1  """ Command line interface to difflib.py providing diffs in four formats:
       2  
       3  * ndiff:    lists every line and highlights interline changes.
       4  * context:  highlights clusters of changes in a before/after format.
       5  * unified:  highlights clusters of changes in an inline format.
       6  * html:     generates side by side comparison with change highlights.
       7  
       8  """
       9  
      10  import sys, os, difflib, argparse
      11  from datetime import datetime, timezone
      12  
      13  def file_mtime(path):
      14      t = datetime.fromtimestamp(os.stat(path).st_mtime,
      15                                 timezone.utc)
      16      return t.astimezone().isoformat()
      17  
      18  def main():
      19  
      20      parser = argparse.ArgumentParser()
      21      parser.add_argument('-c', action='store_true', default=False,
      22                          help='Produce a context format diff (default)')
      23      parser.add_argument('-u', action='store_true', default=False,
      24                          help='Produce a unified format diff')
      25      parser.add_argument('-m', action='store_true', default=False,
      26                          help='Produce HTML side by side diff '
      27                               '(can use -c and -l in conjunction)')
      28      parser.add_argument('-n', action='store_true', default=False,
      29                          help='Produce a ndiff format diff')
      30      parser.add_argument('-l', '--lines', type=int, default=3,
      31                          help='Set number of context lines (default 3)')
      32      parser.add_argument('fromfile')
      33      parser.add_argument('tofile')
      34      options = parser.parse_args()
      35  
      36      n = options.lines
      37      fromfile = options.fromfile
      38      tofile = options.tofile
      39  
      40      fromdate = file_mtime(fromfile)
      41      todate = file_mtime(tofile)
      42      with open(fromfile) as ff:
      43          fromlines = ff.readlines()
      44      with open(tofile) as tf:
      45          tolines = tf.readlines()
      46  
      47      if options.u:
      48          diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
      49      elif options.n:
      50          diff = difflib.ndiff(fromlines, tolines)
      51      elif options.m:
      52          diff = difflib.HtmlDiff().make_file(fromlines,tolines,fromfile,tofile,context=options.c,numlines=n)
      53      else:
      54          diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
      55  
      56      sys.stdout.writelines(diff)
      57  
      58  if __name__ == '__main__':
      59      main()