git clone git://github.com/zeromq/czmq.git
cd czmq
sh autogen.sh
./configure
make all
sudo make install
sudo ldconfig

./configure --with-libzmq=/usr/local

make check

gcc -lczmq -lzmq myapp.c -o myapp

//  Create new context, returns context object, replaces zmq_init
CZMQ_EXPORT zctx_t *
    zctx_new (void);

//  Destroy context and all sockets in it, replaces zmq_term
CZMQ_EXPORT void
    zctx_destroy (zctx_t **self_p);

//  Raise default I/O threads from 1, for crazy heavy applications
CZMQ_EXPORT void
    zctx_set_iothreads (zctx_t *self, int iothreads);

//  Set msecs to flush sockets when closing them
CZMQ_EXPORT void
    zctx_set_linger (zctx_t *self, int linger);

//  Set HWM value. This is used in zthread_fork
CZMQ_EXPORT void
    zctx_set_hwm (zctx_t *self, int hwm);

//  Get HWM value. This is used in zthread_fork
int
    zctx_hwm (zctx_t *self);

//  Return low-level ØMQ context object, will be NULL before first socket
//  is created. Use with care.
CZMQ_EXPORT void *
    zctx_underlying (zctx_t *self);

//  Self test of this class
int
    zctx_test (Bool verbose);

//  Global signal indicator, TRUE when user presses Ctrl-C or the process
//  gets a SIGTERM signal.
CZMQ_EXPORT extern volatile int zctx_interrupted;

//  This port range is defined by IANA for dynamic or private ports
//  We use this when choosing a port for dynamic binding.
#define ZSOCKET_DYNFROM     0xc000
#define ZSOCKET_DYNTO       0xffff

//  Create a new socket within our CZMQ context, replaces zmq_socket.
//  Use this to get automatic management of the socket at shutdown.
//  Note: SUB sockets do not automatically subscribe to everything; you
//  must set filters explicitly.
CZMQ_EXPORT void *
    zsocket_new (zctx_t *self, int type);

//  Destroy a socket within our CZMQ context, replaces zmq_close.
CZMQ_EXPORT void
    zsocket_destroy (zctx_t *self, void *socket);

//  Bind a socket to a formatted endpoint. If the port is specified as
//  '*', binds to any free port from ZSOCKET_DYNFROM to ZSOCKET_DYNTO
//  and returns the actual port number used. Otherwise asserts that the
//  bind succeeded with the specified port number. Always returns the
//  port number if successful.
CZMQ_EXPORT int
    zsocket_bind (void *socket, const char *format, ...);

//  Connect a socket to a formatted endpoint
//  Returns 0 if OK, -1 if the endpoint was invalid.
CZMQ_EXPORT int
    zsocket_connect (void *socket, const char *format, ...);

//  Disonnect a socket from a formatted endpoint
//  Returns 0 if OK, -1 if the endpoint was invalid or the function
//  isn't supported.
CZMQ_EXPORT int
    zsocket_disconnect (void *socket, const char *format, ...);

//  Poll for input events on the socket. Returns TRUE if there is input
//  ready on the socket, else FALSE.
CZMQ_EXPORT Bool
    zsocket_poll (void *socket, int msecs);
    
//  Returns socket type as printable constant string
CZMQ_EXPORT char *
    zsocket_type_str (void *socket);

//  Self test of this class
int
    zsocket_test (Bool verbose);

#if (ZMQ_VERSION_MAJOR == 2)
//  Get socket options
CZMQ_EXPORT int zsocket_hwm (void *zocket);
CZMQ_EXPORT int zsocket_swap (void *zocket);
CZMQ_EXPORT int zsocket_affinity (void *zocket);
//  Returns freshly allocated string, free when done
CZMQ_EXPORT char * zsocket_identity (void *zocket);
CZMQ_EXPORT int zsocket_rate (void *zocket);
CZMQ_EXPORT int zsocket_recovery_ivl (void *zocket);
CZMQ_EXPORT int zsocket_recovery_ivl_msec (void *zocket);
CZMQ_EXPORT int zsocket_mcast_loop (void *zocket);
#   if (ZMQ_VERSION_MINOR == 2)
CZMQ_EXPORT int zsocket_rcvtimeo (void *zocket);
#   endif
#   if (ZMQ_VERSION_MINOR == 2)
CZMQ_EXPORT int zsocket_sndtimeo (void *zocket);
#   endif
CZMQ_EXPORT int zsocket_sndbuf (void *zocket);
CZMQ_EXPORT int zsocket_rcvbuf (void *zocket);
CZMQ_EXPORT int zsocket_linger (void *zocket);
CZMQ_EXPORT int zsocket_reconnect_ivl (void *zocket);
CZMQ_EXPORT int zsocket_reconnect_ivl_max (void *zocket);
CZMQ_EXPORT int zsocket_backlog (void *zocket);
CZMQ_EXPORT int zsocket_type (void *zocket);
CZMQ_EXPORT int zsocket_rcvmore (void *zocket);
CZMQ_EXPORT int zsocket_fd (void *zocket);
CZMQ_EXPORT int zsocket_events (void *zocket);

//  Set socket options
CZMQ_EXPORT void zsocket_set_hwm (void *zocket, int hwm);
CZMQ_EXPORT void zsocket_set_swap (void *zocket, int swap);
CZMQ_EXPORT void zsocket_set_affinity (void *zocket, int affinity);
CZMQ_EXPORT void zsocket_set_identity (void *zocket, char * identity);
CZMQ_EXPORT void zsocket_set_rate (void *zocket, int rate);
CZMQ_EXPORT void zsocket_set_recovery_ivl (void *zocket, int recovery_ivl);
CZMQ_EXPORT void zsocket_set_recovery_ivl_msec (void *zocket, int recovery_ivl_msec);
CZMQ_EXPORT void zsocket_set_mcast_loop (void *zocket, int mcast_loop);
#   if (ZMQ_VERSION_MINOR == 2)
CZMQ_EXPORT void zsocket_set_rcvtimeo (void *zocket, int rcvtimeo);
#   endif
#   if (ZMQ_VERSION_MINOR == 2)
CZMQ_EXPORT void zsocket_set_sndtimeo (void *zocket, int sndtimeo);
#   endif
CZMQ_EXPORT void zsocket_set_sndbuf (void *zocket, int sndbuf);
CZMQ_EXPORT void zsocket_set_rcvbuf (void *zocket, int rcvbuf);
CZMQ_EXPORT void zsocket_set_linger (void *zocket, int linger);
CZMQ_EXPORT void zsocket_set_reconnect_ivl (void *zocket, int reconnect_ivl);
CZMQ_EXPORT void zsocket_set_reconnect_ivl_max (void *zocket, int reconnect_ivl_max);
CZMQ_EXPORT void zsocket_set_backlog (void *zocket, int backlog);
CZMQ_EXPORT void zsocket_set_subscribe (void *zocket, char * subscribe);
CZMQ_EXPORT void zsocket_set_unsubscribe (void *zocket, char * unsubscribe);
#endif

#if (ZMQ_VERSION_MAJOR == 3)
//  Get socket options
CZMQ_EXPORT int zsocket_type (void *zocket);
CZMQ_EXPORT int zsocket_sndhwm (void *zocket);
CZMQ_EXPORT int zsocket_rcvhwm (void *zocket);
CZMQ_EXPORT int zsocket_affinity (void *zocket);
//  Returns freshly allocated string, free when done
CZMQ_EXPORT char * zsocket_identity (void *zocket);
CZMQ_EXPORT int zsocket_rate (void *zocket);
CZMQ_EXPORT int zsocket_recovery_ivl (void *zocket);
CZMQ_EXPORT int zsocket_sndbuf (void *zocket);
CZMQ_EXPORT int zsocket_rcvbuf (void *zocket);
CZMQ_EXPORT int zsocket_linger (void *zocket);
CZMQ_EXPORT int zsocket_reconnect_ivl (void *zocket);
CZMQ_EXPORT int zsocket_reconnect_ivl_max (void *zocket);
CZMQ_EXPORT int zsocket_backlog (void *zocket);
CZMQ_EXPORT int zsocket_maxmsgsize (void *zocket);
CZMQ_EXPORT int zsocket_multicast_hops (void *zocket);
CZMQ_EXPORT int zsocket_rcvtimeo (void *zocket);
CZMQ_EXPORT int zsocket_sndtimeo (void *zocket);
CZMQ_EXPORT int zsocket_ipv4only (void *zocket);
CZMQ_EXPORT int zsocket_rcvmore (void *zocket);
CZMQ_EXPORT int zsocket_fd (void *zocket);
CZMQ_EXPORT int zsocket_events (void *zocket);
//  Returns freshly allocated string, free when done
CZMQ_EXPORT char * zsocket_last_endpoint (void *zocket);

//  Set socket options
CZMQ_EXPORT void zsocket_set_sndhwm (void *zocket, int sndhwm);
CZMQ_EXPORT void zsocket_set_rcvhwm (void *zocket, int rcvhwm);
CZMQ_EXPORT void zsocket_set_affinity (void *zocket, int affinity);
CZMQ_EXPORT void zsocket_set_subscribe (void *zocket, char * subscribe);
CZMQ_EXPORT void zsocket_set_unsubscribe (void *zocket, char * unsubscribe);
CZMQ_EXPORT void zsocket_set_identity (void *zocket, char * identity);
CZMQ_EXPORT void zsocket_set_rate (void *zocket, int rate);
CZMQ_EXPORT void zsocket_set_recovery_ivl (void *zocket, int recovery_ivl);
CZMQ_EXPORT void zsocket_set_sndbuf (void *zocket, int sndbuf);
CZMQ_EXPORT void zsocket_set_rcvbuf (void *zocket, int rcvbuf);
CZMQ_EXPORT void zsocket_set_linger (void *zocket, int linger);
CZMQ_EXPORT void zsocket_set_reconnect_ivl (void *zocket, int reconnect_ivl);
CZMQ_EXPORT void zsocket_set_reconnect_ivl_max (void *zocket, int reconnect_ivl_max);
CZMQ_EXPORT void zsocket_set_backlog (void *zocket, int backlog);
CZMQ_EXPORT void zsocket_set_maxmsgsize (void *zocket, int maxmsgsize);
CZMQ_EXPORT void zsocket_set_multicast_hops (void *zocket, int multicast_hops);
CZMQ_EXPORT void zsocket_set_rcvtimeo (void *zocket, int rcvtimeo);
CZMQ_EXPORT void zsocket_set_sndtimeo (void *zocket, int sndtimeo);
CZMQ_EXPORT void zsocket_set_ipv4only (void *zocket, int ipv4only);
CZMQ_EXPORT void zsocket_set_delay_attach_on_connect (void *zocket, int delay_attach_on_connect);
CZMQ_EXPORT void zsocket_set_router_mandatory (void *zocket, int router_mandatory);
CZMQ_EXPORT void zsocket_set_xpub_verbose (void *zocket, int xpub_verbose);

//  Emulation of widely-used 2.x socket options
void zsocket_set_hwm (void *zocket, int hwm);
#endif

//  Self test of this class
int zsockopt_test (Bool verbose);

//  Receive a string off a socket, caller must free it
CZMQ_EXPORT char *
    zstr_recv (void *socket);

//  Receive a string off a socket if socket had input waiting
CZMQ_EXPORT char *
    zstr_recv_nowait (void *socket);

//  Send a string to a socket in ØMQ string format
CZMQ_EXPORT int
    zstr_send (void *socket, const char *string);

//  Send a string to a socket in ØMQ string format, with MORE flag
CZMQ_EXPORT int
    zstr_sendm (void *socket, const char *string);

//  Send a formatted string to a socket
CZMQ_EXPORT int
    zstr_sendf (void *socket, const char *format, ...);

//  Send formatted C string to socket with MORE flag
CZMQ_EXPORT int
    zstr_sendfm (void *socket, const char *format, ...);

//  Self test of this class
int
    zstr_test (Bool verbose);

//  Delete file. Does not complain if the file is absent
CZMQ_EXPORT int
    zfile_delete (const char *filename);

//  Make directory (maximum one level depending on OS)
CZMQ_EXPORT int
    zfile_mkdir (const char *dirname);

//  Return 1 if file exists, else zero
CZMQ_EXPORT int
    zfile_exists (const char *filename);

//  Return size of file, or -1 if not found
CZMQ_EXPORT ssize_t
    zfile_size (const char *filename);

//  Self test of this class
int
    zfile_test (Bool verbose);

#define ZFRAME_MORE     1
#define ZFRAME_REUSE    2
#define ZFRAME_DONTWAIT 4

//  Callback function for zframe_free_fn method
typedef void (zframe_free_fn) (void *data, void *arg);

//  Create a new frame with optional size, and optional data
CZMQ_EXPORT zframe_t *
    zframe_new (const void *data, size_t size);

//  Create a zero-copy frame
CZMQ_EXPORT zframe_t *
    zframe_new_zero_copy (void *data, size_t size,
                          zframe_free_fn *free_fn, void *arg);

//  Destroy a frame
CZMQ_EXPORT void
    zframe_destroy (zframe_t **self_p);

//  Receive frame from socket, returns zframe_t object or NULL if the recv
//  was interrupted. Does a blocking recv, if you want to not block then use
//  zframe_recv_nowait().
CZMQ_EXPORT zframe_t *
    zframe_recv (void *socket);

//  Receive a new frame off the socket. Returns newly allocated frame, or
//  NULL if there was no input waiting, or if the read was interrupted.
CZMQ_EXPORT zframe_t *
    zframe_recv_nowait (void *socket);

// Send a frame to a socket, destroy frame after sending.  Returns
// non-zero error code on failure.
CZMQ_EXPORT int
    zframe_send (zframe_t **self_p, void *socket, int flags);

//  Return number of bytes in frame data
CZMQ_EXPORT size_t
    zframe_size (zframe_t *self);

//  Return address of frame data
CZMQ_EXPORT byte *
    zframe_data (zframe_t *self);

//  Create a new frame that duplicates an existing frame
CZMQ_EXPORT zframe_t *
    zframe_dup (zframe_t *self);

//  Return frame data encoded as printable hex string
CZMQ_EXPORT char *
    zframe_strhex (zframe_t *self);

//  Return frame data copied into freshly allocated string
CZMQ_EXPORT char *
    zframe_strdup (zframe_t *self);

//  Return TRUE if frame body is equal to string, excluding terminator
CZMQ_EXPORT Bool
    zframe_streq (zframe_t *self, const char *string);

// Return frame zero copy indicator (1 or 0)
CZMQ_EXPORT int
    zframe_zero_copy (zframe_t *self);

//  Return frame 'more' property
CZMQ_EXPORT int
    zframe_more (const zframe_t *self);

//  Return TRUE if two frames have identical size and data
//  If either frame is NULL, equality is always false.
CZMQ_EXPORT Bool
    zframe_eq (zframe_t *self, zframe_t *other);

//  Print contents of frame to stderr
CZMQ_EXPORT void
    zframe_print (zframe_t *self, const char *prefix);

//  Set new contents for frame
CZMQ_EXPORT void
    zframe_reset (zframe_t *self, const void *data, size_t size);

//  Self test of this class
int
    zframe_test (Bool verbose);

//  Create a new empty message object
CZMQ_EXPORT zmsg_t *
    zmsg_new (void);

//  Destroy a message object and all frames it contains
CZMQ_EXPORT void
    zmsg_destroy (zmsg_t **self_p);

//  Read 1 or more frames off the socket, into a new message object
CZMQ_EXPORT zmsg_t *
    zmsg_recv (void *socket);

//  Send a message to the socket, and then destroy it
CZMQ_EXPORT int
    zmsg_send (zmsg_t **self_p, void *socket);

//  Return number of frames in message
CZMQ_EXPORT size_t
    zmsg_size (zmsg_t *self);

//  Return combined size of all frames in message
CZMQ_EXPORT size_t
    zmsg_content_size (zmsg_t *self);

//  Push frame to front of message, before first frame
CZMQ_EXPORT int
    zmsg_push (zmsg_t *self, zframe_t *frame);

//  Pop frame off front of message, caller now owns frame
CZMQ_EXPORT zframe_t *
    zmsg_pop (zmsg_t *self);

//  Add frame to end of message, after last frame
CZMQ_EXPORT int
    zmsg_add (zmsg_t *self, zframe_t *frame);

//  Push block of memory as new frame to front of message.
//  Returns 0 on success, -1 on error.
CZMQ_EXPORT int
    zmsg_pushmem (zmsg_t *self, const void *src, size_t size);

//  Push block of memory as new frame to end of message.
//  Returns 0 on success, -1 on error.
CZMQ_EXPORT int
    zmsg_addmem (zmsg_t *self, const void *src, size_t size);

//  Push string as new frame to front of message.
//  Returns 0 on success, -1 on error.
CZMQ_EXPORT int
    zmsg_pushstr (zmsg_t *self, const char *format, ...);

//  Push string as new frame to end of message.
//  Returns 0 on success, -1 on error.
CZMQ_EXPORT int
    zmsg_addstr (zmsg_t *self, const char *format, ...);

//  Pop frame off front of message, return as fresh string
CZMQ_EXPORT char *
    zmsg_popstr (zmsg_t *self);

//  Push frame to front of message, before first frame
//  Pushes an empty frame in front of frame
CZMQ_EXPORT void
    zmsg_wrap (zmsg_t *self, zframe_t *frame);

//  Pop frame off front of message, caller now owns frame
//  If next frame is empty, pops and destroys that empty frame.
CZMQ_EXPORT zframe_t *
    zmsg_unwrap (zmsg_t *self);

//  Remove frame from message, at any position, caller owns it
CZMQ_EXPORT void
    zmsg_remove (zmsg_t *self, zframe_t *frame);

//  Return first frame in message, or null
CZMQ_EXPORT zframe_t *
    zmsg_first (zmsg_t *self);

//  Return next frame in message, or null
CZMQ_EXPORT zframe_t *
    zmsg_next (zmsg_t *self);

//  Return last frame in message, or null
CZMQ_EXPORT zframe_t *
    zmsg_last (zmsg_t *self);

//  Save message to an open file, return 0 if OK, else -1.
CZMQ_EXPORT int
    zmsg_save (zmsg_t *self, FILE *file);

//  Load/append an open file into message, create new message if
//  null message provided.
CZMQ_EXPORT zmsg_t *
    zmsg_load (zmsg_t *self, FILE *file);

//  Encode message to a new buffer, return buffer size
CZMQ_EXPORT size_t
    zmsg_encode (zmsg_t *self, byte **buffer);

//  Decode a buffer into a new message, returns NULL if buffer is not
//  properly formatted.
CZMQ_EXPORT zmsg_t *
    zmsg_decode (byte *buffer, size_t buffer_size);

//  Create copy of message, as new message object
CZMQ_EXPORT zmsg_t *
    zmsg_dup (zmsg_t *self);

//  Print message to stderr, for debugging
CZMQ_EXPORT void
    zmsg_dump (zmsg_t *self);

//  Self test of this class
int
    zmsg_test (Bool verbose);

//  Callback function for reactor events
typedef int (zloop_fn) (zloop_t *loop, zmq_pollitem_t *item, void *arg);

//  Create a new zloop reactor
CZMQ_EXPORT zloop_t *
    zloop_new (void);

//  Destroy a reactor
CZMQ_EXPORT void
    zloop_destroy (zloop_t **self_p);

//  Register pollitem with the reactor. When the pollitem is ready, will call
//  the handler, passing the arg. Returns 0 if OK, -1 if there was an error.
//  If you register the pollitem more than once, each instance will invoke its
//  corresponding handler.
CZMQ_EXPORT int
    zloop_poller (zloop_t *self, zmq_pollitem_t *item, zloop_fn handler, void *arg);

//  Cancel a pollitem from the reactor, specified by socket or FD. If both
//  are specified, uses only socket. If multiple poll items exist for same
//  socket/FD, cancels ALL of them.
CZMQ_EXPORT void
    zloop_poller_end (zloop_t *self, zmq_pollitem_t *item);

//  Register a timer that expires after some delay and repeats some number of
//  times. At each expiry, will call the handler, passing the arg. To
//  run a timer forever, use 0 times. Returns 0 if OK, -1 if there was an
//  error.
CZMQ_EXPORT int
    zloop_timer (zloop_t *self, size_t delay, size_t times, zloop_fn handler, void *arg);

//  Cancel all timers for a specific argument (as provided in zloop_timer)
CZMQ_EXPORT int
    zloop_timer_end (zloop_t *self, void *arg);

//  Set verbose tracing of reactor on/off
CZMQ_EXPORT void
    zloop_set_verbose (zloop_t *self, Bool verbose);

//  Start the reactor. Takes control of the thread and returns when the ØMQ
//  context is terminated or the process is interrupted, or any event handler
//  returns -1. Event handlers may register new sockets and timers, and
//  cancel sockets. Returns 0 if interrupted, -1 if cancelled by a handler.
CZMQ_EXPORT int
    zloop_start (zloop_t *self);

//  Self test of this class
int
    zloop_test (Bool verbose);

//  Detached threads follow POSIX pthreads API
typedef void *(zthread_detached_fn) (void *args);

//  Attached threads get context and pipe from parent
typedef void (zthread_attached_fn) (void *args, zctx_t *ctx, void *pipe);

//  Create a detached thread. A detached thread operates autonomously
//  and is used to simulate a separate process. It gets no ctx, and no
//  pipe.
CZMQ_EXPORT int
    zthread_new (zthread_detached_fn *thread_fn, void *args);

//  Create an attached thread. An attached thread gets a ctx and a PAIR
//  pipe back to its parent. It must monitor its pipe, and exit if the
//  pipe becomes unreadable. Do not destroy the ctx, the thread does this
//  automatically when it ends.
CZMQ_EXPORT void *
    zthread_fork (zctx_t *ctx, zthread_attached_fn *thread_fn, void *args);

//  Self test of this class
int
    zthread_test (Bool verbose);

//  Callback function for zhash_foreach method
typedef int (zhash_foreach_fn) (const char *key, void *item, void *argument);
//  Callback function for zhash_freefn method
typedef void (zhash_free_fn) (void *data);

//  Create a new, empty hash container
CZMQ_EXPORT zhash_t *
    zhash_new (void);

//  Destroy a hash container and all items in it
CZMQ_EXPORT void
    zhash_destroy (zhash_t **self_p);

//  Insert item into hash table with specified key and item.
//  If key is already present returns -1 and leaves existing item unchanged
//  Returns 0 on success.
CZMQ_EXPORT int
    zhash_insert (zhash_t *self, const char *key, void *item);

//  Update item into hash table with specified key and item.
//  If key is already present, destroys old item and inserts new one.
//  Use free_fn method to ensure deallocator is properly called on item.
CZMQ_EXPORT void
    zhash_update (zhash_t *self, const char *key, void *item);

//  Remove an item specified by key from the hash table. If there was no such
//  item, this function does nothing.
CZMQ_EXPORT void
    zhash_delete (zhash_t *self, const char *key);

//  Return the item at the specified key, or null
CZMQ_EXPORT void *
    zhash_lookup (zhash_t *self, const char *key);

//  Reindexes an item from an old key to a new key. If there was no such
//  item, does nothing. Returns 0 if successful, else -1.
CZMQ_EXPORT int
    zhash_rename (zhash_t *self, const char *old_key, const char *new_key);

//  Set a free function for the specified hash table item. When the item is
//  destroyed, the free function, if any, is called on that item.
//  Use this when hash items are dynamically allocated, to ensure that
//  you don't have memory leaks. You can pass 'free' or NULL as a free_fn.
//  Returns the item, or NULL if there is no such item.
CZMQ_EXPORT void *
    zhash_freefn (zhash_t *self, const char *key, zhash_free_fn *free_fn);

//  Return the number of keys/items in the hash table
CZMQ_EXPORT size_t
    zhash_size (zhash_t *self);

//  Make copy of hash table
CZMQ_EXPORT zhash_t *
    zhash_dup (zhash_t *self);
    
//  Apply function to each item in the hash table. Items are iterated in no
//  defined order. Stops if callback function returns non-zero and returns
//  final return code from callback function (zero = success).
CZMQ_EXPORT int
    zhash_foreach (zhash_t *self, zhash_foreach_fn *callback, void *argument);

//  Self test of this class
void
    zhash_test (int verbose);

//  Comparison function for zlist_sort method
typedef bool (zlist_compare_fn) (void *item1, void *item2);

//  Create a new list container
CZMQ_EXPORT zlist_t *
    zlist_new (void);

//  Destroy a list container
CZMQ_EXPORT void
    zlist_destroy (zlist_t **self_p);

//  Return first item in the list, or null
CZMQ_EXPORT void *
    zlist_first (zlist_t *self);

//  Return last item in the list, or null
CZMQ_EXPORT void *
    zlist_last (zlist_t *self);

//  Return first item in the list, or null, leaves the cursor
CZMQ_EXPORT void *
    zlist_head (zlist_t *self);

//  Return last item in the list, or null, leaves the cursor
CZMQ_EXPORT void *
    zlist_tail (zlist_t *self);

//  Return next item in the list, or null
CZMQ_EXPORT void *
    zlist_next (zlist_t *self);

//  Append an item to the end of the list
CZMQ_EXPORT int
    zlist_append (zlist_t *self, void *item);

//  Push an item to the start of the list
CZMQ_EXPORT int
    zlist_push (zlist_t *self, void *item);

//  Pop the item off the start of the list, if any
CZMQ_EXPORT void *
    zlist_pop (zlist_t *self);

//  Remove the specified item from the list if present
CZMQ_EXPORT void
    zlist_remove (zlist_t *self, void *item);

//  Copy the entire list, return the copy
CZMQ_EXPORT zlist_t *
    zlist_dup (zlist_t *self);

//  Copy the entire list, return the copy (deprecated)
CZMQ_EXPORT zlist_t *
    zlist_copy (zlist_t *self);

//  Return number of items in the list
CZMQ_EXPORT size_t
    zlist_size (zlist_t *self);

//  Sort list
CZMQ_EXPORT void
    zlist_sort (zlist_t *self, zlist_compare_fn *compare);

//  Set list for automatic item destruction
CZMQ_EXPORT void
    zlist_autofree (zlist_t *self);

//  Self test of this class
void
    zlist_test (int verbose);

//  Sleep for a number of milliseconds
CZMQ_EXPORT void
    zclock_sleep (int msecs);

//  Return current system clock as milliseconds
CZMQ_EXPORT int64_t
    zclock_time (void);

//  Print formatted string to stdout, prefixed by date/time and
//  terminated with a newline.
CZMQ_EXPORT void
    zclock_log (const char *format, ...);

//  Self test of this class
int
    zclock_test (Bool verbose);

zclassname_methodname

zblob_t *file_buffer;       /*  Buffer for our file */
... (100 lines of code)
file_buffer = zblob_new ();
...

zblob_t *file_buffer = zblob_new ();

int rc = some_function (arguments);
assert (rc == 0);

assert (some_function (arguments) == 0);