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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def _linux_nqn():
    '''
    Return NVMe NQN from a Linux host.
    '''
    ret = []

    initiator = '/etc/nvme/hostnqn'
    try:
        with salt.utils.files.fopen(initiator, 'r') as _nvme:
            for line in _nvme:
                line = line.strip()
                if line.startswith('nqn.'):
                    ret.append(line)
    except IOError as ex:
        if ex.errno != errno.ENOENT:
            log.debug("Error while accessing '%s': %s", initiator, ex)

    return ret