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72 lines
1.7 KiB
Plaintext
72 lines
1.7 KiB
Plaintext
zmq_msg_gets(3)
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===============
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NAME
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----
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zmq_msg_gets - get message metadata property
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SYNOPSIS
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--------
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*const char *zmq_msg_gets (zmq_msg_t '*message', const char *'property');*
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DESCRIPTION
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-----------
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The _zmq_msg_gets()_ function shall return the string value for the metadata
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property specified by the 'property' argument for the message pointed to by
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the 'message' argument. Both the 'property' argument and the 'value'
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shall be NULL-terminated UTF8-encoded strings.
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Metadata is defined on a per-connection basis during the ZeroMQ connection
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handshake as specified in <rfc.zeromq.org/spec:37>.
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The following ZMTP properties can be retrieved with the _zmq_msg_gets()_
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function:
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Socket-Type
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Identity
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Resource
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Other properties may be defined based on the underlying security, see ZAP
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auththenticated connection sample below.
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RETURN VALUE
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------------
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The _zmq_msg_gets()_ function shall return the string value for the property
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if successful. Otherwise it shall return NULL and set 'errno' to one of the
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values defined below. The caller shall not modify or free the returned value,
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which shall be owned by the message. The encoding of the property and value
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shall be UTF8.
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ERRORS
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------
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*EINVAL*::
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The requested _property_ is unknown.
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EXAMPLE
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-------
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.Getting the ZAP authenticated user id for a message:
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----
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zmq_msg_t msg;
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zmq_msg_init (&msg);
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rc = zmq_msg_recv (&msg, dealer, 0);
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assert (rc != -1);
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const char *user_id = zmq_msg_gets (&msg, "User-Id");
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zmq_msg_close (&msg);
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----
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SEE ALSO
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--------
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linkzmq:zmq[7]
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AUTHORS
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-------
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This page was written by the 0MQ community. To make a change please
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read the 0MQ Contribution Policy at <http://www.zeromq.org/docs:contributing>.
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