User:Tardis/regdiff.py: Difference between revisions

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<sourcesyntaxhighlight lang="python">

#!/usr/bin/env python

#regdiff.py

#Created November 9 2008

#Updated November 910 2008

#Version 0.3.1

#This program is free software; you can redistribute it and/or modify it under

#the terms of the GNU General Public License version 2, the GNU Free

#Documentation License version 1.2, or (atwith yourno option)Invariant any laterSections, versionwith ofno

#Front-Cover Texts, and with no Back-Cover Texts), or (at your option) any

#either license.

#later version of either license. It is distributed in the hope that it will

#be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of

#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

#Public License for more details.

#Description:

#Compares two Windows registry (.REG) files and produces a third such that

#applying it transforms a registry represented by the first into a registry

#represented by the second. (ThatUsually is,you itshould deletesredirect allthe keysoutput andto valuesa presentfile.

#in the first but not in the second!)

#Set displayProgress to a positive value n to report with a # every n lines.

#BUGS:

#Warnings:

#The output deletes all keys and values present in the first but not in the

#second! Therefore, this should be run only on exports of complete subtrees.

#The input must be sorted (values sorted within each key); I believe that

#Regedit's export does this, and will also guarantee complete subtrees.

#It's probably wise to double check any key removals in the output: look for

#lines beginning with the two characters "[-". Modern .REG files use UTF-16,

#so some editors and tools (like grep) may have trouble with them. Using

#"grep '^.\[.-' out.reg" should work to at least detect removals.

#You can disable deletions of keys or values entirely by setting the

#appropriate variables (allow*Delete). If keys cannot be deleted but values

#can, each value named in the old file under a key that would be deleted will

#be deleted. (This is not as dangerous because reapplying the old file will

#restore them.)

#History:

#Version 0.1, November 9 2008:

# - initial release

#Version 0.2, November 9 2008:

# - use CRLF newlines

# - support deletion disabling

# - detect misorderings

#Version 0.3, November 9 2008:

# - make allowKeyDelete apply to the last keys to delete

# - verify continuous progress

# - support displaying progress

#Version 0.3.1, November 10 2008:

# - use case-insensitive and subkey-aware comparisons for ordering

#Bugs:

#Assumes that no key contains assignments to @ and to "" -- I think the latter

#is invalid anyway. Also changes any literal \r\n in strings to \n.

#I don't know whether .REG files are really UTF-16 or UCS-2.

#I'm not sure that the last blank line is really necessary; a trailing CRLF

#may be sufficient.

import sys,codecs

def keycompare(a,b):

"""Return an integer indicating the ordering of keys a and b."""

return cmp(a.lower().split('\\'),b.lower().split('\\'))

class line(object):

def __init__(self,s,k=None):

"""Parse s and make a line object.

Inherit key from line k unless we are a key or it is omitted or None.

Use k to detect misordered input if it is not None.

Names are not unescaped, but escaping is considered in their extent."""

self.old=False

Line 38 ⟶ 86:

elif self.iskey:

self.delete=s[1]=='-'

self.lastkey=self.name=s[1+self.delete:-23] # ends in "]\r\n"

if k is not None and k.lastkey is not None and\

keycompare(self.lastkey,k.lastkey)<0:

raise ValueError,"key %r precedes %r in input"%\

(k.lastkey,self.lastkey)

else:

if s[0]=='"':

Line 48 ⟶ 100:

elif c=='"': break

else: raise IOError,"unterminated name in "+repr(s)

elif s[0]=!='@': passraise #IOError,"unrecognized key'format: "+repr(s default value)

else: raise IOError,"unrecognized format: "+repr(s)

# The name for @ is "", which properly sorts before everything.

self.name=s[1:index-1]

Line 56 ⟶ 107:

raise IOError,"no assignment in" +repr(s)

self.delete=assign[1]=='-'

self.lastkey=None if k is None else k.lastkey:

self.lastkey=None

else:

self.lastkey=k.lastkey

if not k.iskey and self.name.lower()<k.name.lower():

raise ValueError,"value %r precedes %r in input"%\

(k.name,self.name)

def valname(self):

Line 77 ⟶ 134:

if k!=self.key:

self.key=k

self.out.write("\r\n["+k+"]\r\n")

def terminated(s):

Line 105 ⟶ 162:

ret+=c

done=terminated(ret)

#printif >>sys.stderr,repr(c!=l)+'/'+repr(c)+": -> "+repr(ret)+": term="+str(done)\r\n"

if c!=l: ret+='\n'

return ret

Line 117 ⟶ 173:

sys.exit(2) # BAD_ARGS

allowKeyDelete=True

allowValueDelete=True

displayProgress=0

ci=codecs.lookup("utf_16")

fo=ci.streamreader(open(sys.argv[1],'rb'))

Line 125 ⟶ 184:

if fn.readline()!=head:

raise IOError,"different file headers"

out.write(head.rstrip('\r\n')+'"\r\n'")

o=n=line(None)

o.old=True

killing=False # the tree being deleted, if any

iters=0

while True:

iters+=1

if displayProgress and iters%displayProgress==0:

sys.stderr.write('#')

if o.old: o=line(nextLogical(fo),o)

if n.old: n=line(nextLogical(fn),n)

Line 140 ⟶ 204:

# values (since the values go with a previous key), and EOF comes after

# everything. Positive values mean that n comes first.

c=o.eof-n.eof or cmpkeycompare(o.lastkey,n.lastkey) or\
o.iskey-n.iskey or cmp(o.name.lower(),n.name.lower())

o.old=c<=0

n.old=c>=0

assert o.old or n.old,"not advancing in the file"

if killing and (o.eof or not isunder(o.lastkey,killing)): killing=False

Line 151 ⟶ 217:

# Delete a whole key if the new file is past all its subkeys.

# Note that n.lastkey!=o.name, because n must be a key.

if (n.eof or not isunder(n.lastkey,o.name)) and allowKeyDelete:

killing=o.name

out.write("\r\n[-"+o.name+"]\r\n")

elseelif allowValueDelete:

kp(o.lastkey)

out.write(o.valname()+"=-\r\n")

elif not n.iskey and n.str!=o.str:

kp(n.lastkey)

out.write(n.str)

out.write('"\r\n'")

if displayProgress: sys.stderr.write('\n')

</source>

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