xs_zmq(7)

# xs_zmq(7) Manual Page

## NAME

xs_zmq - Crossroads I/O ZeroMQ compatibility library

## SYNOPSIS

#include <zmq.h>

cc [flags] files -lzmq [libraries]

## DESCRIPTION

This libzmq compatibility library is provided by the Crossroads I/O project as a transitional drop-in replacement for existing applications and language bindings written for the ZeroMQ library.

The intent is to ease transition of existing ZeroMQ applications and language bindings to Crossroads I/O, thus this feature will not be maintained indefinitely and developers are strongly encouraged to migrate their applications to native libxs interfaces.

libzmq interfaces provided emulate those provided by ZeroMQ release 2.1.11, and binary compatibility is provided for ABI version 1.0.0.

Existing applications can use these interfaces as a drop-in replacement for the ZeroMQ-provided libzmq by installing the Crossroads version of this library in its place. Applications can also be recompiled against this library with no code or build system changes.

Important | The libzmq compatibility library is an optional component of Crossroads I/O, and is only built and installed if your copy of the Crossroads library was configured with `--enable-libzmq` at build time.

## CONSTANTS

All constants defined by the ZeroMQ 2.1.11 version of <zmq.h> are also defined in the Crossroads version.

## INTERFACES

### Context

    void *zmq_init (int io_threads);
    int zmq_term (void *context);

### Sockets

    void *zmq_socket (void *context, int type);
    int zmq_close (void *socket);
    int zmq_connect (void *socket, const char *endpoint);
    int zmq_bind (void *socket, const char *endpoint);
    int zmq_setsockopt (void *socket, int option_name, const void *option_value, size_t option_len);
    int zmq_getsockopt (void *socket, int option_name, void *option_value, size_t *option_len);
    int zmq_poll (zmq_pollitem_t *items, int nitems, long timeout);

### Messages

    int zmq_msg_init (zmq_msg_t *msg);
    int zmq_msg_init_size (zmq_msg_t *msg, size_t size);
    int zmq_msg_init_data (zmq_msg_t *msg, void *data, size_t size, zmq_free_fn *ffn, void *hint);
    size_t zmq_msg_size (zmq_msg_t *msg);
    void *zmq_msg_data (zmq_msg_t *msg);
    int zmq_msg_close (zmq_msg_t *msg);
    int zmq_msg_copy (zmq_msg_t *dest, zmq_msg_t *src);
    int zmq_msg_move (zmq_msg_t *dest, zmq_msg_t *src);

### Sending and receiving

    int zmq_send (void *socket, zmq_msg_t *msg, int flags);
    int zmq_recv (void *socket, zmq_msg_t *msg, int flags);

### Devices

    int zmq_device (int device, const void *frontend, const void *backend);

### Error handling

    int zmq_errno (void);
    const char *zmq_strerror (int errnum);

### Version detection

    void zmq_version (int *major, int *minor, int *patch);

Note | The version numbers returned by this function are the emulated ZeroMQ API version, i.e. 2.1.11.

## COPYING

Free use of Crossroads library is granted under the terms of the GNU Lesser General Public License (LGPL). For details see the files `COPYING` and `COPYING.LESSER` included with the Crossroads distribution.

## SEE ALSO

xs(7)

## AUTHORS

The Crossroads documentation was written by Martin Sustrik <sustrik@250bpm.com> and Martin Lucina <martin@lucina.net>.