def read_etc_aliases():
    """Read /etc/aliases, and return as a dict."""
    aliases = {}
    with open('/etc/aliases') as f:
        for line in f:
            i_hash = line.find('#')
            if i_hash != -1:
                entry = line[:i_hash]
            else:
                entry = line
            if entry != '':
                toks = entry.split(':', 1)
                if len(toks) == 2:
                    user = toks[0].strip()
                    email = toks[1].strip()
                    if user != '' and email != '':
                        aliases[user] = email
    return aliases
