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Diffstat (limited to 'magic.py')
| -rw-r--r-- | magic.py | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/magic.py b/magic.py new file mode 100644 index 0000000..60b999b --- /dev/null +++ b/magic.py @@ -0,0 +1,207 @@ +""" +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): + """ + Create a new libmagic wrapper. + + mime - if True, mimetypes are returned instead of textual descriptions + magic_file - use a mime database other than the system default + + """ + flags = MAGIC_NONE + if mime: + flags |= MAGIC_MIME + + 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): + try: + magic_close(self.cookie) + except Exception, e: + print "got thig: ", e + + +_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 = ctypes.CDLL(ctypes.util.find_library('magic')) + +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_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 |