| """Utilities for comparing files and directories.
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|
|
| Classes:
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| dircmp
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|
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| Functions:
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| cmp(f1, f2, shallow=1) -> int
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| cmpfiles(a, b, common) -> ([], [], [])
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|
|
| """
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|
|
| import os
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| import stat
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| from itertools import ifilter, ifilterfalse, imap, izip
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|
|
| __all__ = ["cmp","dircmp","cmpfiles"]
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|
|
| _cache = {}
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| BUFSIZE=8*1024
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|
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| def cmp(f1, f2, shallow=1):
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| """Compare two files.
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|
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| Arguments:
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|
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| f1 -- First file name
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|
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| f2 -- Second file name
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|
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| shallow -- Just check stat signature (do not read the files).
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| defaults to 1.
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|
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| Return value:
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|
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| True if the files are the same, False otherwise.
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|
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| This function uses a cache for past comparisons and the results,
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| with a cache invalidation mechanism relying on stale signatures.
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|
|
| """
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|
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| s1 = _sig(os.stat(f1))
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| s2 = _sig(os.stat(f2))
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| if s1[0] != stat.S_IFREG or s2[0] != stat.S_IFREG:
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| return False
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| if shallow and s1 == s2:
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| return True
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| if s1[1] != s2[1]:
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| return False
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|
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| result = _cache.get((f1, f2))
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| if result and (s1, s2) == result[:2]:
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| return result[2]
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| outcome = _do_cmp(f1, f2)
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| _cache[f1, f2] = s1, s2, outcome
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| return outcome
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|
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| def _sig(st):
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| return (stat.S_IFMT(st.st_mode),
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| st.st_size,
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| st.st_mtime)
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|
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| def _do_cmp(f1, f2):
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| bufsize = BUFSIZE
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| with open(f1, 'rb') as fp1, open(f2, 'rb') as fp2:
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| while True:
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| b1 = fp1.read(bufsize)
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| b2 = fp2.read(bufsize)
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| if b1 != b2:
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| return False
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| if not b1:
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| return True
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|
|
| # Directory comparison class.
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| #
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| class dircmp:
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| """A class that manages the comparison of 2 directories.
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|
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| dircmp(a,b,ignore=None,hide=None)
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| A and B are directories.
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| IGNORE is a list of names to ignore,
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| defaults to ['RCS', 'CVS', 'tags'].
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| HIDE is a list of names to hide,
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| defaults to [os.curdir, os.pardir].
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|
|
| High level usage:
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| x = dircmp(dir1, dir2)
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| x.report() -> prints a report on the differences between dir1 and dir2
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| or
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| x.report_partial_closure() -> prints report on differences between dir1
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| and dir2, and reports on common immediate subdirectories.
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| x.report_full_closure() -> like report_partial_closure,
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| but fully recursive.
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|
|
| Attributes:
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| left_list, right_list: The files in dir1 and dir2,
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| filtered by hide and ignore.
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| common: a list of names in both dir1 and dir2.
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| left_only, right_only: names only in dir1, dir2.
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| common_dirs: subdirectories in both dir1 and dir2.
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| common_files: files in both dir1 and dir2.
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| common_funny: names in both dir1 and dir2 where the type differs between
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| dir1 and dir2, or the name is not stat-able.
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| same_files: list of identical files.
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| diff_files: list of filenames which differ.
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| funny_files: list of files which could not be compared.
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| subdirs: a dictionary of dircmp objects, keyed by names in common_dirs.
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| """
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|
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| def __init__(self, a, b, ignore=None, hide=None): # Initialize
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| self.left = a
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| self.right = b
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| if hide is None:
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| self.hide = [os.curdir, os.pardir] # Names never to be shown
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| else:
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| self.hide = hide
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| if ignore is None:
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| self.ignore = ['RCS', 'CVS', 'tags'] # Names ignored in comparison
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| else:
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| self.ignore = ignore
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|
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| def phase0(self): # Compare everything except common subdirectories
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| self.left_list = _filter(os.listdir(self.left),
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| self.hide+self.ignore)
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| self.right_list = _filter(os.listdir(self.right),
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| self.hide+self.ignore)
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| self.left_list.sort()
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| self.right_list.sort()
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|
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| def phase1(self): # Compute common names
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| a = dict(izip(imap(os.path.normcase, self.left_list), self.left_list))
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| b = dict(izip(imap(os.path.normcase, self.right_list), self.right_list))
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| self.common = map(a.__getitem__, ifilter(b.__contains__, a))
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| self.left_only = map(a.__getitem__, ifilterfalse(b.__contains__, a))
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| self.right_only = map(b.__getitem__, ifilterfalse(a.__contains__, b))
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|
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| def phase2(self): # Distinguish files, directories, funnies
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| self.common_dirs = []
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| self.common_files = []
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| self.common_funny = []
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|
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| for x in self.common:
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| a_path = os.path.join(self.left, x)
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| b_path = os.path.join(self.right, x)
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|
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| ok = 1
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| try:
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| a_stat = os.stat(a_path)
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| except os.error, why:
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| # print 'Can\'t stat', a_path, ':', why[1]
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| ok = 0
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| try:
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| b_stat = os.stat(b_path)
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| except os.error, why:
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| # print 'Can\'t stat', b_path, ':', why[1]
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| ok = 0
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|
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| if ok:
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| a_type = stat.S_IFMT(a_stat.st_mode)
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| b_type = stat.S_IFMT(b_stat.st_mode)
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| if a_type != b_type:
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| self.common_funny.append(x)
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| elif stat.S_ISDIR(a_type):
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| self.common_dirs.append(x)
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| elif stat.S_ISREG(a_type):
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| self.common_files.append(x)
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| else:
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| self.common_funny.append(x)
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| else:
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| self.common_funny.append(x)
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|
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| def phase3(self): # Find out differences between common files
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| xx = cmpfiles(self.left, self.right, self.common_files)
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| self.same_files, self.diff_files, self.funny_files = xx
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|
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| def phase4(self): # Find out differences between common subdirectories
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| # A new dircmp object is created for each common subdirectory,
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| # these are stored in a dictionary indexed by filename.
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| # The hide and ignore properties are inherited from the parent
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| self.subdirs = {}
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| for x in self.common_dirs:
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| a_x = os.path.join(self.left, x)
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| b_x = os.path.join(self.right, x)
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| self.subdirs[x] = dircmp(a_x, b_x, self.ignore, self.hide)
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|
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| def phase4_closure(self): # Recursively call phase4() on subdirectories
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| self.phase4()
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| for sd in self.subdirs.itervalues():
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| sd.phase4_closure()
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|
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| def report(self): # Print a report on the differences between a and b
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| # Output format is purposely lousy
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| print 'diff', self.left, self.right
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| if self.left_only:
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| self.left_only.sort()
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| print 'Only in', self.left, ':', self.left_only
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| if self.right_only:
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| self.right_only.sort()
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| print 'Only in', self.right, ':', self.right_only
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| if self.same_files:
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| self.same_files.sort()
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| print 'Identical files :', self.same_files
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| if self.diff_files:
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| self.diff_files.sort()
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| print 'Differing files :', self.diff_files
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| if self.funny_files:
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| self.funny_files.sort()
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| print 'Trouble with common files :', self.funny_files
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| if self.common_dirs:
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| self.common_dirs.sort()
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| print 'Common subdirectories :', self.common_dirs
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| if self.common_funny:
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| self.common_funny.sort()
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| print 'Common funny cases :', self.common_funny
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|
|
| def report_partial_closure(self): # Print reports on self and on subdirs
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| self.report()
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| for sd in self.subdirs.itervalues():
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| print
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| sd.report()
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|
|
| def report_full_closure(self): # Report on self and subdirs recursively
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| self.report()
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| for sd in self.subdirs.itervalues():
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| print
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| sd.report_full_closure()
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|
|
| methodmap = dict(subdirs=phase4,
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| same_files=phase3, diff_files=phase3, funny_files=phase3,
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| common_dirs = phase2, common_files=phase2, common_funny=phase2,
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| common=phase1, left_only=phase1, right_only=phase1,
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| left_list=phase0, right_list=phase0)
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|
|
| def __getattr__(self, attr):
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| if attr not in self.methodmap:
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| raise AttributeError, attr
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| self.methodmap[attr](self)
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| return getattr(self, attr)
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|
|
| def cmpfiles(a, b, common, shallow=1):
|
| """Compare common files in two directories.
|
|
|
| a, b -- directory names
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| common -- list of file names found in both directories
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| shallow -- if true, do comparison based solely on stat() information
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|
|
| Returns a tuple of three lists:
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| files that compare equal
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| files that are different
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| filenames that aren't regular files.
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|
|
| """
|
| res = ([], [], [])
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| for x in common:
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| ax = os.path.join(a, x)
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| bx = os.path.join(b, x)
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| res[_cmp(ax, bx, shallow)].append(x)
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| return res
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|
|
|
|
| # Compare two files.
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| # Return:
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| # 0 for equal
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| # 1 for different
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| # 2 for funny cases (can't stat, etc.)
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| #
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| def _cmp(a, b, sh, abs=abs, cmp=cmp):
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| try:
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| return not abs(cmp(a, b, sh))
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| except os.error:
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| return 2
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|
|
|
|
| # Return a copy with items that occur in skip removed.
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| #
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| def _filter(flist, skip):
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| return list(ifilterfalse(skip.__contains__, flist))
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|
|
|
|
| # Demonstration and testing.
|
| #
|
| def demo():
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| import sys
|
| import getopt
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| options, args = getopt.getopt(sys.argv[1:], 'r')
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| if len(args) != 2:
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| raise getopt.GetoptError('need exactly two args', None)
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| dd = dircmp(args[0], args[1])
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| if ('-r', '') in options:
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| dd.report_full_closure()
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| else:
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| dd.report()
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|
|
| if __name__ == '__main__':
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| demo()
|