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Python subprocess with timeout.
import subprocess
import signal
class Signal(Exception):
"""
This exception is raise by the signal handler.
"""
pass
class Timeout(Exception):
"""
This exception is raised when the command exceeds the defined timeout
duration and the command is killed.
"""
def __init__(self, cmd, timeout):
self.cmd = cmd
self.timeout = timeout
def __str__(self):
return "Command '%s' timed out after %d second(s)." % \
(self.cmd, self.timeout)
class Retcode(Exception):
"""
This exception is raise when a command exits with a non-zero exit status.
"""
def __init__(self, cmd, retcode, output=None):
self.cmd = cmd
self.retcode = retcode
self.output = output
def __str__(self):
return "Command '%s' returned non-zero exit status %d" % \
(self.cmd, self.returncode)
def alarm_handler(signum, frame):
raise Signal
def execute(cmd, timeout=None):
"""
Execute a command in the default shell. If a timeout is defined the command
will be killed if the timeout is exceeded and an exception will be raised.
Inputs:
cmd (str): Command to execute
timeout (int): Command timeout in seconds
Outputs:
output (str): STDOUT/STDERR
"""
# Define the timeout signal
if timeout:
signal.signal(signal.SIGALRM, alarm_handler)
signal.alarm(timeout)
try:
# Execute the command and wait for the subprocess to terminate
# STDERR is redirected to STDOUT
phandle = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE,
stderr=subprocess.STDOUT)
# Read the stdout/sterr buffers and retcode
output, _ = phandle.communicate()
retcode = phandle.poll()
except Signal:
# Kill the running process
phandle.kill()
raise Timeout(cmd=cmd, timeout=timeout)
except:
raise
else:
# Possible race condition where alarm isn't disabled in time
signal.alarm(0)
# Raise an exception if the command exited with non-zero exit status
if retcode:
raise Retcode(cmd, retcode, output=output)
return output
@IceLuck

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@IceLuck IceLuck commented Aug 22, 2017

Hi Dear
How to modify this code to use in milliseconds?
Tks
Luciano

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