"""Superpowers which should be rarely used.
This library contains functions for importing python classes and
for running shell commands. Remember, with great power comes great
responsibility.
Authors
* Mirco Ravanelli 2020
"""
import logging
import subprocess
logger = logging.getLogger(__name__)
[docs]def run_shell(cmd):
r"""This function can be used to run a command in the bash shell.
Arguments
---------
cmd : str
Shell command to run.
Returns
-------
bytes
The captured standard output.
bytes
The captured standard error.
int
The returncode.
Raises
------
OSError
If returncode is not 0, i.e., command failed.
Example
-------
>>> out, err, code = run_shell("echo 'hello world'")
>>> out.decode("utf-8")
'hello world\n'
"""
# Executing the command
p = subprocess.Popen(
cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True
)
# Capturing standard output and error
(output, err) = p.communicate()
if p.returncode != 0:
raise OSError(err.decode("utf-8"))
# Adding information in the logger
msg = output.decode("utf-8") + "\n" + err.decode("utf-8")
logger.debug(msg)
return output, err, p.returncode