SYNOPSIS
        #include <erq.h>

        int send_erq(int request, bytes|int * data, closure callback)

DESCRIPTION
        A request of given type (<request>, default is 0), equipped
        with the given <data>, is sent to the erq. If <callback> is
        set to a closure, it will be called when the response from the
        erq (a status code) arrives, if the response carries enough data to
        work on.

        <request> can be one of the request codes defined in <erq.h>.
        The binary flag ERQ_CB_STRING defines whether the <callback>
        closure expects the returned data packed into an array of
        integers or as a string.

        <data> may be a byte sequence, or an array of integers which are
        then interpreted as bytes.

        <callback>, if set, is a closure of either these forms:

          !ERQ_CB_STRING: void <closure>(int *response_data, int len)
           ERQ_CB_STRING: void <closure>(string response_data)

        The result returned from the efun is 0 on failure to send the
        data, or non-zero on a successful send.

        The function causes a privilege violation "erq".

HISTORY
        Introduced in 3.2.1@61.
        Made a privileged function in 3.2.1@84
        LDMud 3.3.318 introduced the ERQ_CB_STRING flag.

SEE ALSO
        attach_erq_demon(E), erq(C)