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"""
magic is a wrapper around the libmagic file identification library.
See README for more information.
Usage:
>>> import magic
>>> magic.from_file("testdata/test.pdf")
'PDF document, version 1.2'
>>> magic.from_file("testdata/test.pdf", mime=True)
'application/pdf'
>>> magic.from_buffer(open("testdata/test.pdf").read(1024))
'PDF document, version 1.2'
>>>
"""
import os.path
import ctypes
import ctypes.util
from ctypes import c_char_p, c_int, c_size_t, c_void_p
class MagicException(Exception): pass
class Magic:
"""
Magic is a wrapper around the libmagic C library.
"""
def __init__(self, mime=False, magic_file=None, mime_encoding=False):
"""
Create a new libmagic wrapper.
mime - if True, mimetypes are returned instead of textual descriptions
mime_encoding - if True, codec is returned
magic_file - use a mime database other than the system default
"""
flags = MAGIC_NONE
if mime:
flags |= MAGIC_MIME
elif mime_encoding:
flags |= MAGIC_MIME_ENCODING
self.cookie = magic_open(flags)
magic_load(self.cookie, magic_file)
def from_buffer(self, buf):
"""
Identify the contents of `buf`
"""
return magic_buffer(self.cookie, buf)
def from_file(self, filename):
"""
Identify the contents of file `filename`
raises IOError if the file does not exist
"""
if not os.path.exists(filename):
raise IOError("File does not exist: " + filename)
return magic_file(self.cookie, filename)
def __del__(self):
# during shutdown magic_close may have been cleared already
if self.cookie and magic_close:
magic_close(self.cookie)
self.cookie = None
_magic_mime = None
_magic = None
def _get_magic_mime():
global _magic_mime
if not _magic_mime:
_magic_mime = Magic(mime=True)
return _magic_mime
def _get_magic():
global _magic
if not _magic:
_magic = Magic()
return _magic
def _get_magic_type(mime):
if mime:
return _get_magic_mime()
else:
return _get_magic()
def from_file(filename, mime=False):
m = _get_magic_type(mime)
return m.from_file(filename)
def from_buffer(buffer, mime=False):
m = _get_magic_type(mime)
return m.from_buffer(buffer)
libmagic = None
# Let's try to find magic or magic1
dll = ctypes.util.find_library('magic') or ctypes.util.find_library('magic1')
# This is necessary because find_library returns None if it doesn't find the library
if dll:
libmagic = ctypes.CDLL(dll)
if not libmagic or not libmagic._name:
import sys
platform_to_lib = {'darwin': ['/opt/local/lib/libmagic.dylib',
'/usr/local/lib/libmagic.dylib',
'/usr/local/Cellar/libmagic/5.10/lib/libmagic.dylib'],
'win32': ['magic1.dll']}
for dll in platform_to_lib.get(sys.platform, []):
try:
libmagic = ctypes.CDLL(dll)
except OSError:
pass
if not libmagic or not libmagic._name:
# It is better to raise an ImportError since we are importing magic module
raise ImportError('failed to find libmagic. Check your installation')
magic_t = ctypes.c_void_p
def errorcheck(result, func, args):
err = magic_error(args[0])
if err is not None:
raise MagicException(err)
else:
return result
magic_open = libmagic.magic_open
magic_open.restype = magic_t
magic_open.argtypes = [c_int]
magic_close = libmagic.magic_close
magic_close.restype = None
magic_close.argtypes = [magic_t]
magic_error = libmagic.magic_error
magic_error.restype = c_char_p
magic_error.argtypes = [magic_t]
magic_errno = libmagic.magic_errno
magic_errno.restype = c_int
magic_errno.argtypes = [magic_t]
magic_file = libmagic.magic_file
magic_file.restype = c_char_p
magic_file.argtypes = [magic_t, c_char_p]
magic_file.errcheck = errorcheck
_magic_buffer = libmagic.magic_buffer
_magic_buffer.restype = c_char_p
_magic_buffer.argtypes = [magic_t, c_void_p, c_size_t]
_magic_buffer.errcheck = errorcheck
def magic_buffer(cookie, buf):
return _magic_buffer(cookie, buf, len(buf))
magic_load = libmagic.magic_load
magic_load.restype = c_int
magic_load.argtypes = [magic_t, c_char_p]
magic_load.errcheck = errorcheck
magic_setflags = libmagic.magic_setflags
magic_setflags.restype = c_int
magic_setflags.argtypes = [magic_t, c_int]
magic_check = libmagic.magic_check
magic_check.restype = c_int
magic_check.argtypes = [magic_t, c_char_p]
magic_compile = libmagic.magic_compile
magic_compile.restype = c_int
magic_compile.argtypes = [magic_t, c_char_p]
MAGIC_NONE = 0x000000 # No flags
MAGIC_DEBUG = 0x000001 # Turn on debugging
MAGIC_SYMLINK = 0x000002 # Follow symlinks
MAGIC_COMPRESS = 0x000004 # Check inside compressed files
MAGIC_DEVICES = 0x000008 # Look at the contents of devices
MAGIC_MIME = 0x000010 # Return a mime string
MAGIC_MIME_ENCODING = 0x000400 # Return the MIME encoding
MAGIC_CONTINUE = 0x000020 # Return all matches
MAGIC_CHECK = 0x000040 # Print warnings to stderr
MAGIC_PRESERVE_ATIME = 0x000080 # Restore access time on exit
MAGIC_RAW = 0x000100 # Don't translate unprintable chars
MAGIC_ERROR = 0x000200 # Handle ENOENT etc as real errors
MAGIC_NO_CHECK_COMPRESS = 0x001000 # Don't check for compressed files
MAGIC_NO_CHECK_TAR = 0x002000 # Don't check for tar files
MAGIC_NO_CHECK_SOFT = 0x004000 # Don't check magic entries
MAGIC_NO_CHECK_APPTYPE = 0x008000 # Don't check application type
MAGIC_NO_CHECK_ELF = 0x010000 # Don't check for elf details
MAGIC_NO_CHECK_ASCII = 0x020000 # Don't check for ascii files
MAGIC_NO_CHECK_TROFF = 0x040000 # Don't check ascii/troff
MAGIC_NO_CHECK_FORTRAN = 0x080000 # Don't check ascii/fortran
MAGIC_NO_CHECK_TOKENS = 0x100000 # Don't check ascii/tokens
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