| """Utilities for comparing files and directories. |
| |
| Classes: |
| dircmp |
| |
| Functions: |
| cmp(f1, f2, shallow=1) -> int |
| cmpfiles(a, b, common) -> ([], [], []) |
| |
| """ |
| |
| import os |
| import stat |
| from itertools import ifilter, ifilterfalse, imap, izip |
| |
| __all__ = ["cmp","dircmp","cmpfiles"] |
| |
| _cache = {} |
| BUFSIZE=8*1024 |
| |
| def cmp(f1, f2, shallow=1): |
| """Compare two files. |
| |
| Arguments: |
| |
| f1 -- First file name |
| |
| f2 -- Second file name |
| |
| shallow -- Just check stat signature (do not read the files). |
| defaults to 1. |
| |
| Return value: |
| |
| True if the files are the same, False otherwise. |
| |
| This function uses a cache for past comparisons and the results, |
| with a cache invalidation mechanism relying on stale signatures. |
| |
| """ |
| |
| s1 = _sig(os.stat(f1)) |
| s2 = _sig(os.stat(f2)) |
| if s1[0] != stat.S_IFREG or s2[0] != stat.S_IFREG: |
| return False |
| if shallow and s1 == s2: |
| return True |
| if s1[1] != s2[1]: |
| return False |
| |
| outcome = _cache.get((f1, f2, s1, s2)) |
| if outcome is None: |
| outcome = _do_cmp(f1, f2) |
| if len(_cache) > 100: # limit the maximum size of the cache |
| _cache.clear() |
| _cache[f1, f2, s1, s2] = outcome |
| return outcome |
| |
| def _sig(st): |
| return (stat.S_IFMT(st.st_mode), |
| st.st_size, |
| st.st_mtime) |
| |
| def _do_cmp(f1, f2): |
| bufsize = BUFSIZE |
| with open(f1, 'rb') as fp1, open(f2, 'rb') as fp2: |
| while True: |
| b1 = fp1.read(bufsize) |
| b2 = fp2.read(bufsize) |
| if b1 != b2: |
| return False |
| if not b1: |
| return True |
| |
| # Directory comparison class. |
| # |
| class dircmp: |
| """A class that manages the comparison of 2 directories. |
| |
| dircmp(a,b,ignore=None,hide=None) |
| A and B are directories. |
| IGNORE is a list of names to ignore, |
| defaults to ['RCS', 'CVS', 'tags']. |
| HIDE is a list of names to hide, |
| defaults to [os.curdir, os.pardir]. |
| |
| High level usage: |
| x = dircmp(dir1, dir2) |
| x.report() -> prints a report on the differences between dir1 and dir2 |
| or |
| x.report_partial_closure() -> prints report on differences between dir1 |
| and dir2, and reports on common immediate subdirectories. |
| x.report_full_closure() -> like report_partial_closure, |
| but fully recursive. |
| |
| Attributes: |
| left_list, right_list: The files in dir1 and dir2, |
| filtered by hide and ignore. |
| common: a list of names in both dir1 and dir2. |
| left_only, right_only: names only in dir1, dir2. |
| common_dirs: subdirectories in both dir1 and dir2. |
| common_files: files in both dir1 and dir2. |
| common_funny: names in both dir1 and dir2 where the type differs between |
| dir1 and dir2, or the name is not stat-able. |
| same_files: list of identical files. |
| diff_files: list of filenames which differ. |
| funny_files: list of files which could not be compared. |
| subdirs: a dictionary of dircmp objects, keyed by names in common_dirs. |
| """ |
| |
| def __init__(self, a, b, ignore=None, hide=None): # Initialize |
| self.left = a |
| self.right = b |
| if hide is None: |
| self.hide = [os.curdir, os.pardir] # Names never to be shown |
| else: |
| self.hide = hide |
| if ignore is None: |
| self.ignore = ['RCS', 'CVS', 'tags'] # Names ignored in comparison |
| else: |
| self.ignore = ignore |
| |
| def phase0(self): # Compare everything except common subdirectories |
| self.left_list = _filter(os.listdir(self.left), |
| self.hide+self.ignore) |
| self.right_list = _filter(os.listdir(self.right), |
| self.hide+self.ignore) |
| self.left_list.sort() |
| self.right_list.sort() |
| |
| def phase1(self): # Compute common names |
| a = dict(izip(imap(os.path.normcase, self.left_list), self.left_list)) |
| b = dict(izip(imap(os.path.normcase, self.right_list), self.right_list)) |
| self.common = map(a.__getitem__, ifilter(b.__contains__, a)) |
| self.left_only = map(a.__getitem__, ifilterfalse(b.__contains__, a)) |
| self.right_only = map(b.__getitem__, ifilterfalse(a.__contains__, b)) |
| |
| def phase2(self): # Distinguish files, directories, funnies |
| self.common_dirs = [] |
| self.common_files = [] |
| self.common_funny = [] |
| |
| for x in self.common: |
| a_path = os.path.join(self.left, x) |
| b_path = os.path.join(self.right, x) |
| |
| ok = 1 |
| try: |
| a_stat = os.stat(a_path) |
| except os.error, why: |
| # print 'Can\'t stat', a_path, ':', why[1] |
| ok = 0 |
| try: |
| b_stat = os.stat(b_path) |
| except os.error, why: |
| # print 'Can\'t stat', b_path, ':', why[1] |
| ok = 0 |
| |
| if ok: |
| a_type = stat.S_IFMT(a_stat.st_mode) |
| b_type = stat.S_IFMT(b_stat.st_mode) |
| if a_type != b_type: |
| self.common_funny.append(x) |
| elif stat.S_ISDIR(a_type): |
| self.common_dirs.append(x) |
| elif stat.S_ISREG(a_type): |
| self.common_files.append(x) |
| else: |
| self.common_funny.append(x) |
| else: |
| self.common_funny.append(x) |
| |
| def phase3(self): # Find out differences between common files |
| xx = cmpfiles(self.left, self.right, self.common_files) |
| self.same_files, self.diff_files, self.funny_files = xx |
| |
| def phase4(self): # Find out differences between common subdirectories |
| # A new dircmp object is created for each common subdirectory, |
| # these are stored in a dictionary indexed by filename. |
| # The hide and ignore properties are inherited from the parent |
| self.subdirs = {} |
| for x in self.common_dirs: |
| a_x = os.path.join(self.left, x) |
| b_x = os.path.join(self.right, x) |
| self.subdirs[x] = dircmp(a_x, b_x, self.ignore, self.hide) |
| |
| def phase4_closure(self): # Recursively call phase4() on subdirectories |
| self.phase4() |
| for sd in self.subdirs.itervalues(): |
| sd.phase4_closure() |
| |
| def report(self): # Print a report on the differences between a and b |
| # Output format is purposely lousy |
| print 'diff', self.left, self.right |
| if self.left_only: |
| self.left_only.sort() |
| print 'Only in', self.left, ':', self.left_only |
| if self.right_only: |
| self.right_only.sort() |
| print 'Only in', self.right, ':', self.right_only |
| if self.same_files: |
| self.same_files.sort() |
| print 'Identical files :', self.same_files |
| if self.diff_files: |
| self.diff_files.sort() |
| print 'Differing files :', self.diff_files |
| if self.funny_files: |
| self.funny_files.sort() |
| print 'Trouble with common files :', self.funny_files |
| if self.common_dirs: |
| self.common_dirs.sort() |
| print 'Common subdirectories :', self.common_dirs |
| if self.common_funny: |
| self.common_funny.sort() |
| print 'Common funny cases :', self.common_funny |
| |
| def report_partial_closure(self): # Print reports on self and on subdirs |
| self.report() |
| for sd in self.subdirs.itervalues(): |
| print |
| sd.report() |
| |
| def report_full_closure(self): # Report on self and subdirs recursively |
| self.report() |
| for sd in self.subdirs.itervalues(): |
| print |
| sd.report_full_closure() |
| |
| methodmap = dict(subdirs=phase4, |
| same_files=phase3, diff_files=phase3, funny_files=phase3, |
| common_dirs = phase2, common_files=phase2, common_funny=phase2, |
| common=phase1, left_only=phase1, right_only=phase1, |
| left_list=phase0, right_list=phase0) |
| |
| def __getattr__(self, attr): |
| if attr not in self.methodmap: |
| raise AttributeError, attr |
| self.methodmap[attr](self) |
| return getattr(self, attr) |
| |
| def cmpfiles(a, b, common, shallow=1): |
| """Compare common files in two directories. |
| |
| a, b -- directory names |
| common -- list of file names found in both directories |
| shallow -- if true, do comparison based solely on stat() information |
| |
| Returns a tuple of three lists: |
| files that compare equal |
| files that are different |
| filenames that aren't regular files. |
| |
| """ |
| res = ([], [], []) |
| for x in common: |
| ax = os.path.join(a, x) |
| bx = os.path.join(b, x) |
| res[_cmp(ax, bx, shallow)].append(x) |
| return res |
| |
| |
| # Compare two files. |
| # Return: |
| # 0 for equal |
| # 1 for different |
| # 2 for funny cases (can't stat, etc.) |
| # |
| def _cmp(a, b, sh, abs=abs, cmp=cmp): |
| try: |
| return not abs(cmp(a, b, sh)) |
| except (os.error, IOError): |
| return 2 |
| |
| |
| # Return a copy with items that occur in skip removed. |
| # |
| def _filter(flist, skip): |
| return list(ifilterfalse(skip.__contains__, flist)) |
| |
| |
| # Demonstration and testing. |
| # |
| def demo(): |
| import sys |
| import getopt |
| options, args = getopt.getopt(sys.argv[1:], 'r') |
| if len(args) != 2: |
| raise getopt.GetoptError('need exactly two args', None) |
| dd = dircmp(args[0], args[1]) |
| if ('-r', '') in options: |
| dd.report_full_closure() |
| else: |
| dd.report() |
| |
| if __name__ == '__main__': |
| demo() |
