Tag: C++

Debugging a CodeBlocks Application with Command Line Arguments

This is an update of a post that originally appeared on November 1, 2011.

Most application environments provide a means of setting command line arguments and CodeBlocks is no exception. The example shown in Listing 6-12 on page 167 of C++ All-In-One for Dummies, 4th Edition requires that you set command line arguments in order to see anything but the barest output from the debugger. This post discusses the requirements for setting command line arguments for debugging purposes.

Let’s begin with the example without any configuration. Every application has one command line argument—the path and application executable name. To see this argument, change the line that currently reads for (int index=1; index < argc; index++) to read for (int index=0; index < argc; index++) instead (setting index=1 causes the program not to show the first argument). So, now when you run the example shown in Listing 6-12 you’ll see the path and executable name as a minimum, as shown here.

The first argument passed to an application is the application executable name and path.
The first argument passed to an application.

If you run this example, you may see a different path, but the command line executable should be the same. The point is that you see at least one argument as output. However, most people will want to test their applications using more than one argument. In order to do this, you must pass command line arguments to the application. Start by changing the code back to its original form where index=1. The following steps tell how to perform add command line arguments.

  1. Choose Project | Set Program’s Arguments. You’ll see the Select Target dialog box shown here.
    Change the command line arguments for the debug or release versions.
  2. Select Debug as the target, as shown in the figure.
  3. Type the arguments you want to use, such as Hello World I Love You!, in the Program Arguments field and click OK. The IDE is now set to provide command line arguments to the application when you’re using the specified target, which is Debug in this case.

When you run the application after adding the command line argument, you should see them in the output like this:

The output shows addition of the command line arguments.
The output shows addition of the command line arguments.

Testing for command line arguments in a CodeBlocks application consists of telling the IDE what to pass in the Select Target dialog box. Let me know if you have any questions about this process at [email protected].

Resetting Your Code::Blocks Configuration

This is an update of a post that originally appeared on April 12, 2013.

Quite a few people have written to me about issues they have with C++ All-In-One for Dummies, 4th Edition that involve getting Code::Blocks up and running. The posts in the C++ All-in-One for Dummies, 4th Edition archive normally provide everything needed to get the compiler up and running. However, there are rare times when no matter how much you try, you simply can’t get the compiler to work.

One technique I haven’t really covered until now is to reset the Code::Blocks configuration. The problem with this approach is that it resets all of your settings, not just those that could be in error. This is the reason that I’ve taken a more measured approach to helping readers through problems until now. My concern is that resetting everything will actually cause more problems and end up confusing some readers, so you really do want to try those other posts first. That said, there are situations where resetting Code::Blocks is the only course of action that will work.

To reset your settings, open your copy of CodeBlocks. Choose Settings | Compiler. You see the Compiler and Debugger Settings dialog box similar to the one shown here.

A view of the Global Compiler Settings dialog box.
A view of the Global Compiler Settings dialog box.

Click Reset Defaults. This action will reset all of the defaults so that they match the initial installation configuration unless you have created a default of your own. Make absolutely certain that the Selected Compiler field shows GNU GCC Compiler as shown in the figure and then click OK. Close and then reopen Code::Blocks before you test your configuration.

Let me know if you have any questions about this procedure at [email protected]. It’s always my goal to make my books as useful to you as possible.

Choosing a C++ Editor

This is an update of a post that originally appeared on August 25, 2014.

A lot of people have asked why I chose Code::Blocks as the editor for C++ All-In-One for Dummies, 4th Edition. There are a number of reason that I chose this particular editor including:

  • Ease of use
  • Free download
  • Runs on a large number of platform types
  • Provides internationalization support

However, the fact that Code::Blocks works well for the book and for most beginning projects doesn’t mean it’s the best solution for your particular needs. There are many different C++ Integrated Development Environments (IDEs) out there and I’m constantly trying new products. When the new version of Visual Studio comes out, you can be sure I’ll obtain a copy and check it out because some of my readers use Visual Studio. The problem with Visual Studio is that it tends to use Microsoft additions to the C++ language and it also doesn’t run on all the platforms that the book must support. However, if you’re working with Microsoft systems and need to create a relatively large project, Visual Studio might be a good choice for you—only you can make that determination.

The Eclipse IDE is another good selection. I had thought about using Eclipse for C++ All-in-One for Dummies, 4th Edition, but after reviewing the IDE and comparing it to Code::Blocks, I felt Code::Blocks was a lot simpler. Even so, if you need great multiplatform support for your C++ projects, Eclipse is a great choice.

I recently looked at another IDE, Intel® oneAPI Base Toolkit. This is most definitely not a IDE for the faint of heart or the light of pocketbook (the asking price for the cheap version is $1,499.00). The main reason to obtain a product like this one is that it provides phenomenal parallelism support for multiprocessor applications. In other words, you use this sort of IDE for high end projects. You can read all the other features this product offers on the vendor site. One of the other items that grabbed my attention is that it provides both multiplatform (Windows, Mac, Linux, and Android) and multiformat (Phone, Tablet, PC, Ultrabook, and Server) support. Whether this particular IDE makes sense for your needs depends on the kind of applications you create.

Although the information in Wikipedia is often suspect, you can find a comparison of various IDEs at http://en.wikipedia.org/wiki/Comparison_of_integrated_development_environments. The best way to choose a C++ IDE is to look for a product that meets your needs and then try it out on a subset of the problem you’re trying to solve. Researching the IDE you use is essential because a mistake can cost you a lot of time later. Not every IDE support every C++ feature, every platform, or every team need. Tell me why you think I should move to something other than Code::Blocks for the next edition of the book at [email protected].

Pausing the C++ Example Output

This is an update of a post that originally appeared on December 23, 2013.

A number of readers have written to ask about running the example code in C++ All-In-One for Dummies, 4th Edition. The book shows that the examples pause so you can see the output, yet a few people experience problems getting the example to pause as shown in the book. Let’s take the first book example. When you run the example, you should see a command window similar to the one shown here open.

The paused output of a Code::Blocks example.
The paused output of a Code::Blocks example.

This is how the command window looks in Windows, but if you use some other operating system, you should see something similar. Notice that the output is paused. Pressing any key will cause the window to disappear and the example to end. The purpose of pausing the output is so that you can see the result.

There are two common reasons that people aren’t seeing the output pause. The most common reason is that the example is run in debug mode. Make sure you click Run or choose Build | Run to execute the example. If you click Debug/Continue or choose Debug | Start/Continue instead, the example will execute without pausing and you won’t see the output. Of course, you can always set a breakpoint to get the example to pause, but most people simply want to see the example output which means running the example, rather than debugging the example.

A less common cause is that the project environment is configured incorrectly. Normally the Code::Blocks environment automatically pauses when you run the example. However, it’s possible to set Code::Blocks not to pause. Some readers inadvertently change this setting while exploring the environment. In order to check this setting, choose Project | Properties to display the Project Targets/Options dialog box. Select the Build Targets tab and you see the dialog box shown here.

The Build Targets tab of the Project Properties dialog box contains a Pause When Execution Ends setting.
Changing the default Code::Blocks settings can cause the IDE not to pause the output.

Notice the Pause When Execution Ends option. If this option is cleared, the example won’t pause when you run it. Make sure this option is checked and click OK. The projects that come with the downloadable code all have this setting set up correctly.

Of course, there could always be other reasons why the examples aren’t pausing. Please let me know if you have any problems setting the example output. It’s essential that you be able to see the example output as you follow along in the book to understand how C++ works. Send your queries about this (or any other book-specific) topic to [email protected]. I always want to ensure you have the best possible experience when using my books.

Finding Code::Blocks Tutorials

This is an update of a post that originally appeared on February 10, 2014.

Sometimes it’s hard to know precisely how to cover information in a book because each reader’s needs are different. One reader may be somewhat knowledgeable and not need tutorials, another reader might me a complete novice and require more assistance. Over the years, I’ve come to appreciate the landslide of comments I receive about my language books when they deviate to discuss topics other than the language. Most readers don’t want to read about anything other than the language. In fact, in a few of my language books I’ve stopped mentioning any sort of IDE except in passing (and sometimes not at all).

C++ All-In-One for Dummies, 4th Edition is a little different from most of my language books in that it must make mention of an IDE in order for the reader to follow all of the examples. (In fact, there are two: one for mobile development and another for desktop development, this post is specific to Code::Blocks, which is used at the desktop.) Because I want the book to work well on all platforms, I’ve chosen Code::Blocks as the IDE for this book. This particular IDE works on all of the platforms that the book supports (Mac, Linux, and Windows) in a similar fashion, so one set of instructions works for everyone. In addition, Code::Blocks enjoys great community support and has a large enough user base that it’ll be around for a long time.

This book does contain a few bits of information about Code::Blocks because it must in order for the reader to follow the examples. However, I’ve purposely kept the amount of information about Code::Blocks to a minimum because this really is a language book and you could use any IDE with it, not just Code::Blocks. It’s difficult to walk the line between providing enough information about the IDE and not enough. Whether I’m successful depends on the skill level of the reader for the most part. The beta readers of the current edition are definitely letting me know where I need to add more information to ensure the material is understandable, but there will always be some room for readers to feel there is either too much or too little coverage.

With this in mind, I’ve provided tutorial-type posts in the C++ All-in-One for Dummies category. If you have a question about how to perform a task in the book, this is the first place to look. Make sure you contact me at [email protected] if you have questions, because then I’ll know to discuss the topic as part of a blog post. What it all comes down to is my wanting to provide you with the information you need, but not knowing what that requirement is until you contact me.

Code::Blocks also comes with a nice help file, but you might not know it. Choose the Help | Codeblocks option and you’ll see a new window pop up with the help information. I must admit that it would have been better had the vendor provided a different command for accessing the help file, but at least the help file is there.

Even with these two resources, you’ll likely find situations where you need more information. As I said, Code::Blocks enjoys good support in the development community. The following list contains some tutorials you can try when none of the other sources I’ve mentioned help.

There are other tutorials available. What I need to know is whether these tutorials answer your questions or not. If not, what topics do you need covered that my blog doesn’t already discuss? It’s important to me that you have a good learning experience with my books so always feel free to contact me about topics you’d like to see covered in the blog.

Mind Boggling Questions in C++

This is an update of a post that originally appeared on December 13, 2011.

I constantly tell readers they need to view my books as a starting point, rather than the end of their education on a particular subject. This sentiment holds true for C++ All-In-One for Dummies, 4th Edition as it does for all of my books. When you read this book, you get a really good start with C++. By the time you’re finished, you can create some useful applications and you know enough about the Code::Blocks IDE to use it effectively. Fortunately, there are many places online to expand when it comes to C++ and I ran across one of them in an article entitled, Amusing C++. The title, more than anything else, caught my attention. What, after all, could be amusing about C++?

This is one of those sorts of articles I wish I had thought to write myself. The author has a unique perspective about C++ and some of the issues you could face when working with it. More importantly, the article uncovers some interesting compatibility issues between compilers, all the while having fun with the C++ language.

These sorts of mind boggling questions force even professional developers to think about the language and how it works. It may seem as if a language specification is solid, but then you see that there are gaps in how the specification is put together and that there is room in the standards for unique vendor implementations. Working with unique implementations can lead to innovation, but it can also lead to all sorts of compatibility issues when you need to move your application from one product to another.

After you’ve completed reading my book, make sure you continue on with online resources. Of course, the place that you should look first for issues related to this book (and some general interest C++ topics) is the C++ All-in-One for Dummies, 4th Edition category on this blog. It’s a shame that this particular Dummies book doesn’t include the Parts of Tens feature that is found in other Dummies books. However, here are ten places you can look for C++ materials and examples:

Where do you get additional information about C++? What sorts of information do you look for on these sites? Let me know at [email protected].

Comment and Document Updates for CI/CD

In reading about Continuous Integration/Continuous Deployment (CI/CD) I often find ways to manage the code, to get people around the code, to keep errors out of the code, and so on. It’s all about the code. Developers have, in fact, developed myriad ways to keep code size small, updated, deployed, tested, and so on to ensure that users have what they want, when the they want it (if not before). Sometimes my head spins on its axis after reading such documents because it becomes a high speed dizzying affair. It’s somehow assumed that everyone can just keep up. Except, there are new people and older people and people with lesser attention spans who can’t keep up, which is why comments and documentation are so important.

As part of the coding process, developers also need to update both comments and documentation or someone will come along and make modifications based on outdated information. Even though making such updates seems like a waste of time since everyone should be able to keep up, the truth is that these updates ultimately save time. However, the updates, when they occur (which apparently isn’t often) are often made in a haphazard manner reminiscent of an old Keystone Cops movie.

Adding a process, a workflow, to the CI/CD mill is important to ensure that everything remains in sync: code, comments, and documentation. A best practice way to accomplish this task is to add steps to every update process so that nothing is left behind. Here’s how you could approach the problem:

  1. Perform the required code updates.
  2. During testing, ensure that the comments within the code actually match what the code is doing. Testing and other review processes should not only look at the code, but the comments too.
  3. Update the documentation as final testing occurs. Make sure to include these elements:
    • Text
    • Drawings
    • Mockups
    • Visual Aids
    • Videos
    • Any other documentation elements
  4. Specify that any old comments/documentation are outdated using one of these approaches:
    • Mark it as deprecated
    • Remove it from the work area and put it in an archive
    • Delete it completely
  5. Deploy the application update. If you don’t deploy the update after these steps are done, they won’t get done. Everyone will wander off somewhere and forget all about any sort of comment or documentation update.

Obviously, the approach you end up using has to meet the requirements of your organization. It also has to be simple enough that people will actually, albeit begrudgingly, perform the work. What methods do you use to keep everything in sync at your organization? Let me know at [email protected].

Choosing the GNU C++ Compiler

This is an update of a post that originally appeared on April 23, 2012.

A number of readers have written to ask me about the reason I chose the GNU C++ computer for C++ All-In-One for Dummies, 4th Edition. After all, there are many different C++ compilers on the market today. Here are the reasons I feel that the GNU C++ Compiler is the best choice today:

  • Standards Adherence: From what I’ve read and seen in my own coding efforts, the GNU C++ compiler adheres a bit better to the current standards. There are other compilers, such as Microsoft’s Visual C++, that include a host of special additions and exceptions that don’t adhere to the standard. Given the audience for this book, using a compiler that’s strong on the standards is a must. (This book doesn’t use any of the GNU C++ extensions.)
  • Cross-Platform Compatibility: This book has a mixed audience. I’ve received so many e-mails from Macintosh readers that I’ve provided a number of blog posts just for this group. Linux developers also like this compiler and have used my book to learn how to use it. Because there are so many different platforms that this compiler works on, I can reach a much broader audience with the book and help more people write applications in C++ as a result.
  • CodeBlocks Support: In order to write good C++ code, you really do need a good IDE. CodeBlocks is a free compiler that works well on Linux, Macintosh, and Windows machines. If I had chosen another compiler, it may not have been possible to provide great support for all three platforms and some readers would have been left out.
  • Community Support: Both the GNU C++ compiler and CodeBlocks enjoy a broad range of support from the open source community. Getting help with either product is relatively easy and normally free.
  • Cost: Many of the readers of this book are students of limited means or are hobbyists learning to write C++ applications on a shoestring. Using the GNU C++ compiler coupled with CodeBlocks offers a method of teaching C++ programming that doesn’t require any investment by the reader. If cost hadn’t been a factor, there are probably other compilers on the market that might be a little better choice than using GNU C++.
  • Mobile Device Support: Many of my readers now what to be able to code from anywhere at anytime using their mobile device. Quite a few of the online compilers rely on GNU C++. (You also find support for Android devices in the book now using CppDroid in Chapter 2.) In many respect, you could view this as a fourth supported platform for my book.

Yes, I could have used some other compiler when writing this book, but at the time, GNU C++ seemed to be the best choice available and I still think it’s the best choice today. Of course, it’s always nice to hear about alternatives. If you think there is a strong competitor for GNU C++ that’s free and runs on all three of the target platforms for this book, let me know at [email protected]. Make sure you provide me with complete information, including a URL for the compiler’s site.

Creating a CodeBlocks Project with Multiple Existing Files

This is an update of a post that originally appeared on July 26, 2011.

Most real world C++ projects include multiple source files. Book I Chapter 7 of C++ All-In-One for Dummies, 4th Edition shows how to create a project that has multiple source files starting on page 170. The first example (page 177), found in \CPP_AIO4\BookI\Chapter07\MultipleSourceFiles, discusses two .cpp files. The second example starts on page 179 and you find it in \CPP_AIO4\BookI\Chapter07\MultipleSourceFiles2. This example includes two .cpp files and a single .h file. I’ll use the files from the second example for this post. The example works the same as the one in the book, but in this case, we’ll start with the three files and create a project around them.

Defining the Project

You need to start with a Code::Blocks project. It’s possible to use either an existing project or create a new project to hold the files (I’m doing the latter and naming the new product MultipleSourceFiles3). In either case, once you have a project to use, you simply add the files you want to it, set the build options for those files, and then create your application. The following steps create a new project, add the files from MultipleSourceFiles2 to it, set the build options, compile the resulting project, and show you the results.

  1. Choose File > New > Project. You’ll see the New From Template dialog box.
  2. Highlight the Empty Project template as shown here:
  3. Click Go. You’ll see the Empty Project wizard. If you’re seeing the Welcome screen, click Next to get past it.
  4. Type the name of the project (the example uses MultipleSourceFiles3) in the Project Title field and choose a location for the project (the example uses \CPP_AIO4\BookI\Chapter07\) in the Location field. If you’re following the example, your wizard should look similar to the one shown here:The Empty Project configuration information for MultipleSourceFiles3.
  5. Click Next. Look in the Compiler field and ensure that the GNU GCC Compiler option is selected.
  6. Click Finish. The wizard creates a blank project for you.

Referencing the Other Project Source Files

At this point, you have an empty project without any files in it. However, you can add files to any existing project. The following steps add the files from the MultipleSourceFiles2 project to this project.

  1. Right click the project entry (MultipleSourceFiles3) in the Projects tab of the Management window and choose Add Files from the context menu. You see the Add Files to Project dialog box shown here: Adding new files to an empty project.
  2. Locate the \CPP_AIO4\BookI\Chapter07\MultipleSourceFiles2 folder on your system.
  3. Click on main.cpp. Ctrl+Click on safestuff.cpp and safestuff.h. You’ll see all three files added to the File Name field.
  4. Click Open. You’ll see the Multiple Selection dialog box. This dialog box contains entries for each of the builds that you specified when creating the project. The default is to use the files you’re adding in all of the builds as shown here. (The example uses all of the files in all of the builds.)Ensure the that targets will appear in all build types.
  5. Configure the files you’ve selected by choosing the build the file should appear part of and click OK. You’ll see all three files added below the MultipleSourceFiles3 entry in the Projects tab of the Management window as shown here:The files from MultipleSourceFiles2 are referenced in this project.

The referencing technique adds existing files to a different project. Notice that the files are still referenced in the original project. If you make a change to these files, the changes will also appear in the original project.

Copying the Other Project Source Files

Referencing files isn’t always what you want to do. So, you need an alternative for those situations where you want a copy of the file in a new project (allowing changes in the new project that won’t affect the existing project). In this case, follow these steps instead:

  1. Right click the project entry (MultipleSourceFiles3) in the Projects tab of the Management window and choose Add Files from the context menu. You see the Add Files to Project dialog box.
  2. Locate the \CPP_AIO4\BookI\Chapter07\MultipleSourceFiles2 folder on your system.
  3. Click on main.cpp. Ctrl+Click on safestuff.cpp and safestuff.h. You’ll see all three files added to the File Name field.
  4. Right click main.cpp and choose Copy from the context menu.
  5. Locate the \CPP_AIO4\BookI\Chapter07\MultipleSourceFiles3 folder on your system.
  6. Right click inside the file selection area and choose Paste from the context menu. You see the files pasted into the new location as shown here: Actually copying the files to a new location.
  7. Click Open. You’ll see the Multiple Selection dialog box.
  8. Configure the files you’ve selected by choosing the build the file should appear part of and click OK. You’ll see all three files added below the MultipleSourceFiles3 entry in the Projects tab of the Management window as shown here (notice that they’re now actually part of MultipleSourceFiles3 and not just a reference):The files are now copied, not referenced.

Many developers find the need to use existing files in a project. It’s something you’ll do quite often, especially with header files. Of course, when working with header files you also have the option of using the #include directive. Please let me know if you have any questions about this process at [email protected].

Choosing a First Language to Learn

My first programming experience (during the time of the dinosaurs) involved using a light panel to enter machine code into a rudimentary computer with 3 KB (yes, that’s KB) of RAM. The output was also in light form and I needed to decode the lights to determine if my code worked right. I worked with various systems in various ways over the next several years. By the time I got to college, the first language I learned there was BASIC (Beginner’s All-purpose Symbolic Instruction Code), then PC assembler, followed by Pascal. In fact, I’ve just stopped counting the number of languages I’ve learned over the years because each language has a place in my programmer’s toolbox. Of course, the question is what language you should learn first. I get asked that question quite often because there are a huge number of languages available today and no one wants to invest time in a language that’s going nowhere.

Part of the answer to the question of what to learn first is what you intend to do with the language. Each language has features that make it better at performing specific tasks. Programming languages can be split into those that are designed for a special purpose and those that are designed for a general purpose. A special purpose language, such as Structured Query Language (SQL), could be a good choice if you intend to move into database work immediately. However, for most people, a general purpose language works better because you can use it for a wider variety of tasks without bending yourself into a pretzel shape to do it.

A good place to start if you want to choose a language that’s popular enough to help you get a job afterward is the TIOBE index. It shows a listing of which languages are most popular today. As I’m writing this, Python is the most popular language on the list, but that could change tomorrow. Generally, any of the top ten languages on the list are good choices.

Of course, you want a programming language that is easy to learn. C/C++, C#, and Java are all complex languages with great flexibility. Furthermore, C/C++ and C# can help you work at a low level with the computer hardware. These languages have a steep learning curve and may not provide the best choices for a starting point. That said, if you have a line on a job that uses any of these languages, you could do worse than start here, just be prepared to burn the midnight oil learning.

The language I suggest people learn as a starting point is Python. In fact, Beginning Programming with Python For Dummies, 3rd Edition makes a point of showing you just how easy things can be. You don’t even need to invest in any special software, the book shows you how to use Google Colab so that you could conceivably learn how to program on your smartphone or TV. Others must agree with me because Python has turned into the language that the education industry turns to most often for budding programmers.

There are a lot of programming languages available today. You need to research the choice by taking into account what your personal needs are and what sort of job you want to get afterwards. You might find that something like JavaScript or Ruby will provide benefits that you can’t get with Python. Which language do you think will work best for you? Let me know your reasons at [email protected].