pstatus: Status code helper utility

pstatus is can be used to extract meaning from process status codes as returned by os.system, os.wait, os.waitpid, as well as subprocess.call, subprocess.CalledProcessError.returncode, subprocess.Popen.call, subprocess.Popen.wait, and subprocess.Popen.returncode.

It exports one function split which extracts an exit code, a signal number, a flag indicating whether or not the process left a core dump behind.

class pstatus.Status

This object may be accessed as either a tuple of (exit, signal, core) or via the attributes exit, signal, and core. Additionally another attribute ok is defined which indicates whether or not the process exited successfully.

ok

Returns whether or not the process exited successfully

pstatus.split(status, subprocess=False)

Split an exit status code as returned by os.system, os.wait, or os.waitpid, returning a tuple which includes the processes exit code, the signal responsible for the processes termination, and whether or not the process left a core dump behind. If there was no exit code then the first value will be None, and if there was no signal, then the second value will be None.

Optionally, and perhaps with less utility, if a second flag is passed and set to True, will split a returncode as returned by the subprocess module. In this instance the core part of the returned 3-tuple will always be None, because that information is unavailable.

For example, with os.system:

>>> split(os.system('true'))
Status(exit=0, signal=None, core=False)
>>> split(os.system('false'))
Status(exit=1, signal=None, core=False)

Using os.spawnlp and os.kill to demonstrate extraction of signals:

>>> pid = os.spawnlp(os.P_NOWAIT, 'sleep', 'sleep', '100')
>>> os.kill(pid, 15)
>>> _, code = os.waitpid(pid, 0)
>>> split(code)
Status(exit=None, signal=15, core=False)

And now with subprocess.call:

>>> import subprocess
>>> split(subprocess.call(['true']), subprocess=True)
Status(exit=0, signal=None, core=None)
>>> split(subprocess.call(['false']), subprocess=True)
Status(exit=1, signal=None, core=None)

Using subprocess.Popen and subprocess.Popen.kill to extract signals:

>>> p = subprocess.Popen(['sleep', '100'])
>>> p.terminate()
>>> split(p.wait(), subprocess=True)
Status(exit=None, signal=15, core=None)

Parameters:

• status (int) – status code to split
• subprocess (bool) – flag indicating supplied status is a subprocess returncode

Returns:

3-tuple (exit, signal, core)

Return type:

3-tuple

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