# zmq_ctx_get(3) Manual Page

## NAME

zmq_ctx_get - get context options

## SYNOPSIS

int zmq_ctx_get (void *context, int option_name);

## DESCRIPTION

The zmq_ctx_get() function shall return the option specified by the option_name argument.

The zmq_ctx_get() function accepts the following option names:

### ZMQ_IO_THREADS: Get number of I/O threads

The ZMQ_IO_THREADS argument returns the size of the ØMQ thread pool for this context.

### ZMQ_MAX_SOCKETS: Get maximum number of sockets

The ZMQ_MAX_SOCKETS argument returns the maximum number of sockets allowed for this context.

### ZMQ_IPV6: Set IPv6 option

The ZMQ_IPV6 argument returns the IPv6 option for the context.

## RETURN VALUE

The zmq_ctx_get() 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.

## EXAMPLE

Setting a limit on the number of sockets

    void *context = zmq_ctx_new ();
    zmq_ctx_set (context, ZMQ_MAX_SOCKETS, 256);
    int max_sockets = zmq_ctx_get (context, ZMQ_MAX_SOCKETS);
    assert (max_sockets == 256);

## SEE ALSO

zmq_ctx_set(3) zmq(7)

## AUTHORS

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