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

AUTHORS

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