def exec_readlines_test_filter_stderr(self):
"""Test execReadlines and filter_stderr."""
# Test that stderr is normally included
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two" >&2
echo "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
# Test that filter stderr removes the middle line
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two" >&2
echo "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name], filter_stderr=True)
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
def exec_readlines_test_filter_stderr(self):
"""Test execReadlines and filter_stderr."""
# Test that stderr is normally included
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two" >&2
echo "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
# Test that filter stderr removes the middle line
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two" >&2
echo "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name], filter_stderr=True)
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
def test_exec_readlines_signals(self):
"""Test execReadlines and signal receipt."""
# ignored signal
old_HUP_handler = signal.signal(signal.SIGHUP, signal.SIG_IGN)
try:
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
kill -HUP $PPID
echo "two"
echo -n "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh",
[testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(StopIteration):
rl_iterator.__next__()
finally:
signal.signal(signal.SIGHUP, old_HUP_handler)
# caught signal
def _hup_handler(signum, frame):
pass
old_HUP_handler = signal.signal(signal.SIGHUP, _hup_handler)
try:
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
kill -HUP $PPID
echo "two"
echo -n "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh",
[testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(StopIteration):
rl_iterator.__next__()
finally:
signal.signal(signal.SIGHUP, old_HUP_handler)
def test_exec_readlines(self):
"""Test execReadlines."""
# test no lines are returned
assert list(util.execReadlines("true", [])) == []
# test some lines are returned
assert len(list(util.execReadlines("ls", ["--help"]))) > 0
# check that it always returns an iterator for both
# if there is some output and if there isn't any
assert hasattr(util.execReadlines("ls", ["--help"]), "__iter__")
assert hasattr(util.execReadlines("true", []), "__iter__")
def exec_readlines_test(self):
"""Test execReadlines."""
# test no lines are returned
self.assertEqual(list(util.execReadlines("true", [])), [])
# test some lines are returned
self.assertGreater(len(list(util.execReadlines("ls", ["--help"]))), 0)
# check that it always returns an iterator for both
# if there is some output and if there isn't any
self.assertTrue(hasattr(util.execReadlines("ls", ["--help"]), "__iter__"))
self.assertTrue(hasattr(util.execReadlines("true", []), "__iter__"))
def exec_readlines_test(self):
"""Test execReadlines."""
# test no lines are returned
self.assertEqual(list(util.execReadlines("true", [])), [])
# test some lines are returned
self.assertGreater(len(list(util.execReadlines("ls", ["--help"]))), 0)
# check that it always returns an iterator for both
# if there is some output and if there isn't any
self.assertTrue(hasattr(util.execReadlines("ls", ["--help"]), "__iter__"))
self.assertTrue(hasattr(util.execReadlines("true", []), "__iter__"))
def exec_readlines_test_signals(self):
"""Test execReadlines and signal receipt."""
# ignored signal
old_HUP_handler = signal.signal(signal.SIGHUP, signal.SIG_IGN)
try:
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
kill -HUP $PPID
echo "two"
echo -n "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
finally:
signal.signal(signal.SIGHUP, old_HUP_handler)
# caught signal
def _hup_handler(signum, frame):
pass
old_HUP_handler = signal.signal(signal.SIGHUP, _hup_handler)
try:
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
kill -HUP $PPID
echo "two"
echo -n "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
finally:
signal.signal(signal.SIGHUP, old_HUP_handler)
def exec_readlines_auto_kill_test(self):
"""Test execReadlines with reading only part of the output"""
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
# Output forever
while true; do
echo hey
done
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
# Save the process context
proc = rl_iterator._proc
# Read two lines worth
self.assertEqual(next(rl_iterator), "hey")
self.assertEqual(next(rl_iterator), "hey")
# Delete the iterator and wait for the process to be killed
del rl_iterator
proc.communicate()
# Check that the process is gone
self.assertIsNotNone(proc.poll())
def test_exec_readlines_auto_kill(self):
"""Test execReadlines with reading only part of the output"""
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
# Output forever
while true; do
echo hey
done
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
# Save the process context
proc = rl_iterator._proc
# Read two lines worth
assert next(rl_iterator) == "hey"
assert next(rl_iterator) == "hey"
# Delete the iterator and wait for the process to be killed
del rl_iterator
proc.communicate()
# Check that the process is gone
assert proc.poll() is not None
def get_doc_type(file_path):
try:
for line in execReadlines("oscap", ["info", file_path]):
if line.startswith("Document type:"):
_prefix, _sep, type_info = line.partition(":")
return type_info.strip()
except OSError:
# 'oscap info' exitted with a non-zero exit code -> unknown doc
# type
return None
def get_doc_type(file_path):
try:
for line in execReadlines("oscap", ["info", file_path]):
if line.startswith("Document type:"):
_prefix, _sep, type_info = line.partition(":")
return type_info.strip()
except OSError:
# 'oscap info' exitted with a non-zero exit code -> unknown doc
# type
return None
def journalctl_callback():
"""Callback to get logs from journalctl."""
# regex to filter log messages from anaconda's process (we have that in our
# logs)
anaconda_log_line = re.compile(r"\[%d\]:" % os.getpid())
ret = ""
for line in util.execReadlines("journalctl", ["-b"]):
if anaconda_log_line.search(line) is None:
# not an anaconda's message
ret += line + "\n"
return ret
def journalctl_callback():
"""Callback to get logs from journalctl."""
# regex to filter log messages from anaconda's process (we have that in our
# logs)
anaconda_log_line = re.compile(r"\[%d\]:" % os.getpid())
ret = ""
for line in util.execReadlines("journalctl", ["-b"]):
if anaconda_log_line.search(line) is None:
# not an anaconda's message
ret += line + "\n"
return ret
def test_exec_readlines_normal_output(self):
"""Test the output of execReadlines."""
# Test regular-looking output
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(StopIteration):
rl_iterator.__next__()
# Test output with no end of line
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo -n "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(StopIteration):
rl_iterator.__next__()
def run_grubby(args=None):
""" Run grubby and retrieve the kernel, initrd and boot arguments
:param list args: Arguments to pass to grubby.
:returns: kernel path, initrd path, root device, kernel cmdline args.
:rtype: namedtuple
:raises: some error on failure
The returned namedtuple contains the following attributes:
kernel, initrd, root, args
"""
boot_info_fields = ["kernel", "initrd", "root", "args"]
boot_info_class = namedtuple("BootInfo", boot_info_fields)
boot_info_args = {}
if not args:
args = ["--info", "DEFAULT"]
# Run grubby and fill in the boot_info with the first values seen, exit the
# loop when all of the needed values have been gathered.
try:
for line in execReadlines("grubby", args,
root=conf.target.system_root):
key, _sep, value = line.partition("=")
value = unquote(value)
if key in boot_info_fields:
boot_info_args[key] = value
boot_info_fields.remove(key)
if not boot_info_fields:
break
except OSError as e:
log.error("run_grubby failed: %s", e)
raise GrubbyInfoError(e)
if boot_info_fields:
raise GrubbyInfoError("Missing values: %s" %
", ".join(boot_info_fields))
# There could be multiple initrd images defined for a boot entry, but
# the kexec command line tool only supports passing a single initrd.
if "initrd" in boot_info_args:
boot_info_args["initrd"] = boot_info_args["initrd"].split(" ")[0]
boot_info = boot_info_class(**boot_info_args)
log.info("grubby boot info for (%s): %s", args, boot_info)
return boot_info
def get_locale_map_from_ostree(repo, ref):
"""Get a map of languages and locales from the given OSTree.
For example: {"en": ["en_US"]}
:param repo: the OSTree repository url
:param ref: the name of branch inside the repository
:return: a map of languages and locales
"""
# Fallback to just en_US in case of errors.
locale_map = {"en": ["en_US"]}
# Let's only handle local embedded repos for now. Anyway, it'd probably
# not be very common to only override ostreesetup through kickstart and
# still want the interactive installer. Though to be nice, let's handle
# that case.
if not repo.startswith("file://"):
log.info("ostree repo is not local; defaulting to en_US")
return
# Convert to regular UNIX path.
repo = repo[len("file://"):]
util.mkdirChain(os.path.join(repo, "tmp/usr/lib"))
rc = util.execWithRedirect("/usr/bin/ostree", [
"checkout", "--repo", repo, ref, "--subpath",
"/usr/lib/locale/locale-archive",
"%s/tmp/usr/lib/locale" % repo
])
if rc != 0:
log.error("failed to check out locale-archive; check program.log")
return
for line in util.execReadlines(
"/usr/bin/localedef",
["--prefix", os.path.join(repo, "tmp"), "--list-archive"]):
line = strip_codeset_and_modifier(line)
if '_' in line:
(lang, _territory) = line.split('_', 1)
else:
lang = line
if lang not in locale_map:
locale_map[lang] = [line]
else:
locale_map[lang].append(line)
# Nuke the checkout for good measure.
shutil.rmtree(os.path.join(repo, "tmp/usr"))
return locale_map
def exec_readlines_test_normal_output(self):
"""Test the output of execReadlines."""
# Test regular-looking output
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
# Test output with no end of line
with tempfile.NamedTemporaryFile(mode="w+t") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo -n "three"
exit 0
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(StopIteration, rl_iterator.__next__)
def get_locale_map_from_ostree(repo, ref):
"""Get a map of languages and locales from the given OSTree.
For example: {"en": ["en_US"]}
:param repo: the OSTree repository url
:param ref: the name of branch inside the repository
:return: a map of languages and locales
"""
# Fallback to just en_US in case of errors.
locale_map = {"en": ["en_US"]}
# Let's only handle local embedded repos for now. Anyway, it'd probably
# not be very common to only override ostreesetup through kickstart and
# still want the interactive installer. Though to be nice, let's handle
# that case.
if not repo.startswith("file://"):
log.info("ostree repo is not local; defaulting to en_US")
return
# Convert to regular UNIX path.
repo = repo[len("file://"):]
util.mkdirChain(os.path.join(repo, "tmp/usr/lib"))
rc = util.execWithRedirect("/usr/bin/ostree",
["checkout", "--repo", repo, ref,
"--subpath", "/usr/lib/locale/locale-archive",
"%s/tmp/usr/lib/locale" % repo])
if rc != 0:
log.error("failed to check out locale-archive; check program.log")
return
for line in util.execReadlines("/usr/bin/localedef",
["--prefix", os.path.join(repo, "tmp"),
"--list-archive"]):
line = strip_codeset_and_modifier(line)
if '_' in line:
(lang, _territory) = line.split('_', 1)
else:
lang = line
if lang not in locale_map:
locale_map[lang] = [line]
else:
locale_map[lang].append(line)
# Nuke the checkout for good measure.
shutil.rmtree(os.path.join(repo, "tmp/usr"))
return locale_map
def _initialize_localemap(self, ref, repo):
if self.localemap:
return
# fallback to just en_US in case of errors
self.localemap = {"en": ["en_US"]}
# Let's only handle local embedded repos for now. Anyway, it'd probably
# not be very common to only override ostreesetup through kickstart and
# still want the interactive installer. Though to be nice, let's handle
# that case.
if not repo.startswith("file://"):
log.info("ostree repo is not local; defaulting to en_US")
return
# convert to regular UNIX path
repo = repo[len("file://"):]
util.mkdirChain(os.path.join(repo, "tmp/usr/lib"))
rc = util.execWithRedirect("/usr/bin/ostree", [
"checkout", "--repo", repo, ref, "--subpath",
"/usr/lib/locale/locale-archive",
"%s/tmp/usr/lib/locale" % repo
])
if rc != 0:
log.error("failed to check out locale-archive; check program.log")
return
for line in util.execReadlines(
"/usr/bin/localedef",
["--prefix",
os.path.join(repo, "tmp"), "--list-archive"]):
line = self._strip_codeset_and_modifier(line)
if '_' in line:
(lang, _territory) = line.split('_', 1)
else:
lang = line
if lang not in self.localemap:
self.localemap[lang] = [line]
else:
self.localemap[lang].append(line)
# nuke the checkout for good measure
shutil.rmtree(os.path.join(repo, "tmp/usr"))
def run_grubby(args=None):
""" Run grubby and retrieve the kernel, initrd and boot arguments
:param list args: Arguments to pass to grubby.
:returns: kernel path, initrd path, root device, kernel cmdline args.
:rtype: namedtuple
:raises: some error on failure
The returned namedtuple contains the following attributes:
kernel, initrd, root, args
"""
boot_info_fields = ["kernel", "initrd", "root", "args"]
boot_info_class = namedtuple("BootInfo", boot_info_fields)
boot_info_args = {}
if not args:
args = ["--info", "DEFAULT"]
# Run grubby and fill in the boot_info with the first values seen, exit the
# loop when all of the needed values have been gathered.
try:
for line in execReadlines("grubby", args, root=getSysroot()):
key, _sep, value = line.partition("=")
value = unquote(value)
if key in boot_info_fields:
boot_info_args[key] = value
boot_info_fields.remove(key)
if not boot_info_fields:
break
except OSError as e:
log.error("run_grubby failed: %s", e)
raise GrubbyInfoError(e)
if boot_info_fields:
raise GrubbyInfoError("Missing values: %s" % ", ".join(boot_info_fields))
boot_info = boot_info_class(**boot_info_args)
log.info("grubby boot info for (%s): %s", args, boot_info)
return boot_info
def run_grubby(args=None):
""" Run grubby and retrieve the kernel, initrd and boot arguments
:param list args: Arguments to pass to grubby.
:returns: kernel path, initrd path, root device, kernel cmdline args.
:rtype: namedtuple
:raises: some error on failure
The returned namedtuple contains the following attributes:
kernel, initrd, root, args
"""
boot_info = _BootInfo()
attrs = list(_BootInfo._fields)
if not args:
args = ["--info", "DEFAULT"]
# Run grubby and fill in the boot_info with the first values seen, exit the
# loop when all of the needed values have been gathered.
try:
for line in execReadlines("grubby", args, root=getSysroot()):
key, _sep, value = line.partition("=")
value = unquote(value)
if key in attrs:
setattr(boot_info, key, value)
attrs.remove(key)
if not attrs:
break
except OSError as e:
log.error("run_grubby failed: %s", e)
raise GrubbyInfoError(e)
if len(attrs) > 0:
raise GrubbyInfoError("Missing values: %s" % ", ".join(attrs))
log.info("grubby boot info for (%s): %s", args, boot_info)
return boot_info
def get_doc_type(file_path):
content_type = "unknown"
try:
for line in execReadlines("oscap", ["info", file_path]):
if line.startswith("Document type:"):
_prefix, _sep, type_info = line.partition(":")
content_type = type_info.strip()
break
except OSError:
# 'oscap info' exitted with a non-zero exit code -> unknown doc
# type
pass
except UnicodeDecodeError:
# 'oscap info' supplied weird output, which happens when it tries
# to explain why it can't examine e.g. a JPG.
pass
except Exception as e:
log.warning(
f"OSCAP addon: Unexpected error when looking at {file_path}: {str(e)}"
)
log.info("OSCAP addon: Identified {file_path} as {content_type}".format(
file_path=file_path, content_type=content_type))
return content_type
def test_exec_readlines_exits(self):
"""Test execReadlines in different child exit situations."""
# Tests that exit on signal will raise OSError once output
# has been consumed, otherwise the test will exit normally.
# Test a normal, non-0 exit
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo "three"
exit 1
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(OSError):
rl_iterator.__next__()
# Test exit on signal
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo "three"
kill -TERM $$
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(OSError):
rl_iterator.__next__()
# Repeat the above two tests, but exit before a final newline
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo -n "three"
exit 1
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(OSError):
rl_iterator.__next__()
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo -n "three"
kill -TERM $$
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
assert next(rl_iterator) == "one"
assert next(rl_iterator) == "two"
assert next(rl_iterator) == "three"
with pytest.raises(OSError):
rl_iterator.__next__()
def exec_readlines_test_exits(self):
"""Test execReadlines in different child exit situations."""
# Tests that exit on signal will raise OSError once output
# has been consumed, otherwise the test will exit normally.
# Test a normal, non-0 exit
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo "three"
exit 1
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(OSError, rl_iterator.__next__)
# Test exit on signal
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo "three"
kill -TERM $$
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(OSError, rl_iterator.__next__)
# Repeat the above two tests, but exit before a final newline
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo -n "three"
exit 1
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(OSError, rl_iterator.__next__)
with tempfile.NamedTemporaryFile(mode="wt") as testscript:
testscript.write("""#!/bin/sh
echo "one"
echo "two"
echo -n "three"
kill -TERM $$
""")
testscript.flush()
with timer(5):
rl_iterator = util.execReadlines("/bin/sh", [testscript.name])
self.assertEqual(next(rl_iterator), "one")
self.assertEqual(next(rl_iterator), "two")
self.assertEqual(next(rl_iterator), "three")
self.assertRaises(OSError, rl_iterator.__next__)
