diff.py revision a33d17758974e0d150cc07a22c0c60b1485d0ab4 
1""" Command line interface to difflib.py providing diffs in three 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
7"""
8
9import sys, os, time, difflib, optparse
10
11usage = "usage: %prog [options] fromfile tofile"
12parser = optparse.OptionParser(usage)
13parser.add_option("-c", action="store_true", default=False, help='Produce a context format diff (default)')
14parser.add_option("-u", action="store_true", default=False, help='Produce a unified format diff')
15parser.add_option("-n", action="store_true", default=False, help='Produce a ndiff format diff')
16parser.add_option("-l", "--lines", type="int", default=3, help='Set number of context lines (default 3)')
17(options, args) = parser.parse_args()
18
19if len(args) == 0:
20    parser.print_help()
21    sys.exit(1)
22if len(args) != 2:
23    parser.error("need to specify both a fromfile and tofile")
24
25n = options.lines
26fromfile, tofile = args
27
28fromdate = time.ctime(os.stat(fromfile).st_mtime)
29todate = time.ctime(os.stat(tofile).st_mtime)
30fromlines = open(fromfile).readlines()
31tolines = open(tofile).readlines()
32
33if options.u:
34    diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
35elif options.n:
36    diff = difflib.ndiff(fromlines, tolines)
37else:
38    diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
39
40sys.stdout.writelines(diff)
41
42