processes

Note that this function will consume stdout as soon as it’s available, so that you don’t need to worry about the buffer overflowing and such.

satella.processes.call_and_return_stdout(args: Union[str, List[str]], timeout: Union[str, int, None] = None, encoding: Optional[str] = None, expected_return_code: Optional[int] = None, **kwargs) → Union[bytes, str]

Call a process and return it’s stdout.

Everything in kwargs will be passed to subprocess.Popen

A bytes object will be returned if encoding is not defined, else stdout will be decoded according to specified encoding.

Deprecated since version Use: subprocess.check_output instead.

Parameters:

• args – arguments to run the program with. Can be either a string or a list of strings.
• timeout – amount of seconds to wait for the process result. If process does not complete within this time, it will be sent a SIGKILL. Can be also a time string. If left at default, ie. None, timeout won’t be considered at all.
• encoding – encoding with which to decode stdout. If none is passed, it will be returned as a bytes object
• expected_return_code – an expected return code of this process. 0 is the default. If process returns anything else, ProcessFailed will be raise. If left default (None) return code won’t be checked at all

Raises:

• ProcessFailed – process’ result code was different from the requested
• TimeoutError – timeout was specified and the process didn’t complete

This is a subprocess helper:

satella.processes.read_nowait(process: subprocess.Popen, output_list: List[str])

This spawns a thread to read given process’ stdout and append it to a list, in order to prevent buffer filling up completely.

To retrieve entire stdout after process finishes do

>>> ''.join(list)

This thread will terminate automatically after the process closes it’s stdout or finishes.