Merge pull request #93 from tipabu/non-utf8-values

Various dump-related fixes

2 files changed, 157 insertions, 22 deletions

diff --git a/xattr/tests/test_tool.py b/xattr/tests/test_tool.py
new file mode 100644
index 0000000..644364f
--- /dev/null
+++ b/xattr/tests/test_tool.py
@@ -0,0 +1,117 @@
+import contextlib
+import errno
+import io
+import os
+import shutil
+import sys
+import tempfile
+import unittest
+import uuid
+
+import xattr
+import xattr.tool
+
+
+class TestTool(unittest.TestCase):
+    def setUp(self):
+        self.test_dir = tempfile.mkdtemp()
+        self.addCleanup(shutil.rmtree, self.test_dir)
+
+        orig_stdout = sys.stdout
+
+        def unpatch_stdout(sys=sys, orig_stdout=orig_stdout):
+            sys.stdout = orig_stdout
+
+        self.addCleanup(unpatch_stdout)
+        sys.stdout = self.mock_stdout = io.StringIO()
+
+    def getoutput(self):
+        value = self.mock_stdout.getvalue()
+        self.mock_stdout.seek(0)
+        self.mock_stdout.truncate(0)
+        return value
+
+    @contextlib.contextmanager
+    def temp_file(self):
+        test_file = os.path.join(self.test_dir, str(uuid.uuid4()))
+        fd = os.open(test_file, os.O_CREAT | os.O_WRONLY)
+        try:
+            yield test_file, fd
+        finally:
+            os.close(fd)
+
+    def set_xattr(self, fd, name, value):
+        try:
+            xattr.setxattr(fd, name, value)
+        except OSError as e:
+            if e.errno == errno.ENOTSUP:
+                raise unittest.SkipTest('xattrs are not supported')
+            raise
+
+    def test_utf8(self):
+        with self.temp_file() as (file_path, fd):
+            self.set_xattr(fd, 'user.test-utf8',
+                           u'\N{SNOWMAN}'.encode('utf8'))
+            self.set_xattr(fd, 'user.test-utf8-and-nul',
+                           u'\N{SNOWMAN}\0'.encode('utf8'))
+
+        xattr.tool.main(['prog', '-p', 'user.test-utf8', file_path])
+        self.assertEqual(u'\N{SNOWMAN}\n', self.getoutput())
+
+        xattr.tool.main(['prog', '-p', 'user.test-utf8-and-nul', file_path])
+        self.assertEqual(u'''
+0000   E2 98 83 00                                        ....
+
+'''.lstrip(), self.getoutput())
+
+        xattr.tool.main(['prog', '-l', file_path])
+        output = self.getoutput()
+        self.assertIn(u'user.test-utf8: \N{SNOWMAN}\n', output)
+        self.assertIn(u'''
+user.test-utf8-and-nul:
+0000   E2 98 83 00                                        ....
+
+'''.lstrip(), output)
+
+    def test_non_utf8(self):
+        with self.temp_file() as (file_path, fd):
+            self.set_xattr(fd, 'user.test-not-utf8', b'cannot\xffdecode')
+
+        xattr.tool.main(['prog', '-p', 'user.test-not-utf8', file_path])
+        self.assertEqual(u'''
+0000   63 61 6E 6E 6F 74 FF 64 65 63 6F 64 65             cannot.decode
+
+'''.lstrip(), self.getoutput())
+
+        xattr.tool.main(['prog', '-l', file_path])
+        self.assertIn(u'''
+user.test-not-utf8:
+0000   63 61 6E 6E 6F 74 FF 64 65 63 6F 64 65             cannot.decode
+
+'''.lstrip(), self.getoutput())
+
+    def test_nul(self):
+        with self.temp_file() as (file_path, fd):
+            self.set_xattr(fd, 'user.test', b'foo\0bar')
+            self.set_xattr(fd, 'user.test-long',
+                           b'some rather long value with\0nul\0chars in it')
+
+        xattr.tool.main(['prog', '-p', 'user.test', file_path])
+        self.assertEqual(u'''
+0000   66 6F 6F 00 62 61 72                               foo.bar
+
+'''.lstrip(), self.getoutput())
+
+        xattr.tool.main(['prog', '-p', 'user.test-long', file_path])
+        self.assertEqual(u'''
+0000   73 6F 6D 65 20 72 61 74 68 65 72 20 6C 6F 6E 67    some rather long
+0010   20 76 61 6C 75 65 20 77 69 74 68 00 6E 75 6C 00     value with.nul.
+0020   63 68 61 72 73 20 69 6E 20 69 74                   chars in it
+
+'''.lstrip(), self.getoutput())
+
+        xattr.tool.main(['prog', '-l', file_path])
+        self.assertIn(u'''
+0000   66 6F 6F 00 62 61 72                               foo.bar
+
+'''.lstrip(), self.getoutput())
diff --git a/xattr/tool.py b/xattr/tool.py
index a7cfb47..0623560 100755
--- a/xattr/tool.py
+++ b/xattr/tool.py
@@ -62,12 +62,19 @@ def usage(e=None):
     print("  -z: compress or decompress (if compressed) attribute value in zip format")
 
     if e:
-        sys.exit(64)
+        return 64
     else:
-        sys.exit(0)
+        return 0
 
 
-_FILTER = ''.join([(len(repr(chr(x))) == 3) and chr(x) or '.' for x in range(256)])
+if sys.version_info < (3,):
+    ascii = repr
+    uchr = unichr
+else:
+    uchr = chr
+
+
+_FILTER = u''.join([(len(ascii(chr(x))) == 3) and uchr(x) or u'.' for x in range(256)])
 
 
 def _dump(src, length=16):
@@ -80,11 +87,11 @@ def _dump(src, length=16):
     return ''.join(result)
 
 
-def main():
+def main(argv):
     try:
-        (optargs, args) = getopt.getopt(sys.argv[1:], "hlpwdzs", ["help"])
+        (optargs, args) = getopt.getopt(argv[1:], "hlpwdzs", ["help"])
     except getopt.GetoptError as e:
-        usage(e)
+        return usage(e)
 
     attr_name = None
     long_format = False
@@ -98,7 +105,7 @@ def main():
 
     for opt, arg in optargs:
         if opt in ("-h", "--help"):
-            usage()
+            return usage()
         elif opt == "-l":
             long_format = True
         elif opt == "-s":
@@ -106,31 +113,31 @@ def main():
         elif opt == "-p":
             read = True
             if write or delete:
-                usage("-p not allowed with -w or -d")
+                return usage("-p not allowed with -w or -d")
         elif opt == "-w":
             write = True
             if read or delete:
-                usage("-w not allowed with -p or -d")
+                return usage("-w not allowed with -p or -d")
         elif opt == "-d":
             delete = True
             if read or write:
-                usage("-d not allowed with -p or -w")
+                return usage("-d not allowed with -p or -w")
         elif opt == "-z":
             compress = zlib.compress
             decompress = zlib.decompress
 
     if write or delete:
         if long_format:
-            usage("-l not allowed with -w or -p")
+            return usage("-l not allowed with -w or -p")
 
     if read or write or delete:
         if not args:
-            usage("No attr_name")
+            return usage("No attr_name")
         attr_name = args.pop(0)
 
     if write:
         if not args:
-            usage("No attr_value")
+            return usage("No attr_value")
         attr_value = args.pop(0).encode('utf-8')
 
     if len(args) > 1:
@@ -188,31 +195,42 @@ def main():
                 file_prefix = ""
 
             for attr_name in attr_names:
+                should_dump = False
                 try:
                     try:
                         attr_value = decompress(attrs[attr_name])
                     except zlib.error:
                         attr_value = attrs[attr_name]
-                    attr_value = attr_value.decode('utf-8')
+                    try:
+                        if b'\0' in attr_value:
+                            # force dumping
+                            raise NullsInString
+                        attr_value = attr_value.decode('utf-8')
+                    except (UnicodeDecodeError, NullsInString):
+                        attr_value = attr_value.decode('latin-1')
+                        should_dump = True
                 except KeyError:
                     onError("%sNo such xattr: %s" % (file_prefix, attr_name))
                     continue
 
                 if long_format:
-                    try:
-                        if '\0' in attr_value:
-                            raise NullsInString
-                        print("".join((file_prefix, "%s: " % (attr_name,), attr_value)))
-                    except (UnicodeDecodeError, NullsInString):
+                    if should_dump:
                         print("".join((file_prefix, "%s:" % (attr_name,))))
                         print(_dump(attr_value))
+                    else:
+                        print("".join((file_prefix, "%s: " % (attr_name,), attr_value)))
                 else:
                     if read:
-                        print("".join((file_prefix, attr_value)))
+                        if should_dump:
+                            if file_prefix:
+                                print(file_prefix)
+                            print(_dump(attr_value))
+                        else:
+                            print("".join((file_prefix, attr_value)))
                     else:
                         print("".join((file_prefix, attr_name)))
 
-    sys.exit(status)
+    return status
 
 if __name__ == "__main__":
-    main()
+    sys.exit(main(sys.argv))