Merge branch 'master' of https://github.com/ahupp/python-magic into abi3-wheels

* 'master' of https://github.com/ahupp/python-magic:
  log warning on ctypes load error, adapted from ahupp#279
  smartos support, adapted from ahupp#132
  rename no_json test to avoid duplicate function definitions
  handle unknown platforms gracefully in loader.py
  Clean up loader.py

Author: ddelange

README.md

@@ -92,6 +92,10 @@ brew install libmagic
 port install file
 ```
 
+### SmartOS:
+- Install libmagic for source https://github.com/threatstack/libmagic/
+- Depending on your ./configure --prefix settings set your LD_LIBRARY_PATH to <prefix>/lib
+
 ### Troubleshooting
 
 - 'MagicException: could not find any magic files!': some

magic/loader.py

@@ -1,74 +1,102 @@
 from ctypes.util import find_library
 import ctypes
+import sys
 import glob
 import os
+import logging
 import subprocess
-import sys
+
+logger = logging.getLogger(__name__)
+here = os.path.dirname(__file__)
+
+def _lib_candidates_linux():
+    """Yield possible libmagic library names on Linux."""
+    prefixes = ('libmagic.so.1', 'libmagic.so')
+
+    for i in prefixes:
+        # libmagic bundled in the wheel
+        yield os.path.join(here, i)
+        # libmagic in the current working directory
+        yield os.path.join(os.path.abspath('.'), i)
+        # libmagic install from source default destination path
+        yield os.path.join('/usr/local/lib', i)
+        # on some linux systems (musl/alpine), find_library('magic') returns None
+        # first try finding libmagic using ldconfig
+        # otherwise fall back to /usr/lib/
+        yield subprocess.check_output(
+            "( ldconfig -p | grep '{0}' | grep -o '/.*' ) || echo '/usr/lib/{0}'".format(i),
+            shell=True,
+            universal_newlines=True,
+        ).strip()
+
+
+def _lib_candidates_macos():
+    """Yield possible libmagic library names on macOS."""
+    paths = [
+        # libmagic bundled in the wheel
+        here,
+        # libmagic in the current working directory
+        os.path.abspath('.'),
+        # libmagic in other common sources like homebrew
+        '/opt/local/lib',
+        '/usr/local/lib',
+        '/opt/homebrew/lib',
+    ] + glob.glob('/usr/local/Cellar/libmagic/*/lib')
+
+    for i in paths:
+        yield os.path.join(i, 'libmagic.dylib')
+
+
+def _lib_candidates_windows():
+    """Yield possible libmagic library names on Windows."""
+    prefixes = (
+        "libmagic",
+        "magic1",
+        "magic-1",
+        "cygmagic-1",
+        "libmagic-1",
+        "msys-magic-1",
+    )
+
+    for i in prefixes:
+        # libmagic bundled in the wheel
+        yield os.path.join(here, '%s.dll' % i)
+        # libmagic in the current working directory
+        yield os.path.join(os.path.abspath('.'), '%s.dll' % i)
+        # find_library searches in %PATH% but not the current directory
+        yield find_library(i)
+
 
 def _lib_candidates():
-    here = os.path.dirname(__file__)
-
-    if sys.platform == 'darwin':
-
-        paths = [
-            # libmagic bundled in the wheel
-            here,
-            # libmagic in the current working directory
-            os.path.abspath('.'),
-            # libmagic in other common sources like homebrew
-            '/opt/local/lib',
-            '/usr/local/lib',
-            '/opt/homebrew/lib',
-        ] + glob.glob('/usr/local/Cellar/libmagic/*/lib')
-
-        for i in paths:
-            yield os.path.join(i, 'libmagic.dylib')
-
-    elif sys.platform in ('win32', 'cygwin'):
-
-        prefixes = ['libmagic', 'magic1', 'magic-1', 'cygmagic-1', 'libmagic-1', 'msys-magic-1']
-
-        for i in prefixes:
-            # libmagic bundled in the wheel
-            yield os.path.join(here, '%s.dll' % i)
-            # libmagic in the current working directory
-            yield os.path.join(os.path.abspath('.'), '%s.dll' % i)
-            # find_library searches in %PATH% but not the current directory
-            yield find_library(i)
-
-    elif sys.platform == 'linux':
-
-        prefixes = ['libmagic.so.1', 'libmagic.so']
-
-        for i in prefixes:
-            # libmagic bundled in the wheel
-            yield os.path.join(here, i)
-            # libmagic in the current working directory
-            yield os.path.join(os.path.abspath('.'), i)
-            # libmagic install from source default destination path
-            yield os.path.join('/usr/local/lib', i)
-            # on some linux systems (musl/alpine), find_library('magic') returns None
-            # first try finding libmagic using ldconfig
-            # otherwise fall back to /usr/lib/
-            yield subprocess.check_output(
-                "( ldconfig -p | grep '{0}' | grep -o '/.*' ) || echo '/usr/lib/{0}'".format(i),
-                shell=True,
-                universal_newlines=True,
-            ).strip()
+    func = {
+        "cygwin": _lib_candidates_windows,
+        "darwin": _lib_candidates_macos,
+        "linux": _lib_candidates_linux,
+        "win32": _lib_candidates_windows,
+        "sunos5": _lib_candidates_linux, 
+    }.get(sys.platform)
+    if func is None:
+        raise ImportError("python-magic: Unsupported platform: " + sys.platform)
+    # When we drop legacy Python, we can just `yield from func()`
+    for path in func():
+        yield path
 
     # fallback
     yield find_library('magic')
 
 
 def load_lib():
-
     for lib in _lib_candidates():
         # find_library returns None when lib not found
         if lib is None:
             continue
+        if not os.path.exists(lib):
+            continue
+
         try:
             return ctypes.CDLL(lib)
-        except OSError:  # file not found
-            pass
-    raise ImportError('failed to find libmagic. Check your installation')
+        except OSError:
+            logger.warning("Failed to load: " + lib, exc_info=True)
 
+    # It is better to raise an ImportError since we are importing magic module
+    raise ImportError("python-magic: failed to find libmagic. Check your installation")

test/python_magic_test.py

@@ -196,7 +196,8 @@ def test_descriptions_no_json(self):
             buf_equals_file=True,
         )
 
-    def test_descriptions_no_json(self):
+    def test_descriptions_no_json_unchanged(self):
+        # verify non-json results are unchanged
         m = magic.Magic(check_json=False)
         os.environ["TZ"] = "UTC"  # To get last modified date of test.gz in UTC
         try: