milis/bin/rpm2cpio.py

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Python
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2017-12-25 17:53:32 +01:00
#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Lightweight RPM to CPIO converter.
# Copyright © 2008-2017 Rudá Moura. All rights reserved.
#
'''Extract cpio archive from RPM package.
rpm2cpio converts the RPM on standard input or first parameter to a CPIO archive on standard output.
Usage:
rpm2cpio < adjtimex-1.20-2.1.i386.rpm | cpio -it
./sbin/adjtimex
./usr/share/doc/adjtimex-1.20
./usr/share/doc/adjtimex-1.20/COPYING
./usr/share/doc/adjtimex-1.20/COPYRIGHT
./usr/share/doc/adjtimex-1.20/README
./usr/share/man/man8/adjtimex.8.gz
133 blocks
'''
from __future__ import print_function
import sys
import gzip
import subprocess
try:
from StringIO import StringIO
except ImportError:
from io import StringIO
HAS_LZMA_MODULE = True
try:
import lzma
except ImportError:
try:
import backports.lzma as lzma
except ImportError:
HAS_LZMA_MODULE = False
RPM_MAGIC = b'\xed\xab\xee\xdb'
GZIP_MAGIC = b'\x1f\x8b'
XZ_MAGIC = b'\xfd7zXZ\x00'
def gzip_decompress(data):
gzstream = StringIO(data)
gzipper = gzip.GzipFile(fileobj=gzstream)
data = gzipper.read()
return data
def xz_decompress(data):
if HAS_LZMA_MODULE:
return lzma.decompress(data)
unxz = subprocess.Popen(['unxz'],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE)
data = unxz.communicate(input=data)[0]
return data
def is_rpm(reader):
lead = reader.read(96)
return lead[0:4] == RPM_MAGIC
def extract_cpio(reader):
data = reader.read()
decompress = None
idx = data.find(XZ_MAGIC)
if idx != -1:
decompress = xz_decompress
pos = idx
idx = data.find(GZIP_MAGIC)
if idx != -1 and decompress is None:
decompress = gzip_decompress
pos = idx
if decompress is None:
return None
data = decompress(data[pos:])
return data
def rpm2cpio(stream_in=None, stream_out=None):
if stream_in is None:
stream_in = sys.stdin
if stream_out is None:
stream_out = sys.stdout
try:
reader = stream_in.buffer
writer = stream_out.buffer
except AttributeError:
reader = stream_in
writer = stream_out
if not is_rpm(reader):
raise IOError('the input is not a RPM package')
cpio = extract_cpio(reader)
if cpio is None:
raise IOError('could not find compressed cpio archive')
writer.write(cpio)
def main(args=None):
if args is None:
args = sys.argv
if args[1:]:
try:
fin = open(args[1])
rpm2cpio(fin)
fin.close()
except IOError as e:
print('Error:', args[1], e)
sys.exit(1)
except OSError as e:
print('Error: could not find lzma extractor')
print("Please, install Python's lzma module or the xz utility")
sys.exit(1)
else:
try:
rpm2cpio()
except IOError as e:
print('Error:', e)
sys.exit(1)
except OSError as e:
print('Error: could not find lzma extractor')
print("Please install Python's lzma module or the xz utility")
sys.exit(1)
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
print('Interrupted!')