def delete_file_ios(ssh_conn, dest_file_system, dest_file):
    """
        Delete a remote file for a Cisco IOS device:

        cisco1#del flash:/useless_file.cfg
        Delete filename [useless_file.cfg]?
        Delete flash:/useless_file.cfg? [confirm]y

    delete disk0:/test9.txt
    Mon Aug 31 17:56:15.008 UTC
    Delete disk0:/test9.txt[confirm]
    """
    if not dest_file_system:
        raise ValueError("Invalid file system specified")
    if not dest_file:
        raise ValueError("Invalid dest file specified")

    full_file_name = f"{dest_file_system}/{dest_file}"

    cmd = f"delete {full_file_name}"
    output = ssh_conn.send_command(cmd, expect_string=r"Delete filename")
    if "Delete" in output and dest_file in output:
        output += ssh_conn.send_command("\n", expect_string=r"confirm")
        output += ssh_conn.send_command("y", expect_string=r"#")
        return output

    raise ValueError("An error happened deleting file on Cisco IOS")