1  #!/usr/bin/env python3
       2  """ Command line interface to difflib.py providing diffs in four formats:
       3  
       4  * ndiff:    lists every line and highlights interline changes.
       5  * context:  highlights clusters of changes in a before/after format.
       6  * unified:  highlights clusters of changes in an inline format.
       7  * html:     generates side by side comparison with change highlights.
       8  
       9  """
      10  
      11  import sys, os, difflib, argparse
      12  from datetime import datetime, timezone
      13  
      14  def file_mtime(path):
      15      t = datetime.fromtimestamp(os.stat(path).st_mtime,
      16                                 timezone.utc)
      17      return t.astimezone().isoformat()
      18  
      19  def main():
      20  
      21      parser = argparse.ArgumentParser()
      22      parser.add_argument('-c', action='store_true', default=False,
      23                          help='Produce a context format diff (default)')
      24      parser.add_argument('-u', action='store_true', default=False,
      25                          help='Produce a unified format diff')
      26      parser.add_argument('-m', action='store_true', default=False,
      27                          help='Produce HTML side by side diff '
      28                               '(can use -c and -l in conjunction)')
      29      parser.add_argument('-n', action='store_true', default=False,
      30                          help='Produce a ndiff format diff')
      31      parser.add_argument('-l', '--lines', type=int, default=3,
      32                          help='Set number of context lines (default 3)')
      33      parser.add_argument('fromfile')
      34      parser.add_argument('tofile')
      35      options = parser.parse_args()
      36  
      37      n = options.lines
      38      fromfile = options.fromfile
      39      tofile = options.tofile
      40  
      41      fromdate = file_mtime(fromfile)
      42      todate = file_mtime(tofile)
      43      with open(fromfile) as ff:
      44          fromlines = ff.readlines()
      45      with open(tofile) as tf:
      46          tolines = tf.readlines()
      47  
      48      if options.u:
      49          diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
      50      elif options.n:
      51          diff = difflib.ndiff(fromlines, tolines)
      52      elif options.m:
      53          diff = difflib.HtmlDiff().make_file(fromlines,tolines,fromfile,tofile,context=options.c,numlines=n)
      54      else:
      55          diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
      56  
      57      sys.stdout.writelines(diff)
      58  
      59  if __name__ == '__main__':
      60      main()