Preface

This book provides programming and reference information for developers working with Message Queue 4.5.2, who want to use the C language binding to the Message Queue Service to send, receive, and process Message Queue messages.

This preface consists of the following sections:

Who Should Use This Book
Before You Read This Book
How This Book Is Organized
Documentation Conventions
Related Documentation
Documentation, Support, and Training
Documentation Accessibility

Who Should Use This Book

This guide is for developers who want to use the C-API in order to write C or C++ messaging programs that can interact with the Message Queue broker to send and receive JMS messages.

This book assumes that readers are experienced C or C++ programmers and that they are familiar with the Java Message Service specification.

Before You Read This Book

You must read the Oracle GlassFish Server Message Queue Technical Overview to become familiar with Message Queue's implementation of the Java Message Service specification, with the components of the Message Queue service, and with the basic process of developing, deploying, and administering a Message Queue application.

How This Book Is Organized

This guide is designed to be read from beginning to end. The following table briefly describes the contents of each chapter.

Chapter	Description
Chapter 1, "Introduction"	Introduces the C-API, provides quick start instructions on compiling and building Message Queue C clients. Introduces the Message Queue C-Client sample applications that are shipped with Message Queue, and explains how you set up your environment to run these examples. Provides a deployment worksheet.
Chapter 2, "Using the C API"	Explains how you use the C-API to construct, to send, to receive, and to process messages. This chapter also covers error handling, memory management, and logging.
Chapter 3, "Client Design Issues"	Explains the major considerations that you need to keep in mind when designing a Message Queue C client.
Chapter 4, "Reference"	Provides complete reference information for the Message Queue C-API: data structures and functions. It also lists and describes the contents of the C-API header files.
Appendix A, "Message Queue C API Error Codes"	Lists the code and descriptive string returned for errors that are returned by C library functions.

Documentation Conventions

This section describes the following conventions used in Message Queue documentation:

Typographic Conventions
Symbol Conventions
Shell Prompt Conventions
Directory Variable Conventions

Typographic Conventions

The following table describes the typographic conventions that are used in this book.

Typeface	Meaning	Example
`AaBbCc123`	The names of commands, files, and directories, and onscreen computer output	Edit your `.login` file. Use `ls` `a` to list all files. `machine_name% you have mail.`
`AaBbCc123`	What you type, contrasted with onscreen computer output	`machine_name%` `su` `Password:`
aabbcc123	Placeholder: replace with a real name or value	The command to remove a file is `rm` filename.
AaBbCc123	Book titles, new terms, and terms to be emphasized	Read Chapter 6 in the User's Guide. A cache is a copy that is stored locally. Do not save the file. Note: Some emphasized items appear bold online.

Symbol Conventions

The following table explains symbols that might be used in this book.

Symbol	Description	Example	Meaning
`[ ]`	Contains optional arguments and command options.	`ls [-l]`	The `-l` option is not required.
`{ \| }`	Contains a set of choices for a required command option.	`-d {y\|n}`	The `-d` option requires that you use either the `y` argument or the `n` argument.
`${ }`	Indicates a variable reference.	`${com.sun.javaRoot}`	References the value of the `com.sun.javaRoot` variable.
-	Joins simultaneous multiple keystrokes.	Control-A	Press the Control key while you press the A key.
+	Joins consecutive multiple keystrokes.	Ctrl+A+N	Press the Control key, release it, and then press the subsequent keys.
>	Indicates menu item selection in a graphical user interface.	File > New > Templates	From the File menu, choose New. From the New submenu, choose Templates.

Shell Prompt Conventions

The following table shows the conventions used in Message Queue documentation for the default UNIX system prompt and superuser prompt for the C shell, Bourne shell, Korn shell, and for the Windows operating system.

Shell	Prompt
C shell on UNIX, Linux, or AIX	machine-name`%`
C shell superuser on UNIX, Linux, or AIX	machine-name`#`
Bourne shell and Korn shell on UNIX, Linux, or AIX	`$`
Bourne shell and Korn shell superuser on UNIX, Linux, or AIX	`#`
Windows command line	`C:\>`

Directory Variable Conventions

Message Queue documentation makes use of three directory variables; two of which represent environment variables needed by Message Queue. (How you set the environment variables varies from platform to platform.)

The following table describes the directory variables that might be found in this book and how they are used. Some of these variables refer to the directory mqInstallHome, which is the directory where Message Queue is installed to when using the installer or unzipped to when using a zip-based distribution.

Note:

In this book, directory variables are shown without platform-specific environment variable notation or syntax (such as $IMQ_HOME on UNIX). Non-platform-specific path names use UNIX directory separator (/) notation.

Variable Description

Variable	Description
`IMQ_HOME`	The Message Queue home directory: For installations of Message Queue bundled with GlassFish Server, `IMQ_HOME` is as-install-parent`/mq`, where as-install-parent is the parent directory of the GlassFish Server base installation directory, `glassfish3` by default. For installations of Open Message Queue, `IMQ_HOME` is mqInstallHome`/mq`.
`IMQ_VARHOME`	The directory in which Message Queue temporary or dynamically created configuration and data files are stored; `IMQ_VARHOME` can be explicitly set as an environment variable to point to any directory or will default as described below: For installations of Message Queue bundled with GlassFish Server, `IMQ_VARHOME` defaults to as-install-parent`/glassfish/domains/domain1/imq`. For installations of Open Message Queue, `IMQ_HOME` defaults to mqInstallHome`/var/mq`.
`IMQ_JAVAHOME`	An environment variable that points to the location of the Java runtime environment (JRE) required by Message Queue executable files. By default, Message Queue looks for and uses the latest JDK, but you can optionally set the value of `IMQ_JAVAHOME` to wherever the preferred JRE resides.

IMQ_HOME

The Message Queue home directory:

For installations of Message Queue bundled with GlassFish Server, IMQ_HOME is as-install-parent/mq, where as-install-parent is the parent directory of the GlassFish Server base installation directory, glassfish3 by default.
For installations of Open Message Queue, IMQ_HOME is mqInstallHome/mq.

IMQ_VARHOME

The directory in which Message Queue temporary or dynamically created configuration and data files are stored; IMQ_VARHOME can be explicitly set as an environment variable to point to any directory or will default as described below:

For installations of Message Queue bundled with GlassFish Server, IMQ_VARHOME defaults to as-install-parent/glassfish/domains/domain1/imq.
For installations of Open Message Queue, IMQ_HOME defaults to mqInstallHome/var/mq.

IMQ_JAVAHOME

An environment variable that points to the location of the Java runtime environment (JRE) required by Message Queue executable files. By default, Message Queue looks for and uses the latest JDK, but you can optionally set the value of IMQ_JAVAHOME to wherever the preferred JRE resides.

Related Documentation

The information resources listed in this section provide further information about Message Queue in addition to that contained in this manual. The section covers the following resources:

Message Queue Documentation Set
Java Message Service (JMS) Specification
JavaDoc
Example Client Applications
Online Help

Message Queue Documentation Set

The documents that constitute the Message Queue documentation set are listed in the following table in the order in which you might normally use them. These documents are available through the Oracle GlassFish Server documentation web site at

http://www.oracle.com/technetwork/indexes/documentation/index.html

Document	Audience	Description
Technical Overview	Developers and administrators	Describes Message Queue concepts, features, and components.
Release Notes	Developers and administrators	Includes descriptions of new features, limitations, and known bugs, as well as technical notes.
Administration Guide	Administrators, also recommended for developers	Provides background and information needed to perform administration tasks using Message Queue administration tools.
Developer's Guide for Java Clients	Developers	Provides a quick-start tutorial and programming information for developers of Java client programs using the Message Queue implementation of the JMS or SOAP/JAXM APIs.
Developer's Guide for C Clients	Developers	Provides programming and reference documentation for developers of C client programs using the Message Queue C implementation of the JMS API (C-API).
Developer's Guide for JMX Clients	Administrators	Provides programming and reference documentation for developers of JMX client programs using the Message Queue JMX API.

Java Message Service (JMS) Specification

The Message Queue message service conforms to the Java Message Service (JMS) application programming interface, described in the Java Message Service Specification. This document can be found at the URL http://www.oracle.com/technetwork/java/jms/index.html.

JavaDoc

JMS and Message Queue API documentation in JavaDoc format is included in Message Queue installations at IMQ_HOME/javadoc/index.html. This documentation can be viewed in any HTML browser. It includes standard JMS API documentation as well as Message Queue–specific APIs.

Example Client Applications

Message Queue provides a number of example client applications to assist developers.

Example Java Client Applications

Example Java client applications are included in Message Queue installations at IMQ_HOME/examples. See the README files located in this directory and its subdirectories for descriptive information about the example applications.

Example C Client Programs

Example C client applications are included in Message Queue installations at IMQ_HOME/examples/C. See the README files located in this directory and its subdirectories for descriptive information about the example applications.

Example JMX Client Programs

Example Java Management Extensions (JMX) client applications are included in Message Queue installations at IMQ_HOME/examples/jmx. See the README files located in this directory and its subdirectories for descriptive information about the example applications.

Online Help

Online help is available for the Message Queue command line utilities; for details, see "Command Line Reference" in Oracle GlassFish Server Message Queue Administration Guide. The Message Queue graphical user interface (GUI) administration tool, the Administration Console, also includes a context-sensitive help facility; for details, see "Administration Console Online Help" in Oracle GlassFish Server Message Queue Administration Guide.

Documentation, Support, and Training

The Oracle web site provides information about the following additional resources:

Documentation Accessibility

For information about Oracle's commitment to accessibility, visit the Oracle Accessibility Program website at http://www.oracle.com/pls/topic/lookup?ctx=acc&id=docacc.

Access to Oracle Support

Oracle customers have access to electronic support through My Oracle Support. For information, visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=info or visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs if you are hearing impaired.