def _cmdline(obj: drgn.Object) -> str:
try:
s = " ".join(map(lambda s: s.decode("utf-8"), cmdline(obj)))
#
# The command line for a given thread can be obnoxiously long,
# so (by default) we limit it to 50 characters here. This helps
# preserve the readability of the command's output, but comes at
# the cost of not always showing the full command line of a
# thread.
#
return shorten(s, width=50)
except drgn.FaultError:
#
# The command line information is contained in the user address
# space of each thread, rather than in the kernel's address
# space. Thus, often, it may not be possible to retreive the
# thread's command line; e.g. when reading from a core dump.
#
return ""
def test_cmdline(self):
with open("/proc/self/cmdline", "rb") as f:
proc_cmdline = f.read().split(b"\0")[:-1]
task = find_task(self.prog, os.getpid())
self.assertEqual(cmdline(task), proc_cmdline)