Tag: Windows

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.

Using the Set Command to Your Advantage

This is an update of a post that originally appeared on February 24, 2014.

A short while ago, I created a post about the Windows path. A number of people wrote me about that post with questions. Yes, you can use the technique for setting the Path environment variable to set any other environment variable. The Windows Environment Variables dialog box works for any environment variable—including those used by language environments such as Java, JavaScript, and Python. Windows doesn’t actually care what sort of environment variable you create using the method that I discuss in that post. The environment variable will appear in every new command prompt window you create for either a single user or all users of a particular system, depending on how you create the environment variable.

A few of you took me to task for not mentioning the Set command. This particular command appears in Microsoft Windows Command Line Administration Instant Reference. It’s a useful command because you can temporarily configure a command prompt session to support a new set of settings. When the session is ended, the settings are gone. Only those settings you create as part of Environment Variables window have any permanence. There are other tricks you can use, but using Set for temporary environment variables and the Environment Variables window for permanent environment variables are the two most common approaches.

In order to see the current environment variables you simply type Set and press Enter at the command line. If you add a space and one or more letters, you see just the matching environment variables. For example, type Set U and press Enter to see all of the environment variables that begin with the letter U.

To set an environment variable, you add the name of the variable, an equals sign (=), and the variable value. For example, to set the value of MyVariable to Hello, you type Set MyVariable=Hello and press Enter. To verify that MyVariable does indeed equal Hello, you type Set MyVariable and press Enter. The command prompt will display the value of MyVariable. When you’re done using MyVariable, you can type Set MyVariable= and press Enter. Notice the addition of the equals sign. If you ask for the value of MyVariable again, the command prompt will tell you it doesn’t exist.

Newer versions of the command prompt provide some additional functionality. For example, you might set MyVariable within a batch file and not know what value it should contain when you create the batch file. In this case, you can prompt the user to provide a value using the /P command line switch. For example, if you type Set /P MyVariable=Type a value for my variable: and press Enter, you’ll see a prompt to enter the variable value.

It’s also possible to perform math with Set using the /A command line switch. There is a whole list of standard math notations you can use. Type Set /? and press Enter to see them all. If you write application code at all, you’ll recognize the standard symbols. For example, if you want to increment the value of a variable each time something happens, you can use the += operator. Type Set /A MyVariable+=1 and press Enter to see how this works. The first time you make the call, MyVariable will equal 1. However, on each succeeding call, the value will increment by 1 (for values of 2, 3, and so on).

Environment variables support expansion and you can see this work using the Echo command. For example, if you type Echo %MyVariable%, you see the value of MyVariable.

However, you might not want the entire value of MyVariable. Newer versions of the command prompt support substrings. The variable name is followed by a :~, the beginning position, a comma, and the ending position. For example, if you place Hello World in MyVariable, and then type Echo %MyVariable:~0,5% and press Enter, you see Hello as the output, not Hello World. Adding a negative sign causes the expansion to occur from the end of the string. For example, if you type Echo %MyVariable:~-5% and press Enter, you see World as the output.

The Set command is a valuable addition to both the administrator’s and programmer’s toolkit because it lets you set environment variables temporarily. The Set command figures prominently in batch file processing and also provides configuration options for specific needs. Let me know about your environment variable questions as they pertain to my books at [email protected].

A Windows Security Alert, Courtesy of Samsung

I’ve gotten used to a whole lot of silly vendor tricks over the years. Just about every vendor I’ve worked with has done something completely idiotic, just to cause the other guy woe. The user always ends up hurt. Readers of Administering Windows Server 2008 Server Core, Microsoft Windows Command Line Administration Instant Reference, and Windows 8 for Dummies Quick Reference need to be aware that according to a ComputerWorld article, Samsung has turned off Windows Update. The worrisome part of all this is that there is apparently an executable to turn the support off, but not another executable to turn support back on. Sites, such as engadget, are recommending you perform a clean install of Windows on your computer to get rid of the problem.

The whole issue seems to revolve around Samsung being worried that Microsoft’s updates will interfere with Samsung’s updates of its software. The result could be that the system won’t work. Phrases, such as “could be” and “might not”, always bother me. Samsung must not have tested the problem fully or they would have had a more positive and straightforward comment to make when asked about the problem. The point is that the user loses. Advice such as telling users they must reinstall Windows from scratch to get rid of the problem sounds just dandy until you figure out that most users can’t perform this task, so they’ll be out extra money getting someone else to do the job or we’ll all face the issues that happen when updates don’t occur. It’s not as if the Internet really requires yet more zombies (computers under hacker control)—we have no lack of them now.

A similar problem occurred not long ago when Lenovo thought it would be a good idea to pre-install the Superfish adware on the computers it put out. Most computer vendors add bloatware to their systems, which really does make it a good idea to perform a clean install when you buy a new system, but purposely adding adware seems a bit deranged to me. Lenovo later apologized and fixed the problem, but the point is that they made the mistake in the first place.

Some of my readers have asked why so many of my books include installation instructions or at least pointers to the installation instructions. The answer is that vendors keep doing things that make me shake my head and wonder just what they were thinking about. When you buy a new system from someone, perform a clean install of the operating system to get rid of the bloatware or have someone else do it for you. If you choose to keep the pre-installed operating system in place, make sure you research any oddities of the installation (such as turning off Windows Update). Otherwise, you might end up with a situation where Windows Update simply doesn’t do the job because someone told it not to. Let me know your thoughts on pre-installed software, bloatware, and vendors who seem completely clueless at [email protected].

Story Update!

According to a ComputerWorld article, Samsung will end the practice of disabling Windows Update. Of course, one has to wonder why they did it in the first place. If you have one of the systems that disabled Windows Update, a patch will restore the system to perform the required updates.

 

Dealing with Acronyms and Abbreviations

My books are packed with acronyms and abbreviations, and readers complain about them all the time. An acronym is a series of letters that shorten a term and you can say. For example, Language INtegrated Query (LINQ) is pronounced “link” so it counts as an acronym. An abbreviation is a shortened version of a term or phrase. For example, MicroSoft Developer Network (MSDN) is an abbreviation because you can’t say the term and must instead say each letter individually. Whether the term is an acronym or an abbreviation, I usually try to define it once every chapter. However, some truly common terms are only defined once in a book and if a term is considered universally known outside computer circles, such as CPU (for Central Processing Unit), I don’t define it at all.

Unfortunately, making an assumption can be a dangerous thing. I try to err on the side of defining terms too often so that readers can gain maximum benefit from my books with the least amount of effort. However, even making my best efforts, there are times when you might find an acronym or abbreviation that you simply don’t understand in one of my books. When this happens, you can always contact me at [email protected] and I’ll be happy to define it for you. My goal is to ensure you have a great reading experience and that you discover everything possible about the topic at hand.

Some people prefer to do things for themselves. Hands on learning produces the best results for them and I do understand the need to address the learning methods each person uses with greatest ease. In this case, you have other options for finding the term you need defined. These sites will provide you with common terms used in my books (depending on the book, you may need to use more than one site):

Of course, there are many other fine online references, but these references should provide what you need in most cases. The worst case scenario would be to use the acronym or abbreviation without really knowing what it means. I encounter this problem all too often. Readers will contact me with a question that I truly can’t understand because of a misused term. Knowing what terms mean is an essential part of clear communication. Given that most of my communication is through e-mail, clear communication saves time and effort for everyone involved.

The question I get asked relatively often about acronyms and abbreviations is why the computer community uses them at all. After all, they’re confusing. Typing the full term every time you wanted to use it would be cumbersome at the least and error prone as well. Using a shorter term means concise communication. Using the terms correctly means precise communication. Every trade has its jargon and those jargon terms were created in order to ensure that two people communicating about a topic could do so in the most precise manner possible. I’ve discussed the need for jargon in the past in posts such as Power Words.

 

Your Security is an Illusion

I receive a number of queries about security from administrators and users every month, and many of these questions have links to all sorts of security issues that have occurred recently-everything from National Security Agency (NSA) spying to the Target security breach (incidentally, a number of other businesses have been attacked in the same manner). The fact of the matter is that books such as Administering Windows Server 2008 Server Core, Microsoft Windows Command Line Administration Instant Reference, and Windows 8 for Dummies Quick Reference have been telling you all along that security is a matter of vigilance-that software will never do the job alone. Even so, readers keep sending requests for some sort of magic bullet that will allay all their fears and make the task of security automatic.

Maintaining a reasonably secure system is a matter of observing personal, data, and system-wide best practices, something that SeedboxCo.net could help with if you’re unsure about how to go about it. Many other authors have listed these best practices in the past, but here are some of the techniques that people fail to use most often:

  • Use complex passwords that are easy to remember so you don’t need to write them down-consider using a passphrase whenever possible.
  • Change your password reasonably often and don’t rely on the same set of passwords all the time.
  • Keep your passwords secret so that no one else can abuse them.
  • Encrypt your data.
  • Perform local data backups regularly.
  • Ensure your applications remain updated with the latest security fixes.
  • Update your system as needed to ensure it provides a full set of modern security features.
  • Install security applications that check the incoming and outgoing flow of data, and block anything that looks remotely dangerous.
  • Check your system regularly for any files, folders, software, or other items that look out of place.


This list doesn’t even include some of the common user foibles, such as opening e-mail from parties they don’t know. In addition, none of these techniques are automated. You have to perform the manually in order to get the benefits they provide. Yes, it’s true that some of the techniques are automated once you start them, but you still have to start them. For example, installing security software will automatically monitor the data flow on your system, but you still have to install the security software manually.

Even with all of these security measures in place, someone who is truly determined can break into your system. You should simply count on it happening at some point, even if you’re incredibly careful. When a security breach does occur, you need to have a contingency plan in place.

Any good contingency plan will include a method of evaluating the damage caused by the security breach. You need to know just what was compromised and what the fallout of the compromise will be. Make sure that you are open and honest with your customers at this time as failure to do so can lead to other consequences. Silencing employees who speak out is even worse – you don’t want to juggle a legal fight with a whistleblower lawyer at the same time as cleaning up a data breach – so remain open to conversation at this time. Even individuals experience fallout from security breaches, such as identity theft. Once the damage is evaluated, you need a method for fixing the problems it has caused. In some cases, you may actually have to format the drive and start from scratch, which is where that data backup is going to become critical.

There is no magic bullet when it comes to security. Over the years I’ve searched, in vain, for a magic bullet and it isn’t even possible to conceive of one. Therefore, it’s the user and administrator who are best prepared for the eventuality of spying and security breaches that are in the best position to handle it later. Let me know your thoughts on security at [email protected].

Understanding the Maturing of the Command Line

A number of people have asked me why I’ve written several different command line reference books. The answer is that each book serves a different market. Serving reader needs is a quest of mine. As reader needs change, I also change my books to better meet those needs. The command line may seem static, but reader needs have changed over the years because of the way in which the command line is perceived and the new commands added to it.

The most popular of the set, Windows Command-Line Administration Instant Reference, provides the reader with quick access to the most commonly used commands. In addition, this book emphasize examples over documentation, so you see how to use a command, but don’t necessarily get every detail about it (only those that are used most often). This book is mainly designed to assist administrators. With this group in mind, the book also provides a good overview of batch files and scripting. The point is to provide something small that an administrator can easily carry around.

A second command line reference, Administering Windows Server 2008 Server Core, is designed to meet the needs of those who use Microsoft’s Spartan Server Core operating system. The book includes a number of special features for this audience, such as instructions on getting hard to install software to work in this environment. This is also the only book that discusses how to use Mono to overcome .NET Framework limitations in this environment. Even though the title specifies Windows Server 2008 Server Core, the book has also been tested with Windows Server 2012 Server Core. The point of this book is to allow you to get all of the speed, reliability, and security benefits of Server Core installations without all of the hassle that most administrators face.

My third command line reference, Windows Administration at the Command Line for Windows Vista, Windows 2003, Windows XP, and Windows 2000, serves the general needs of administrators and power users. This book is intended to help anyone use the command line more efficiently. It provides a little more hand holding and considerable more detail about all of the available commands than my other two books. This is also the only book that discusses PowerShell.

The PowerShell portion of this third book has received a lot more attention as of late. Microsoft is making a much stronger emphasis on this new version of the command line, so I’m glad I included it in my book. One of the strong suites of this book is that it not only discusses documented commands, but many undocumented commands as well (with the appropriate caveats, of course).

No matter which version of my command line reference you use, I’m always here to answer your questions about my books. How do you interact with the command line? Has PowerShell taken a more prominent role in the way you do your work? Let me know at [email protected].

 

Limitations of the FindStr Utility

Readers have noted that I use the FindStr utility quite often. This utility is documented in both Windows Command-Line Administration Instant Reference and Administering Windows Server 2008 Server Core (and also appears a host of my other books). At the time I wrote that documentation, I had no idea of how much comment this particular utility would generate. I’ve written a number of posts about it, including Accessing Sample Database Data (Part 3), Understanding Line-, Token-, and String-Based Command Line Utilities, Using the FindStr Utility to Locate Errors in Visual Studio, and Regular Expressions with FindStr. It might be possible that people think that this utility is infallible, but it most certainly has limits. Of course, the FindStr utility is line-based and I’ve already documented that limitation. However, it has other limitations as well.

The most important limitation you must consider is how FindStr works. This utility works with raw files. So, you can use it to look inside executable files and locate those produced by a specific organization as long as the file contains unencrypted data. When an executable relies on obfuscation or other techniques to render the content less viewable by competitors, the strings that you normally locate using FindStr might become mangled as well—making them invisible to the utility. In practice, this particular problem rarely happens, but you need to be aware that it does happen and very likely will happen when the executable file’s creator has something to hide (think virus).

Another problem is that FindStr can’t look inside archives or other processed data. For example, you can’t look inside a .ZIP file and hope to locate that missing file. You might initially think that there is a way around this problem by using the functionality provided in Windows 7 and newer versions of Windows to look inside archive files and treat them as folders. However, this functionality only exists within Windows Explorer. You can’t open a command prompt inside an archive file and use FindStr with it.

Recently, a reader had written me about his Office installation. Previously, he had used FindStr to locate specific files based on their content—sometimes using content that wasn’t searchable in other ways. This feature suddenly stopped working and the reader wondered why. It turns out that .DOC files are raw, while .DOCX files are archives. Change the extension of a .DOCX file to .ZIP and you’ll suddenly find that your ZIP file utilities work great with it. Old Office files work well with FindStr—new files only work if you save them in .DOC format.

Another reader wrote to ask about network drives. It seems that the reader was having a problem locating files on a network drive unless the drive was mapped. This actually isn’t a limitation, but you do have to think about what you want to do. Let’s say you’re looking for a series of .DOC files on the C drive (with a shared name of Drive C) of a server named WinServer in the WinWord folder that contain the word Java in them. The command would look like this: FindStr /m /s “Java” “\\WinServer\Drive C\WinWord\*.doc”. When using network drives, you must include the server name, the share name, the path, and the file specification as part of the command. Otherwise, FindStr won’t work. What I have found though is that FindStr works best with Windows servers. If you try to use it with another server type, you might experience problems because FindStr won’t know how to navigate the directory structure.

There is a real limit on the length of your search string. Another reader wrote with this immense search string and wondered why FindStr was complaining about it. The utility appears to have a search string length limit of 127 characters (found through experimentation and not documented—your experience may differ). The workaround is to find a shorter search string or to perform multiple searches (refining the search by creating a more detailed file specification). If you can’t use either workaround, then you need to write an application using something like VBScript to perform the task.

These are the questions that readers have asked most about. Of course, I want to hear your question about limitations as well. If you encounter some strange FindStr behavior that affects my book’s content in some way, please be sure to write at [email protected].

 

Quotas Revisited for Windows XP

The other day I provided a post about quotas that contained a simple three step process for turning quota monitoring on and logging quota events, without actually enforcing the quota. It turns out that the process works just fine with Vista and Windows 7, but it doesn’t quite work with Windows XP. Microsoft made a fix between operating systems and didn’t mention the change to anyone. Of course, this is an old story with Microsoft. You have to watch carefully because you might miss a fix and find that your perfectly functioning batch file or script suddenly stops working.

It turns out that Windows XP does things a little differently. When you execute the FSUtil Quota Track C: command, you get the expected result; tracking is enabled. The next step is to turn on exception logging using the WMIC QuotaSetting Where Caption=”C:” Set ExceededNotification=True command, which also works as expected. However, when you execute the WMIC QuotaSetting Where Caption=”C:” Set WarningExceededNotification=True command to turn on warning logging, suddenly, the exception logging is turned off. Likewise, if you were to reverse the order of the two WMIC commands, you’d find that warning logging is turned off.

Fortunately, there is a fix to this problem and it’s a very odd fix indeed. In order to enable tracking and turn on both levels of logging, you need to follow this order in Windows XP:

  1. FSUtil Quota Track C:
  2. WMIC QuotaSetting Where Caption=”C:” Set ExceededNotification=True
  3. WMIC QuotaSetting Where Caption=”C:” Set ExceededNotification=True

That’s right, you issue the exception logging command twice and you’ll find that both logging check boxes are checked. Microsoft fixed this particular error between Windows XP and Vista, but I can’t find any source that tells me about the fix. If you find one, feel free to contact me at [email protected].

Regular Expressions with FindStr

Regular expressions are a powerful feature of the FindStr utility. However, they can also prove frustrating to use in some cases because the documentation Microsoft provides is lacking in good examples and difficult to follow. You can see some usage instructions for FindStr starting on page 82 of the Windows Command-Line Administration Instant Reference .

A reader recently commented that there is a problem with the dollar sign ($) regular expression. It must actually appear after the search term to be useful. Of course, the problem is creating a test file to sufficiently check the use of the regular expressions, so I came up with this test file:

TestFile

Now, let’s perform some tests with it.  Here is the result of some tests
that I performed using this test file and FindStr regular expressions:

TestResults

The first test case shows what happens when you try
the command on page 82 of the book.  It appears to work, but you’ll see
in a moment that it actually doesn’t.  Let’s take the two parts of the
regular expression apart.  Using FindStr “^Hello” *.TXT seems to work just fine.  However, the command FindStr “$World” *.TXT doesn’t produce any output.
Only when the $ appears after World does the command produce an
output.  Consequently, page 82 should show the rather counterintuitive
command, FindStr “^Hello World$” *.TXT to produce the correct output.

It’s also important to be careful about making generalizations when
using FindStr. For example, when working with the test file originally
shown in this example, the FindStr /B /C:”Hello World” *.TXT command produces the same output as FindStr “^Hello” *.TXT as shown here:

TestResults2

If you change the test file like this though:

TestFile2

you’ll see these results:

TestResults3

As you can see, you must exercise care when using FindStr to obtain the
desired results.  What other odd things have you noticed when using
regular expressions with FindStr?  Add a comment here or write me at [email protected] to let me know.