
|
inp = res
|
||
|
res = []
|
||
|
add = res.append
|
||
|
i, n = 0, len(inp)
|
||
|
# Fixed pieces at the start?
|
||
|
while i < n and inp[i] is not STAR:
|
||
|
add(inp[i])
|
||
|
i += 1
|
||
|
# Now deal with STAR fixed STAR fixed ...
|
||
|
# For an interior `STAR fixed` pairing, we want to do a minimal
|
||
|
# .*? match followed by `fixed`, with no possibility of backtracking.
|
||
|
# We can't spell that directly, but can trick it into working by matching
|
||
|
# .*?fixed
|
||
|
# in a lookahead assertion, save the matched part in a group, then
|
||
|
# consume that group via a backreference. If the overall match fails,
|
||
|
# the lookahead assertion won't try alternatives. So the translation is:
|
||
|
# (?=(?P<name>.*?fixed))(?P=name)
|
||
|
# Group names are created as needed: g0, g1, g2, ...
|
||
|
# The numbers are obtained from _nextgroupnum() to ensure they're unique
|
||
|
# across calls and across threads. This is because people rely on the
|
||
|
# undocumented ability to join multiple translate() results together via
|
||
|
# "|" to build large regexps matching "one of many" shell patterns.
|
||
|
while i < n:
|
||
|
assert inp[i] is STAR
|
||
|
i += 1
|
||
|
if i == n:
|
||
|
add(".*")
|
||
|
break
|
||
|
assert inp[i] is not STAR
|
||
|
fixed = []
|
||
|
while i < n and inp[i] is not STAR:
|
||
|
fixed.append(inp[i])
|
||
|
i += 1
|
||
|
fixed = "".join(fixed)
|
||
|
if i == n:
|
||
|
add(".*")
|
||
|
add(fixed)
|
||
|
else:
|
||
|
groupnum = _nextgroupnum()
|
||
|
add(f"(?=(?P<g{groupnum}>.*?{fixed}))(?P=g{groupnum})")
|
||
|
assert i == n
|
||
|
res = "".join(res)
|
||
|
return fr'(?s:{res})\Z'
|