| #! /usr/bin/env python |
| |
| # Module ndiff version 1.6.0 |
| # Released to the public domain 08-Dec-2000, |
| # by Tim Peters (tim.one@home.com). |
| |
| # Provided as-is; use at your own risk; no warranty; no promises; enjoy! |
| |
| """ndiff [-q] file1 file2 |
| or |
| ndiff (-r1 | -r2) < ndiff_output > file1_or_file2 |
| |
| Print a human-friendly file difference report to stdout. Both inter- |
| and intra-line differences are noted. In the second form, recreate file1 |
| (-r1) or file2 (-r2) on stdout, from an ndiff report on stdin. |
| |
| In the first form, if -q ("quiet") is not specified, the first two lines |
| of output are |
| |
| -: file1 |
| +: file2 |
| |
| Each remaining line begins with a two-letter code: |
| |
| "- " line unique to file1 |
| "+ " line unique to file2 |
| " " line common to both files |
| "? " line not present in either input file |
| |
| Lines beginning with "? " attempt to guide the eye to intraline |
| differences, and were not present in either input file. These lines can be |
| confusing if the source files contain tab characters. |
| |
| The first file can be recovered by retaining only lines that begin with |
| " " or "- ", and deleting those 2-character prefixes; use ndiff with -r1. |
| |
| The second file can be recovered similarly, but by retaining only " " and |
| "+ " lines; use ndiff with -r2; or, on Unix, the second file can be |
| recovered by piping the output through |
| |
| sed -n '/^[+ ] /s/^..//p' |
| |
| See module comments for details and programmatic interface. |
| """ |
| |
| __version__ = 1, 5, 0 |
| |
| # SequenceMatcher tries to compute a "human-friendly diff" between |
| # two sequences (chiefly picturing a file as a sequence of lines, |
| # and a line as a sequence of characters, here). Unlike e.g. UNIX(tm) |
| # diff, the fundamental notion is the longest *contiguous* & junk-free |
| # matching subsequence. That's what catches peoples' eyes. The |
| # Windows(tm) windiff has another interesting notion, pairing up elements |
| # that appear uniquely in each sequence. That, and the method here, |
| # appear to yield more intuitive difference reports than does diff. This |
| # method appears to be the least vulnerable to synching up on blocks |
| # of "junk lines", though (like blank lines in ordinary text files, |
| # or maybe "<P>" lines in HTML files). That may be because this is |
| # the only method of the 3 that has a *concept* of "junk" <wink>. |
| # |
| # Note that ndiff makes no claim to produce a *minimal* diff. To the |
| # contrary, minimal diffs are often counter-intuitive, because they |
| # synch up anywhere possible, sometimes accidental matches 100 pages |
| # apart. Restricting synch points to contiguous matches preserves some |
| # notion of locality, at the occasional cost of producing a longer diff. |
| # |
| # With respect to junk, an earlier version of ndiff simply refused to |
| # *start* a match with a junk element. The result was cases like this: |
| # before: private Thread currentThread; |
| # after: private volatile Thread currentThread; |
| # If you consider whitespace to be junk, the longest contiguous match |
| # not starting with junk is "e Thread currentThread". So ndiff reported |
| # that "e volatil" was inserted between the 't' and the 'e' in "private". |
| # While an accurate view, to people that's absurd. The current version |
| # looks for matching blocks that are entirely junk-free, then extends the |
| # longest one of those as far as possible but only with matching junk. |
| # So now "currentThread" is matched, then extended to suck up the |
| # preceding blank; then "private" is matched, and extended to suck up the |
| # following blank; then "Thread" is matched; and finally ndiff reports |
| # that "volatile " was inserted before "Thread". The only quibble |
| # remaining is that perhaps it was really the case that " volatile" |
| # was inserted after "private". I can live with that <wink>. |
| # |
| # NOTE on junk: the module-level names |
| # IS_LINE_JUNK |
| # IS_CHARACTER_JUNK |
| # can be set to any functions you like. The first one should accept |
| # a single string argument, and return true iff the string is junk. |
| # The default is whether the regexp r"\s*#?\s*$" matches (i.e., a |
| # line without visible characters, except for at most one splat). |
| # The second should accept a string of length 1 etc. The default is |
| # whether the character is a blank or tab (note: bad idea to include |
| # newline in this!). |
| # |
| # After setting those, you can call fcompare(f1name, f2name) with the |
| # names of the files you want to compare. The difference report |
| # is sent to stdout. Or you can call main(args), passing what would |
| # have been in sys.argv[1:] had the cmd-line form been used. |
| |
| from difflib import SequenceMatcher |
| |
| import string |
| TRACE = 0 |
| |
| # define what "junk" means |
| import re |
| |
| def IS_LINE_JUNK(line, pat=re.compile(r"\s*#?\s*$").match): |
| return pat(line) is not None |
| |
| def IS_CHARACTER_JUNK(ch, ws=" \t"): |
| return ch in ws |
| |
| del re |
| |
| # meant for dumping lines |
| def dump(tag, x, lo, hi): |
| for i in xrange(lo, hi): |
| print tag, x[i], |
| |
| def plain_replace(a, alo, ahi, b, blo, bhi): |
| assert alo < ahi and blo < bhi |
| # dump the shorter block first -- reduces the burden on short-term |
| # memory if the blocks are of very different sizes |
| if bhi - blo < ahi - alo: |
| dump('+', b, blo, bhi) |
| dump('-', a, alo, ahi) |
| else: |
| dump('-', a, alo, ahi) |
| dump('+', b, blo, bhi) |
| |
| # When replacing one block of lines with another, this guy searches |
| # the blocks for *similar* lines; the best-matching pair (if any) is |
| # used as a synch point, and intraline difference marking is done on |
| # the similar pair. Lots of work, but often worth it. |
| |
| def fancy_replace(a, alo, ahi, b, blo, bhi): |
| if TRACE: |
| print '*** fancy_replace', alo, ahi, blo, bhi |
| dump('>', a, alo, ahi) |
| dump('<', b, blo, bhi) |
| |
| # don't synch up unless the lines have a similarity score of at |
| # least cutoff; best_ratio tracks the best score seen so far |
| best_ratio, cutoff = 0.74, 0.75 |
| cruncher = SequenceMatcher(IS_CHARACTER_JUNK) |
| eqi, eqj = None, None # 1st indices of equal lines (if any) |
| |
| # search for the pair that matches best without being identical |
| # (identical lines must be junk lines, & we don't want to synch up |
| # on junk -- unless we have to) |
| for j in xrange(blo, bhi): |
| bj = b[j] |
| cruncher.set_seq2(bj) |
| for i in xrange(alo, ahi): |
| ai = a[i] |
| if ai == bj: |
| if eqi is None: |
| eqi, eqj = i, j |
| continue |
| cruncher.set_seq1(ai) |
| # computing similarity is expensive, so use the quick |
| # upper bounds first -- have seen this speed up messy |
| # compares by a factor of 3. |
| # note that ratio() is only expensive to compute the first |
| # time it's called on a sequence pair; the expensive part |
| # of the computation is cached by cruncher |
| if cruncher.real_quick_ratio() > best_ratio and \ |
| cruncher.quick_ratio() > best_ratio and \ |
| cruncher.ratio() > best_ratio: |
| best_ratio, best_i, best_j = cruncher.ratio(), i, j |
| if best_ratio < cutoff: |
| # no non-identical "pretty close" pair |
| if eqi is None: |
| # no identical pair either -- treat it as a straight replace |
| plain_replace(a, alo, ahi, b, blo, bhi) |
| return |
| # no close pair, but an identical pair -- synch up on that |
| best_i, best_j, best_ratio = eqi, eqj, 1.0 |
| else: |
| # there's a close pair, so forget the identical pair (if any) |
| eqi = None |
| |
| # a[best_i] very similar to b[best_j]; eqi is None iff they're not |
| # identical |
| if TRACE: |
| print '*** best_ratio', best_ratio, best_i, best_j |
| dump('>', a, best_i, best_i+1) |
| dump('<', b, best_j, best_j+1) |
| |
| # pump out diffs from before the synch point |
| fancy_helper(a, alo, best_i, b, blo, best_j) |
| |
| # do intraline marking on the synch pair |
| aelt, belt = a[best_i], b[best_j] |
| if eqi is None: |
| # pump out a '-', '?', '+', '?' quad for the synched lines |
| atags = btags = "" |
| cruncher.set_seqs(aelt, belt) |
| for tag, ai1, ai2, bj1, bj2 in cruncher.get_opcodes(): |
| la, lb = ai2 - ai1, bj2 - bj1 |
| if tag == 'replace': |
| atags += '^' * la |
| btags += '^' * lb |
| elif tag == 'delete': |
| atags += '-' * la |
| elif tag == 'insert': |
| btags += '+' * lb |
| elif tag == 'equal': |
| atags += ' ' * la |
| btags += ' ' * lb |
| else: |
| raise ValueError, 'unknown tag ' + `tag` |
| printq(aelt, belt, atags, btags) |
| else: |
| # the synch pair is identical |
| print ' ', aelt, |
| |
| # pump out diffs from after the synch point |
| fancy_helper(a, best_i+1, ahi, b, best_j+1, bhi) |
| |
| def fancy_helper(a, alo, ahi, b, blo, bhi): |
| if alo < ahi: |
| if blo < bhi: |
| fancy_replace(a, alo, ahi, b, blo, bhi) |
| else: |
| dump('-', a, alo, ahi) |
| elif blo < bhi: |
| dump('+', b, blo, bhi) |
| |
| # Crap to deal with leading tabs in "?" output. Can hurt, but will |
| # probably help most of the time. |
| |
| def printq(aline, bline, atags, btags): |
| common = min(count_leading(aline, "\t"), |
| count_leading(bline, "\t")) |
| common = min(common, count_leading(atags[:common], " ")) |
| print "-", aline, |
| if count_leading(atags, " ") < len(atags): |
| print "?", "\t" * common + atags[common:] |
| print "+", bline, |
| if count_leading(btags, " ") < len(btags): |
| print "?", "\t" * common + btags[common:] |
| |
| def count_leading(line, ch): |
| i, n = 0, len(line) |
| while i < n and line[i] == ch: |
| i += 1 |
| return i |
| |
| def fail(msg): |
| import sys |
| out = sys.stderr.write |
| out(msg + "\n\n") |
| out(__doc__) |
| return 0 |
| |
| # open a file & return the file object; gripe and return 0 if it |
| # couldn't be opened |
| def fopen(fname): |
| try: |
| return open(fname, 'r') |
| except IOError, detail: |
| return fail("couldn't open " + fname + ": " + str(detail)) |
| |
| # open two files & spray the diff to stdout; return false iff a problem |
| def fcompare(f1name, f2name): |
| f1 = fopen(f1name) |
| f2 = fopen(f2name) |
| if not f1 or not f2: |
| return 0 |
| |
| a = f1.readlines(); f1.close() |
| b = f2.readlines(); f2.close() |
| |
| cruncher = SequenceMatcher(IS_LINE_JUNK, a, b) |
| for tag, alo, ahi, blo, bhi in cruncher.get_opcodes(): |
| if tag == 'replace': |
| fancy_replace(a, alo, ahi, b, blo, bhi) |
| elif tag == 'delete': |
| dump('-', a, alo, ahi) |
| elif tag == 'insert': |
| dump('+', b, blo, bhi) |
| elif tag == 'equal': |
| dump(' ', a, alo, ahi) |
| else: |
| raise ValueError, 'unknown tag ' + `tag` |
| |
| return 1 |
| |
| # crack args (sys.argv[1:] is normal) & compare; |
| # return false iff a problem |
| |
| def main(args): |
| import getopt |
| try: |
| opts, args = getopt.getopt(args, "qr:") |
| except getopt.error, detail: |
| return fail(str(detail)) |
| noisy = 1 |
| qseen = rseen = 0 |
| for opt, val in opts: |
| if opt == "-q": |
| qseen = 1 |
| noisy = 0 |
| elif opt == "-r": |
| rseen = 1 |
| whichfile = val |
| if qseen and rseen: |
| return fail("can't specify both -q and -r") |
| if rseen: |
| if args: |
| return fail("no args allowed with -r option") |
| if whichfile in "12": |
| restore(whichfile) |
| return 1 |
| return fail("-r value must be 1 or 2") |
| if len(args) != 2: |
| return fail("need 2 filename args") |
| f1name, f2name = args |
| if noisy: |
| print '-:', f1name |
| print '+:', f2name |
| return fcompare(f1name, f2name) |
| |
| def restore(which): |
| import sys |
| tag = {"1": "- ", "2": "+ "}[which] |
| prefixes = (" ", tag) |
| for line in sys.stdin.readlines(): |
| if line[:2] in prefixes: |
| print line[2:], |
| |
| if __name__ == '__main__': |
| import sys |
| args = sys.argv[1:] |
| if "-profile" in args: |
| import profile, pstats |
| args.remove("-profile") |
| statf = "ndiff.pro" |
| profile.run("main(args)", statf) |
| stats = pstats.Stats(statf) |
| stats.strip_dirs().sort_stats('time').print_stats() |
| else: |
| main(args) |