import subprocess
import shlex

def run_command(command, expected_retcodes = 0, stdin = None):
    """run a command and raise an exception if retcode not in expected_retcode"""

    # we want expected_retcode to be a tuple but will manage integers
    if type(expected_retcodes) == type(0):
        expected_retcodes = (expected_retcodes,)

    # we want the command to be a list, but accomodate when given a string
    cmd = command
    if type(cmd) == type('string'):
        cmd = shlex.split(command)
    print cmd
    proc = subprocess.Popen(cmd,
                            stdin  = stdin,
                            stdout = subprocess.PIPE,
                            stderr = subprocess.PIPE)

    out, err = proc.communicate()

    if proc.returncode not in expected_retcodes:
        # when nothing gets to stderr, add stdout to Detail
        if err.strip() == '':
            err = out

        mesg  = 'Error [%d]: %s' % (proc.returncode, command)
        mesg += '\nDetail: %s' % err
        raise Exception, mesg

    return proc.returncode, out, err