def is_archive(f, formats=(None, ), filters=(None, )):
'''Check to see if the given file is actually an archive. The format parameter
can be used to specify which archive format is acceptable. If ommitted, all supported
archive formats will be checked. It opens the file using libarchive. If no error is
received, the file was successfully detected by the libarchive bidding process.
This procedure is quite costly, so you should avoid calling it unless you are reasonably
sure that the given file is an archive. In other words, you may wish to filter large
numbers of file names using is_archive_name() before double-checking the positives with
this function.
This function will return True if the file can be opened as an archive using the given
format(s)/filter(s).'''
if isinstance(f, str):
f = open(f, 'r')
a = _libarchive.archive_read_new()
for format in formats:
format = get_func(format, FORMATS, 0)
if format is None:
return False
format(a)
for filter in filters:
filter = get_func(filter, FILTERS, 0)
if filter is None:
return False
filter(a)
try:
try:
call_and_check(_libarchive.archive_read_open_fd, a, a, f.fileno(), BLOCK_SIZE)
return True
except:
return False
finally:
_libarchive.archive_read_close(a)
_libarchive.archive_read_free(a)
def is_archive(f, formats=(None, ), filters=(None, )):
'''Check to see if the given file is actually an archive. The format parameter
can be used to specify which archive format is acceptable. If ommitted, all supported
archive formats will be checked. It opens the file using libarchive. If no error is
received, the file was successfully detected by the libarchive bidding process.
This procedure is quite costly, so you should avoid calling it unless you are reasonably
sure that the given file is an archive. In other words, you may wish to filter large
numbers of file names using is_archive_name() before double-checking the positives with
this function.
This function will return True if the file can be opened as an archive using the given
format(s)/filter(s).'''
if isinstance(f, basestring):
f = file(f, 'r')
a = _libarchive.archive_read_new()
for format in formats:
format = get_func(format, FORMATS, 0)
if format is None:
return False
format(a)
for filter in filters:
filter = get_func(filter, FILTERS, 0)
if filter is None:
return False
filter(a)
try:
try:
call_and_check(_libarchive.archive_read_open_fd, a, a, f.fileno(), BLOCK_SIZE)
return True
except:
return False
finally:
_libarchive.archive_read_close(a)
_libarchive.archive_read_free(a)
def init(self):
if self.mode == 'r':
self._a = _libarchive.archive_read_new()
else:
self._a = _libarchive.archive_write_new()
self.format_func(self._a)
self.filter_func(self._a)
if self.mode == 'r':
call_and_check(_libarchive.archive_read_open_fd, self._a, self._a, self.f.fileno(), self.blocksize)
else:
call_and_check(_libarchive.archive_write_open_fd, self._a, self._a, self.f.fileno())
