ZMQ_MSG_GETS(3) 0MQ Manual ZMQ_MSG_GETS(3)NAMEzmq_msg_gets - get message metadata property
SYNOPSIS
const char *zmq_msg_gets (zmq_msg_t *message, const char *property);
DESCRIPTION
The zmq_msg_gets() function shall return the string value for the
metadata property specified by the property argument for the message
pointed to by the message argument. Both the property argument and the
value shall be NULL-terminated UTF8-encoded strings.
Metadata is defined on a per-connection basis during the ZeroMQ
connection handshake as specified in <rfc.zeromq.org/spec:37>.
The following ZMTP properties can be retrieved with the zmq_msg_gets()
function:
Socket-Type
Identity
Resource
Additionally, when available for the underlying transport, the
Peer-Address property will return the IP address of the remote endpoint
as returned by getnameinfo(2).
Other properties may be defined based on the underlying security
mechanism, see ZAP authenticated connection sample below.
RETURN VALUE
The zmq_msg_gets() function shall return the string value for the
property if successful. Otherwise it shall return NULL and set errno to
one of the values defined below. The caller shall not modify or free
the returned value, which shall be owned by the message. The encoding
of the property and value shall be UTF8.
ERRORS
EINVAL
The requested property is unknown.
EXAMPLE
Getting the ZAP authenticated user id for a message:.
zmq_msg_t msg;
zmq_msg_init (&msg);
rc = zmq_msg_recv (&msg, dealer, 0);
assert (rc != -1);
const char *user_id = zmq_msg_gets (&msg, "User-Id");
zmq_msg_close (&msg);
SEE ALSOzmq(7)AUTHORS
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0MQ 4.1.3 08/17/2015 ZMQ_MSG_GETS(3)
