cparam
void *cparam;
n = bt_devsend(s, req->opcode, req->cparam, req->clen);
mip->mi_version = cparam(NULL, hfield(MIME_HDR_VERSION, mp), 0);
mip->mi_encoding = cparam(NULL, hfield(MIME_HDR_ENCODING, mp), 1);
mip->mi_type = mime_type = cparam(NULL, mime_type_field, 1);
mip->mi_boundary = cparam("boundary", mime_type_field, 0);
mip->mi_charset = cparam("charset", mime_type_field, 1);
mip->mi_disposition = cparam(NULL, mime_disposition_field, 1);
filename = cparam("name", mime_type_field, 0);
if ((cp = cparam("filename", mime_disposition_field, 0)) != NULL)
req.cparam = cbuf;