CasperSecurity
#! /usr/bin/python3
# -*- coding: utf-8 -*-
import sys
import os.path
import json
import jsonpatch
import tempfile
import argparse
parser = argparse.ArgumentParser(
description='Apply a JSON patch on a JSON file')
parser.add_argument('ORIGINAL', type=argparse.FileType('r'),
help='Original file')
parser.add_argument('PATCH', type=argparse.FileType('r'),
nargs='?', default=sys.stdin,
help='Patch file (read from stdin if omitted)')
parser.add_argument('--indent', type=int, default=None,
help='Indent output by n spaces')
parser.add_argument('-b', '--backup', action='store_true',
help='Back up ORIGINAL if modifying in-place')
parser.add_argument('-i', '--in-place', action='store_true',
help='Modify ORIGINAL in-place instead of to stdout')
parser.add_argument('-v', '--version', action='version',
version='%(prog)s ' + jsonpatch.__version__)
parser.add_argument('-u', '--preserve-unicode', action='store_true',
help='Output Unicode character as-is without using Code Point')
def main():
try:
patch_files()
except KeyboardInterrupt:
sys.exit(1)
def patch_files():
""" Diffs two JSON files and prints a patch """
args = parser.parse_args()
doc = json.load(args.ORIGINAL)
patch = json.load(args.PATCH)
result = jsonpatch.apply_patch(doc, patch)
if args.in_place:
dirname = os.path.abspath(os.path.dirname(args.ORIGINAL.name))
try:
# Attempt to replace the file atomically. We do this by
# creating a temporary file in the same directory as the
# original file so we can atomically move the new file over
# the original later. (This is done in the same directory
# because atomic renames do not work across mount points.)
fd, pathname = tempfile.mkstemp(dir=dirname)
fp = os.fdopen(fd, 'w')
atomic = True
except OSError:
# We failed to create the temporary file for an atomic
# replace, so fall back to non-atomic mode by backing up
# the original (if desired) and writing a new file.
if args.backup:
os.rename(args.ORIGINAL.name, args.ORIGINAL.name + '.orig')
fp = open(args.ORIGINAL.name, 'w')
atomic = False
else:
# Since we're not replacing the original file in-place, write
# the modified JSON to stdout instead.
fp = sys.stdout
# By this point we have some sort of file object we can write the
# modified JSON to.
json.dump(result, fp, indent=args.indent, ensure_ascii=not(args.preserve_unicode))
fp.write('\n')
if args.in_place:
# Close the new file. If we aren't replacing atomically, this
# is our last step, since everything else is already in place.
fp.close()
if atomic:
try:
# Complete the atomic replace by linking the original
# to a backup (if desired), fixing up the permissions
# on the temporary file, and moving it into place.
if args.backup:
os.link(args.ORIGINAL.name, args.ORIGINAL.name + '.orig')
os.chmod(pathname, os.stat(args.ORIGINAL.name).st_mode)
os.rename(pathname, args.ORIGINAL.name)
except OSError:
# In the event we could not actually do the atomic
# replace, unlink the original to move it out of the
# way and finally move the temporary file into place.
os.unlink(args.ORIGINAL.name)
os.rename(pathname, args.ORIGINAL.name)
if __name__ == "__main__":
main()