Merge pull request #227 from psrok1/magic-descriptor

Added support for magic_descriptor routine

3 files changed, 43 insertions, 0 deletions

diff --git a/magic.py b/magic.py
index ccddf46..3b351e2 100644
--- a/magic.py
+++ b/magic.py
@@ -114,6 +114,13 @@ class Magic:
             except MagicException as e:
                 return self._handle509Bug(e)
 
+    def from_descriptor(self, fd):
+        with self.lock:
+            try:
+                return maybe_decode(magic_descriptor(self.cookie, fd))
+            except MagicException as e:
+                return self._handle509Bug(e)
+
     def _handle509Bug(self, e):
         # libmagic 5.09 has a bug where it might fail to identify the
         # mimetype of a file and returns null from magic_file (and
@@ -180,6 +187,20 @@ def from_buffer(buffer, mime=False):
     return m.from_buffer(buffer)
 
 
+def from_descriptor(fd, mime=False):
+    """
+    Accepts a file descriptor and returns the detected filetype.  Return
+    value is the mimetype if mime=True, otherwise a human readable
+    name.
+
+    >>> f = open("testdata/test.pdf")
+    >>> magic.from_descriptor(f.fileno())
+    'PDF document, version 1.2'
+    """
+    m = _get_magic_type(mime)
+    return m.from_descriptor(fd)
+
+
 libmagic = None
 # Let's try to find magic or magic1
 dll = ctypes.util.find_library('magic') \
@@ -287,6 +308,7 @@ _magic_file.errcheck = errorcheck_null
 def magic_file(cookie, filename):
     return _magic_file(cookie, coerce_filename(filename))
 
+
 _magic_buffer = libmagic.magic_buffer
 _magic_buffer.restype = c_char_p
 _magic_buffer.argtypes = [magic_t, c_void_p, c_size_t]
@@ -297,6 +319,16 @@ def magic_buffer(cookie, buf):
     return _magic_buffer(cookie, buf, len(buf))
 
 
+_magic_descriptor = libmagic.magic_descriptor
+_magic_descriptor.restype = c_char_p
+_magic_descriptor.argtypes = [magic_t, c_int]
+_magic_descriptor.errcheck = errorcheck_null
+
+
+def magic_descriptor(cookie, fd):
+    return _magic_descriptor(cookie, fd)
+
+
 _magic_load = libmagic.magic_load
 _magic_load.restype = c_int
 _magic_load.argtypes = [magic_t, c_char_p]
@@ -306,6 +338,7 @@ _magic_load.errcheck = errorcheck_negative_one
 def magic_load(cookie, filename):
     return _magic_load(cookie, coerce_filename(filename))
 
+
 magic_setflags = libmagic.magic_setflags
 magic_setflags.restype = c_int
 magic_setflags.argtypes = [magic_t, c_int]
diff --git a/magic.pyi b/magic.pyi
index d0df01a..8d5f38f 100644
--- a/magic.pyi
+++ b/magic.pyi
@@ -13,12 +13,14 @@ class Magic:
     def __init__(self, mime: bool = ..., magic_file: Optional[Any] = ..., mime_encoding: bool = ..., keep_going: bool = ..., uncompress: bool = ..., raw: bool = ...) -> None: ...
     def from_buffer(self, buf: Union[bytes, str]) -> Text: ...
     def from_file(self, filename: Union[bytes, str]) -> Text: ...
+    def from_descriptor(self, fd: int, mime: bool = ...) -> Text: ...
     def setparam(self, param: Any, val: Any): ...
     def getparam(self, param: Any): ...
     def __del__(self) -> None: ...
 
 def from_file(filename: Union[bytes, str], mime: bool = ...) -> Text: ...
 def from_buffer(buffer: Union[bytes, str], mime: bool = ...) -> Text: ...
+def from_descriptor(fd: int, mime: bool = ...) -> Text: ...
 
 libmagic: Any
 dll: Any
@@ -39,6 +41,7 @@ magic_errno: Any
 
 def magic_file(cookie: Any, filename: Any): ...
 def magic_buffer(cookie: Any, buf: Any): ...
+def magic_descriptor(cookie: Any, fd: int): ...
 def magic_load(cookie: Any, filename: Any): ...
 
 magic_setflags: Any
diff --git a/test/test.py b/test/test.py
index eb5af89..3097e6e 100755
--- a/test/test.py
+++ b/test/test.py
@@ -56,6 +56,13 @@ class MagicTest(unittest.TestCase):
         self.assertEqual('application/pdf',
                          magic.from_file(filename.encode('utf-8'), mime=True))
 
+    def test_from_descriptor_str_and_bytes(self):
+        with open(os.path.join(self.TESTDATA_DIR, "test.pdf")) as f:
+            self.assertEqual('application/pdf',
+                             magic.from_descriptor(f.fileno(), mime=True))
+            self.assertEqual('application/pdf',
+                             magic.from_descriptor(f.fileno(), mime=True))
+
     def test_from_buffer_str_and_bytes(self):
         m = magic.Magic(mime=True)