ndiff.py

#! /usr/bin/env python

# Module ndiff version 1.7.0
# Released to the public domain 08-Dec-2000,
# by Tim Peters (tim.one@home.com).

# Provided as-is; use at your own risk; no warranty; no promises; enjoy!

# ndiff.py is now simply a front-end to the difflib.ndiff() function.
# Originally, it contained the difflib.SequenceMatcher class as well.
# This completes the raiding of reusable code from this formerly
# self-contained script.

"""ndiff [-q] file1 file2
 or
ndiff (-r1 | -r2) < ndiff_output > file1_or_file2

Print a human-friendly file difference report to stdout. Both inter-
and intra-line differences are noted. In the second form, recreate file1
(-r1) or file2 (-r2) on stdout, from an ndiff report on stdin.

In the first form, if -q ("quiet") is not specified, the first two lines
of output are

-: file1
+: file2

Each remaining line begins with a two-letter code:

 "- " line unique to file1
 "+ " line unique to file2
 " " line common to both files
 "? " line not present in either input file

Lines beginning with "? " attempt to guide the eye to intraline
differences, and were not present in either input file. These lines can be
confusing if the source files contain tab characters.

The first file can be recovered by retaining only lines that begin with
" " or "- ", and deleting those 2-character prefixes; use ndiff with -r1.

The second file can be recovered similarly, but by retaining only " " and
"+ " lines; use ndiff with -r2; or, on Unix, the second file can be
recovered by piping the output through

 sed -n '/^[+ ] /s/^..//p'
"""

__version__=1, 7, 0

importdifflib, sys

deffail(msg):
out=sys.stderr.write
out(msg+"\n\n")
out(__doc__)
return0

# open a file & return the file object; gripe and return 0 if it
# couldn't be opened
deffopen(fname):
try:
returnopen(fname, 'U')
exceptIOError, detail:
returnfail("couldn't open "+fname+": "+str(detail))

# open two files & spray the diff to stdout; return false iff a problem
deffcompare(f1name, f2name):
f1=fopen(f1name)
f2=fopen(f2name)
ifnotf1ornotf2:
return0

a=f1.readlines(); f1.close()
b=f2.readlines(); f2.close()
forlineindifflib.ndiff(a, b):
printline,

return1

# crack args (sys.argv[1:] is normal) & compare;
# return false iff a problem

defmain(args):
importgetopt
try:
opts, args=getopt.getopt(args, "qr:")
exceptgetopt.error, detail:
returnfail(str(detail))
noisy=1
qseen=rseen=0
foropt, valinopts:
ifopt=="-q":
qseen=1
noisy=0
elifopt=="-r":
rseen=1
whichfile=val
ifqseenandrseen:
returnfail("can't specify both -q and -r")
ifrseen:
ifargs:
returnfail("no args allowed with -r option")
ifwhichfilein ("1", "2"):
restore(whichfile)
return1
returnfail("-r value must be 1 or 2")
iflen(args) !=2:
returnfail("need 2 filename args")
f1name, f2name=args
ifnoisy:
print'-:', f1name
print'+:', f2name
returnfcompare(f1name, f2name)

# read ndiff output from stdin, and print file1 (which=='1') or
# file2 (which=='2') to stdout

defrestore(which):
restored=difflib.restore(sys.stdin.readlines(), which)
sys.stdout.writelines(restored)

if__name__=='__main__':
args=sys.argv[1:]
if"-profile"inargs:
importprofile, pstats
args.remove("-profile")
statf="ndiff.pro"
profile.run("main(args)", statf)
stats=pstats.Stats(statf)
stats.strip_dirs().sort_stats('time').print_stats()
else:
main(args)