The tradition for successfully exiting a command line program is to use return 0; or, as I write it, return(0);. Zero is the OK value, meaning a program exited cleanly. Other values returned represent specific conditions, not necessarily errors, but information that can be communicated to the operating system or some other program.
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As a mid-level language, C has just as many positives as negatives with regards to accessing memory. One of the biggest negatives is C’s unflinching capability to access data that doesn’t exist.
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The C99 standard added a feature to dimension an array on-the-fly. The official term is variable length array or VLA. And while you might think everyone would love it, they don’t.
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This month’s Exercise was inspired by a program I recall from years ago called The Drunk and the Lamppost. It’s not the classic joke, but an examination of random movements and probability.
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The best way to declare a string literal in your code is to use array notation, like this:
char string[] = "I am some sort of interesting string.\n";
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The chessboard is empty. In the center is the king. He can move only one square at a time, but in any direction — or he can choose not to move at all. How many turns would it take him, moving randomly, to exit the chessboard?
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Many programs rely upon external files to store data. When the file is missing, or not where it should be, the fopen() function returns a NULL pointer, which your code can act upon. Or, you can pre-check for the file’s existence by using the access() function.
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Have you ever had your C code run amok and had to press Ctrl+C to cancel?
Yeah, I’ve never had that happen to me either.
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A specific command to terminate a program was popular with programming languages long ago. For example, in BASIC you had the END command, which exited a program. For unusual circumstances, you could use the STOP command. It was the abnormal termination command, which stopped the program and also generated a “Break in line” message (in GW Basic). I’m sure other early languages also had commands to bail out of a program, and modern languages are the same.
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The nifty thing about this month’s Exercise is that so many solutions are available. In fact, I found the challenge engaging because I kept trying to think of other ways to solve the puzzle.
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