Files
mc_uadf/ulha
2013-05-05 21:33:46 +02:00

330 lines
10 KiB
Python
Executable File

#! /usr/bin/env python
"""
Lha Virtual filesystem executive for Midnight Commander.
Tested against python 2.7, lha[1] 1.14 and mc 4.8.7
[1] http://lha.sourceforge.jp
Changelog:
1.0 Initial release
Author: Roman 'gryf' Dobosz <gryf73@gmail.com>
Date: 2013-05-05
Version: 1.0
Licence: BSD
"""
import os
import sys
import re
import shutil
from subprocess import call, check_call, check_output, CalledProcessError
from tempfile import mkdtemp, mkstemp
# Define which archiver you are using with appropriate options
ARCHIVER = "lha"
CMDS = {"list": "lq",
"read": "pq",
"write": "aq",
"delete": "dq"}
LINE_LHD = re.compile("^(?P<perms>[d-][rswx-]{9})"
"\s+(?P<uid>\d+)/"
"(?P<gid>\d+)"
"\s+(?P<size>\d+)"
"\s+(\*{6}|\d+\.\d%)"
"\s(?P<month>[JFMASOND][a-z]{2})\s+" # month
"(?P<day>\d+)\s+" # day
"(?P<yh>\d{4}|(\d{2}:\d{2}))" # year/hour
"\s(?P<fpath>.*)")
LINE_LHx = re.compile("^(?P<perms>(\[generic\])|(\[unknown\])|([d-][rswx-]{9}))"
"\s+(?P<size>\d+)"
"\s+(\*{6}|\d+\.\d%)"
"\s(?P<month>[JFMASOND][a-z]{2})\s+" # month
"(?P<day>\d+)\s+" # day
"(?P<yh>\d{4}|(\d{2}:\d{2}))" # year/hour
"\s(?P<fpath>.*)")
class Archive(object):
"""Archive handle. Provides interface to MC's extfs subsystem"""
def __init__(self, fname):
"""Prepare archive content for operations"""
self._filemap = {}
self._arch = fname
self._pattern = None
self._uid = str(os.getuid())
self._gid = str(os.getgid())
self._contents = self._get_dir()
def _identify(self):
"""Check for lha header"""
pat_map = {"-lhd-": LINE_LHD,
"-lh0-": LINE_LHx,
"-lh1-": LINE_LHx,
"-lh5-": LINE_LHx,
"-lh6-": LINE_LHx}
fobj = open(self._arch)
fobj.seek(2)
ident = fobj.read(5)
fobj.close()
return pat_map[ident]
def _map_name(self, name):
"""MC still have a bug in extfs subsystem, in case of filepaths with
leading space. This is workaround to this bug, which replaces leading
space with tilda. Real name is remembered in _filemap attribute and
used in real operations."""
if name.startswith(" "):
new_name = "".join(["~", name[1:]])
self._filemap[new_name] = name
return new_name
return name
def _get_real_name(self, name):
"""Get real filepath of the file. See _map_name docstring for
details."""
new_name = self._filemap.get(name)
if new_name:
return new_name
return name
def _get_dir(self):
"""Prepare archive file listing"""
if not self._pattern:
self._pattern = self._identify()
self._filemap = {}
contents = []
if self._pattern == LINE_LHx:
perms = "-rw-r--r--"
out = self._call_command("list")
if not out:
return
for line in out.split("\n"):
if line.endswith("/"):
line = line[:-1]
if self._pattern == LINE_LHx:
perms = "drw-r--r--"
match = self._pattern.match(line)
if not match:
continue
entry = match.groupdict()
# UID and GID sometimes can have strange values depending on
# the information that was written into archive. Most of the
# times I was dealing with Amiga lha archives, so that i don't
# really care about real user/group
entry['uid'] = self._uid
entry['gid'] = self._gid
if self._pattern == LINE_LHx:
entry['perms'] = perms
entry['display_name'] = self._map_name(entry['fpath'])
contents.append(entry)
return contents
def _call_command(self, cmd, src=None, dst=None):
"""
Return status of the provided command, which can be one of:
write
read
delete
list
"""
command = [ARCHIVER, CMDS.get(cmd), self._arch]
if src and dst:
command.append(src)
command.append(dst)
elif src or dst:
command.append(src and src or dst)
try:
output = check_output(command)
except CalledProcessError:
return None
return output
def list(self):
"""Output contents of the archive to stdout"""
for entry in self._contents:
sys.stdout.write("%(perms)s 1 %(uid)-8s %(gid)-8s %(size)8s "
"%(month)s %(day)s %(yh)s %(display_name)s\n" %
entry)
return 0
def rm(self, dst):
"""Remove file from archive"""
dst = self._get_real_name(dst)
# deleting with quiet option enabled will output nothing, so we get
# empty string here or None in case of error. Not smart.
if self._call_command('delete', dst=dst) is None:
return 1
return 0
def run(self, dst):
"""Execute file out of archive"""
fdesc, tmp_file = mkstemp()
os.close(fdesc)
result = 0
if self.copyout(dst, tmp_file) != 0:
result = 1
os.chmod(tmp_file, int("700", 8))
try:
result = call([tmp_file])
finally:
try:
os.unlink(tmp_file)
except OSError:
pass
return result
def mkdir(self, dst):
"""Create empty directory in archive"""
return self.copyin(dst)
def copyin(self, dst, src=None):
"""Copy file to the archive or create direcotry inside.
If src is empty, create empty directory with dst name."""
current_dir = os.path.abspath(os.curdir)
tmpdir = mkdtemp()
arch_abspath = os.path.realpath(self._arch)
os.chdir(tmpdir)
if src:
os.makedirs(os.path.dirname(dst))
os.link(src, dst)
else:
os.makedirs(dst)
try:
result = check_call([ARCHIVER, CMDS["write"], arch_abspath, dst])
except CalledProcessError:
return 1
finally:
os.chdir(current_dir)
shutil.rmtree(tmpdir)
return result
def copyout(self, src, dst):
"""Copy file out form archive."""
src = self._get_real_name(src)
fobj = open(dst, "wb")
try:
result = check_call([ARCHIVER, CMDS['read'], self._arch, src],
stdout=fobj)
except CalledProcessError:
return 1
finally:
fobj.close()
return result
CALL_MAP = {'list': lambda a: Archive(a.arch).list(),
'copyin': lambda a: Archive(a.arch).copyin(a.src, a.dst),
'copyout': lambda a: Archive(a.arch).copyout(a.src, a.dst),
'mkdir': lambda a: Archive(a.arch).mkdir(a.dst),
'rm': lambda a: Archive(a.arch).rm(a.dst),
'run': lambda a: Archive(a.arch).run(a.dst)}
def parse_args():
"""Use ArgumentParser to check for script arguments and execute."""
parser = ArgumentParser()
subparsers = parser.add_subparsers(help='supported commands')
parser_list = subparsers.add_parser('list', help="List contents of "
"archive")
parser_copyin = subparsers.add_parser('copyin', help="Copy file into "
"archive")
parser_copyout = subparsers.add_parser('copyout', help="Copy file out of "
"archive")
parser_rm = subparsers.add_parser('rm', help="Delete file in archive")
parser_mkdir = subparsers.add_parser('mkdir', help="Create directory in "
"archive")
parser_run = subparsers.add_parser('run', help="Execute archived file")
parser_list.add_argument('arch', help="archive filename")
parser_list.set_defaults(func=CALL_MAP['list'])
parser_copyin.add_argument('arch', help="archive filename")
parser_copyin.add_argument('src', help="source filename")
parser_copyin.add_argument('dst', help="destination filename (to be "
"written into archive)")
parser_copyin.set_defaults(func=CALL_MAP['copyin'])
parser_copyout.add_argument('arch', help="archive filename")
parser_copyout.add_argument('src', help="source filename (to be read from"
" archive")
parser_copyout.add_argument('dst', help="destination filename")
parser_copyout.set_defaults(func=CALL_MAP['copyout'])
parser_rm.add_argument('arch', help="archive filename")
parser_rm.add_argument('dst', help="File inside archive to be deleted")
parser_rm.set_defaults(func=CALL_MAP['rm'])
parser_mkdir.add_argument('arch', help="archive filename")
parser_mkdir.add_argument('dst', help="Directory name inside archive to "
"be created")
parser_mkdir.set_defaults(func=CALL_MAP['mkdir'])
parser_run.add_argument('arch', help="archive filename")
parser_run.add_argument('dst', help="File to be executed")
parser_run.set_defaults(func=CALL_MAP['run'])
args = parser.parse_args()
return args.func(args)
def no_parse():
"""Failsafe argument "parsing". Note, that it blindly takes positional
arguments without checking them. In case of wrong arguments it will
silently exit"""
try:
if sys.argv[1] not in ('list', 'copyin', 'copyout', 'rm', 'mkdir',
"run"):
sys.exit(2)
except IndexError:
sys.exit(2)
class Arg(object):
"""Mimic argparse object"""
dst = None
src = None
arch = None
arg = Arg()
try:
arg.arch = sys.argv[2]
if sys.argv[1] in ('copyin', 'copyout'):
arg.src = sys.argv[3]
arg.dst = sys.argv[4]
elif sys.argv[1] in ('rm', 'run', 'mkdir'):
arg.dst = sys.argv[3]
except IndexError:
sys.exit(2)
return CALL_MAP[sys.argv[1]](arg)
if __name__ == "__main__":
try:
from argparse import ArgumentParser
PARSE_FUNC = parse_args
except ImportError:
PARSE_FUNC = no_parse
sys.exit(PARSE_FUNC())