1#!/usr/bin/env python
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
11import sys, os, time, difflib, optparse
12
13def main():
14
15    usage = "usage: %prog [options] fromfile tofile"
16    parser = optparse.OptionParser(usage)
17    parser.add_option("-c", action="store_true", default=False, help='Produce a context format diff (default)')
18    parser.add_option("-u", action="store_true", default=False, help='Produce a unified format diff')
19    parser.add_option("-m", action="store_true", default=False, help='Produce HTML side by side diff (can use -c and -l in conjunction)')
20    parser.add_option("-n", action="store_true", default=False, help='Produce a ndiff format diff')
21    parser.add_option("-l", "--lines", type="int", default=3, help='Set number of context lines (default 3)')
22    (options, args) = parser.parse_args()
23
24    if len(args) == 0:
25        parser.print_help()
26        sys.exit(1)
27    if len(args) != 2:
28        parser.error("need to specify both a fromfile and tofile")
29
30    n = options.lines
31    fromfile, tofile = args
32
33    fromdate = time.ctime(os.stat(fromfile).st_mtime)
34    todate = time.ctime(os.stat(tofile).st_mtime)
35    with open(fromfile, 'U') as f:
36        fromlines = f.readlines()
37    with open(tofile, 'U') as f:
38        tolines = f.readlines()
39
40    if options.u:
41        diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
42    elif options.n:
43        diff = difflib.ndiff(fromlines, tolines)
44    elif options.m:
45        diff = difflib.HtmlDiff().make_file(fromlines,tolines,fromfile,tofile,context=options.c,numlines=n)
46    else:
47        diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
48
49    sys.stdout.writelines(diff)
50
51if __name__ == '__main__':
52    main()
53