Intelligent diff between text files (Tim Peters)，diffpeters,#! /usr/bin/

Intelligent diff between text files (Tim Peters)，diffpeters,#! /usr/bin/

#! /usr/bin/env python# Module ndiff version 1.7.0# 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.py is now simply a front-end to the difflib.ndiff() function.# Originally, it contained the difflib.SequenceMatcher class as well.# This completes the raiding of reusable code from this formerly# self-contained script.'''ndiff [-q] file1 file2    orndiff (-r1 | -r2) < ndiff_output > file1_or_file2Print 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 linesof output are-: file1+: file2Each 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 fileLines beginning with '? ' attempt to guide the eye to intralinedifferences, and were not present in either input file.  These lines can beconfusing 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 berecovered by piping the output through    sed -n '/^[+ ] /s/^..//p''''__version__ = 1, 7, 0import difflib, sysdef fail(msg):    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 openeddef fopen(fname):    try:        return open(fname, 'U')    except IOError, detail:        return fail('couldn't open ' + fname + ': ' + str(detail))# open two files & spray the diff to stdout; return false iff a problemdef 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()    for line in difflib.ndiff(a, b):        print line,    return 1# crack args (sys.argv[1:] is normal) & compare;# return false iff a problemdef 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 ('1', '2'):            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)# read ndiff output from stdin, and print file1 (which=='1') or# file2 (which=='2') to stdoutdef restore(which):    restored = difflib.restore(sys.stdin.readlines(), which)    sys.stdout.writelines(restored)if __name__ == '__main__':    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)