## nng_msg_append Append to message body. ### Synopsis ```c #include int nng_msg_append(nng_msg *msg, const void *val, size_t size); int nng_msg_append_u16(nng_msg *msg, uint16_t val16); int nng_msg_append_u32(nng_msg *msg, uint32_t val32); int nng_msg_append_u64(nng_msg *msg, uint64_t val64); ``` ### Description These functions append data to the end of the body of message _msg_, reallocating it if necessary. The `nng_msg_append` function appends _size_ bytes, copying them from _val_. The remaining functions append the value specified (such as _val32_) in network-byte order (big-endian). ### Return Values These functions return 0 on success, and non-zero otherwise. ### Errors [horizontal] `NNG_ENOMEM`:: Insufficient free memory exists. ### See Also xref:nng_msg_alloc.adoc[nng_msg_alloc], xref:nng_msg_body.adoc[nng_msg_body], xref:nng_msg_chop.adoc[nng_msg_chop], xref:nng_msg_free.adoc[nng_msg_free], xref:nng_msg_insert.adoc[nng_msg_insert], xref:nng_msg_len.adoc[nng_msg_len], xref:nng_msg_realloc.adoc[nng_msg_realloc], xref:nng_msg_trim.adoc[nng_msg_trim],