Function coap_payload_put_char

pub unsafe extern "C" fn coap_payload_put_char(
    pkt: *mut coap_pkt_t,
    c: c_char,
) -> ssize_t

@brief Add a single character to the payload data of the CoAP request

This function is used to add single characters to a CoAP payload data. It checks whether the character can be added to the buffer and ignores if the payload area is already exhausted.

@param[out] pkt pkt to add payload to @param[in] c character to write

@returns number of payload bytes added on success (always one) @returns < 0 on error