static SV * streamproccallback = (SV*)NULL;

DWORD CALLBACK MyStreamProc(handle,buffer,length,user)
HSTREAM handle;
char *buffer;
int length;
DWORD user;
{
    if (streamproccallback == (SV*)NULL) return 0;
    dSP ;
    int ret;
    SV * shandle;
    SV * sbuffer;
    SV * slength;
    SV * suser;
    
    ENTER;
    SAVETMPS;
    shandle = sv_2mortal(newSViv(handle));
    sbuffer = sv_2mortal(newSVpv(buffer,length));
    slength = sv_2mortal(newSViv(length));
    suser   = sv_2mortal(newSViv(user));
    PUSHMARK(SP);
    XPUSHs(shandle);
    XPUSHs(sbuffer);
    XPUSHs(slength);
    XPUSHs(suser);
    PUTBACK;
    ret = call_sv(streamproccallback, G_SCALAR);
    buffer = SvPV(sbuffer,length);
    FREETMPS;
    LEAVE;
    return ret;
}