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
10import sys, os, time, difflib, optparse
11
12def main():
13
14    usage = "usage: %prog [options] fromfile tofile"
15    parser = optparse.OptionParser(usage)
16    parser.add_option("-c", action="store_true", default=False, help='Produce a context format diff (default)')
17    parser.add_option("-u", action="store_true", default=False, help='Produce a unified format diff')
18    parser.add_option("-m", action="store_true", default=False, help='Produce HTML side by side diff (can use -c and -l in conjunction)')
19    parser.add_option("-n", action="store_true", default=False, help='Produce a ndiff format diff')
20    parser.add_option("-l", "--lines", type="int", default=3, help='Set number of context lines (default 3)')
21    (options, args) = parser.parse_args()
22
23    if len(args) == 0:
24        parser.print_help()
25        sys.exit(1)
26    if len(args) != 2:
27        parser.error("need to specify both a fromfile and tofile")
28
29    n = options.lines
30    fromfile, tofile = args
31
32    fromdate = time.ctime(os.stat(fromfile).st_mtime)
33    todate = time.ctime(os.stat(tofile).st_mtime)
34    fromlines = open(fromfile, 'U').readlines()
35    tolines = open(tofile, 'U').readlines()
36
37    if options.u:
38        diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
39    elif options.n:
40        diff = difflib.ndiff(fromlines, tolines)
41    elif options.m:
42        diff = difflib.HtmlDiff().make_file(fromlines,tolines,fromfile,tofile,context=options.c,numlines=n)
43    else:
44        diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
45
46    sys.stdout.writelines(diff)
47
48if __name__ == '__main__':
49    main()
50