blob: 32c251bce9120b77d65278dc3420c4de26753113 [file] [log] [blame]
"""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
import difflib, sys
def fail(msg):
out = sys.stderr.write
out(msg + "\n\n")
out(__doc__)
return 0
# open a file & return the file object; gripe and return 0 if it
# couldn't be opened
def fopen(fname):
try:
return open(fname)
except IOError as detail:
return fail("couldn't open " + fname + ": " + str(detail))
# open two files & spray the diff to stdout; return false iff a problem
def fcompare(f1name, f2name):
f1 = fopen(f1name)
f2 = fopen(f2name)
if not f1 or not f2:
return 0
a = f1.readlines(); f1.close()
b = f2.readlines(); f2.close()
for line in difflib.ndiff(a, b):
print(line, end=' ')
return 1
# crack args (sys.argv[1:] is normal) & compare;
# return false iff a problem
def main(args):
import getopt
try:
opts, args = getopt.getopt(args, "qr:")
except getopt.error as detail:
return fail(str(detail))
noisy = 1
qseen = rseen = 0
for opt, val in opts:
if opt == "-q":
qseen = 1
noisy = 0
elif opt == "-r":
rseen = 1
whichfile = val
if qseen and rseen:
return fail("can't specify both -q and -r")
if rseen:
if args:
return fail("no args allowed with -r option")
if whichfile in ("1", "2"):
restore(whichfile)
return 1
return fail("-r value must be 1 or 2")
if len(args) != 2:
return fail("need 2 filename args")
f1name, f2name = args
if noisy:
print('-:', f1name)
print('+:', f2name)
return fcompare(f1name, f2name)
# read ndiff output from stdin, and print file1 (which=='1') or
# file2 (which=='2') to stdout
def restore(which):
restored = difflib.restore(sys.stdin.readlines(), which)
sys.stdout.writelines(restored)
if __name__ == '__main__':
main(sys.argv[1:])