It’s nuts. All through your C training when you learned about arrays, you were taught the format: array[x] where array is the name of the array and x is the element number. But this expression can also be written as x[array].
Mind. Blown.
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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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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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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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With the dawn of the new year, and my reflection upon the Clock program I blogged about recently, I’ve been thinking about time. Specifically, the time_t data type used with various C library time functions. Can this value contain negative time?
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My clock program is almost complete! It generates the current time as output and it updates the current time every minute. The only step remaining is to synchronize the program’s output with the system time. I want to ensure that when the system reads :00 seconds that the program ticks over to the next minute.
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