ZMQ_CTX_GET_EXT(3)                0MQ Manual                ZMQ_CTX_GET_EXT(3)

NAME
       zmq_ctx_get_ext - get extended context options

SYNOPSIS
       int zmq_ctx_get_ext (void *context, int option_name, void
       *option_value, size_t *option_len);

DESCRIPTION
       The zmq_ctx_get() function shall retrieve the value for the option
       specified by the option_name argument and store it in the buffer
       pointed to by the option_value argument. The option_len argument is the
       size in bytes of the buffer pointed to by option_value; upon successful
       completion zmq_ctx_get_ext() shall modify the option_len argument to
       indicate the actual size of the option value stored in the buffer.

       The zmq_ctx_get_ext() function accepts all the option names accepted by
       zmq_ctx_get(). Options that make most sense to retrieve using
       zmq_ctx_get_ext() instead of zmq_ctx_get() are:

   ZMQ_THREAD_NAME_PREFIX: Get name prefix for I/O threads
       The ZMQ_THREAD_NAME_PREFIX argument gets the string prefix of each
       thread created for the internal context's thread pool.

       Option value type   character string
       Option value unit   N/A
       Default value       empty string


RETURN VALUE
       The zmq_ctx_get_ext() function returns a value of 0 or greater if
       successful. Otherwise it returns -1 and sets errno to one of the values
       defined below.

ERRORS
       EINVAL
           The requested option option_name is unknown.

       EFAULT
           The provided context is invalid.

EXAMPLE
       Setting a prefix on internal ZMQ thread names:.

           void *context = zmq_ctx_new ();
           const char prefix[] = "MyApp";
           size_t prefixLen = sizeof(prefix);
           zmq_ctx_set (context, ZMQ_THREAD_NAME_PREFIX, &prefix, &prefixLen);

           char buff[256];
           size_t buffLen = sizeof(buff);
           int rc = zmq_ctx_get (context, ZMQ_THREAD_NAME_PREFIX, &buff, &buffLen);
           assert (rc == 0);
           assert (buffLen == prefixLen);


SEE ALSO
       zmq_ctx_get(3) zmq(7)

AUTHORS
       This page was written by the 0MQ community. To make a change please
       read the 0MQ Contribution Policy at
       http://www.zeromq.org/docs:contributing.

0MQ 4.3.5                         02/15/2026                ZMQ_CTX_GET_EXT(3)