In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: "You may use czmq.h which lets C developers to code their ZeroMQ applications easier and shorter."

A block of code is set as follows:

#include <string.h>
#include <stdio.h>
#include "zmq.h"


int main (int argc, char const *argv[]) {
  void* context = zmq_init(1);
  void* request = zmq_socket(context, ZMQ_REQ);
  printf("Connecting to server
");
  zmq_connect(request, "tcp://localhost:4040");
  
  zmq_close(request);
  zmq_term(context);
  return 0;
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

#include <string.h>
#include <stdio.h>
#include "zmq.h"

int main (int argc, char const *argv[]) {
  void* context = zmq_init(1);
  void* request = zmq_socket(context, ZMQ_REQ);
  printf("Connecting to server
");
  zmq_connect(request, "tcp://localhost:4040");
  
  zmq_close(request);
  zmq_term(context);
  return 0;
}

Any command-line input or output is written as follows:

gcc -Wall -lzmq -o zero zero.c

When we say zmq_socket(2) we mean zmq_socket function takes two parameters. When we say zmq_ctx_new() we mean zmq_ctx_new function does not take any parameters.

New terms and important words are shown in bold.