RunCmd is ia Python module which allows you to run a command with a timeout option.

RunCmd can be considered a substitute for a common subprocess usage pattern:

p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
ret, out = p.communicate()

But with additional option to set a timeout for the command. Like subprocess.Popen, this is a blocking call, and will wait for either the command to complete or a timeout to occur.

RunCmd is not meant to be a replacement for subprocess module itself.

• supports Python 2.6x and Python 2.7x.
• runs under both Windows and Linux. It should run under OSX.

Just copy the the runcmd.py file into your directory. Or use the setup.py if you wish to install it.

RunCmd has two methods: RunCmd.run() and RunCmd.run_fd().

RunCmd.run() reads the output into am internal buffer and return the output to the user as a tuple of (returncode, output).

from runcmd import RunCmd

cmd = RunCmd()
#run the command using the shell and a timeout of 5 seconds.
returncode, out = cmd.run('echo Hello World', shell=True, timeout=5)
print "returncode is %d. Output is %s" % (returncode, out)

RunCmd.run() is not suitable for handling processes with large volume of data as it attempts to buffer the entire output. Instead, useRunCmd.run_fd(), which allows a user to pass in a file object where the output will be written into.

from runcmd import RunCmd

with open('tmp.txt', 'wb') as f:
    cmd = RunCmd()
    # run the command using the shell and a timeout of 5 seconds.
    cmd.run_fd('echo Hello World', f, shell=True, timeout=5)

print "returncode is %d. Output is %s" % (cmd.returncode, open('tmp.txt', 'rb').read())

RunCmd.run_fd can handle large volume of data; there is a utility script under ./util/generate_output.py which can simulate output of different sizes. Try simulating a 1GB output :-).

RunCmd has a CLI as well. For example,

python runcmd.py --cmd="echo Hello World" --shell --timeout=5

RunCmd has a unittests script. See ./tests/test_runcmd.py.

RunCmd is released under the MIT license. See LICENSE.txt