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# $Id$
#
# Copyright (C) 1997 Klee Dienes <klee@mit.edu>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
import sys, string, subfile, os, stat
def parse_string (s):
e = len (s) - 1
while ((e != -1) and (s[e] == '\0')):
e = e - 1
return s[0:e+1]
def parse_num (s):
b = 0
e = len (s) - 1
while ((e != -1) and ((s[e] == '\0') or (s[e] == ' '))):
e = e - 1
while ((b <= e) and (s[b] == ' ')):
b = b + 1
s = s[b:e+1]
if (s == ''):
return -1L
return string.atol (s, 8)
def parse_header (s):
r = {}
r['name'] = parse_string (s[0:100])
r['mode'] = parse_num (s[100:108])
r['uid'] = parse_num (s[108:116])
r['gid'] = parse_num (s[116:124])
r['size'] = parse_num (s[124:136])
r['time'] = parse_num (s[136:148])
r['checksum'] = parse_num (s[148:156])
r['type'] = s[156:157]
r['link'] = parse_string (s[157:257])
r['magic'] = s[257:265]
r['uname'] = parse_string (s[265:297])
r['gname'] = parse_string (s[297:329])
r['dmaj'] = parse_num (s[329:337])
r['dmin'] = parse_num (s[337:345])
return r
def fseek (f, i):
try:
f.seek (i, 0)
return
except:
pass
while (f.tell () < i):
f.read (min (4096, i - f.tell()))
if (i < f.tell()):
raise ValueError, 'unable to seek backwards on stream'
def parse_file (f, p):
i = 0
while 1:
fseek (f, i)
s = f.read (512)
#print 'tar.parse: read %d bytes at %d' % (len (s), i)
last = 0
if (len (s) != 512):
last = 1
r = parse_header (s)
nblocks = (r['size'] + 511) / 512
r['offset'] = i + 512
i = i + ((nblocks + 1) * 512)
if (r['name'] != ''):
r['file'] = subfile.subfile (f, r['offset'], r['size'])
p (f, r)
if (last):
return
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