Next to enum, one of the more curious C language keywords is union. It’s tremendously unpopular. I would offer that it’s also not needed, but no one is talking about deprecating it.
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To Form a More Perfect union
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Category Archives: Lesson
The Mysterious enum Keyword
They’re the orphan keywords, urchins, unwanted, unused, unloved. Of the 32 C language keywords, a handful are seldom used. These include: auto, enum, register, union, and volatile.
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A Fork in Your Code
All of the code I’ve written in my books as well as demonstrated on this blog has been single-tasking: The program runs as one process, does one thing, in order, and then terminates. With this Lesson, that streak ends.
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Know Your Process
Program. Software. Application. Process. These are all terms that describe different aspects of a similar thing.
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The Marvelous popen() Function
To launch and run another program from within your code, use the system() function. When your code must examine or save that program’s output, use the popen() function.
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Execute and Leave
The system() function allows you to run one program from within another. If it’s your desire to launch another program and have your program quit, you can immediately follow system() with an exit() function. Or you can go out of your way and use the oddball execl() function.
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The Joys of Iteration
Suppose that you’re testing code and need to run a program six times in a row. You could keep repeating the program, running it multiple times, but why not write a utility that does the same thing? That would be a good and practical way to put the system() function to work.
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Hello, System
One thing that continues to puzzle me about learning the C language is how frequently beginners use the system() function. Is it a crutch? Is it a necessity? What’s the allure of this function that makes it show up in beginner code?
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Before You Say Goodbye . . .
The standard C library contains a lot of interesting and unusual routines. Some can really put the fun into function. One of them I’ve rarely used, but which can be extremely handy, is atexit().
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Build Your Own strcasestr() Function
I was a bit surprised the other day. I’d written code on my Macintosh and tried to run it on the PC. Because I usually write generic stuff, I figured that the code would compile and run on both systems. But it didn’t compile.
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