When I’m working with programming students, I usually write a quick Makefile. Only a few lines long, this file allows us to recompile code on the command line just by typing “make”. In this post, we’ll skip over all the details of writing complex Makefiles. Instead, we’ll see how to slap together a rudimentary Makefile in seconds — one that will save us time while we’re working on an assignment.
Tag: C
Using C Defines to Change Constants During Compilation
It’s not uncommon that we find ourselves repeatedly editing our code and recompiling, just to change the value of a constant. In C, though, we can skip the step where we edit the source file to change the constant’s value. Instead, we can use a combination of the #define and #ifndef preprocessor directives to change its value directly on the command line at compile-time.
Exiting on malloc(3) Failure
To the annoyance of many students learning C programming, allocating memory by calling malloc(3) can fail. When it does, malloc(3) will return NULL. But, what should our program do when a call to malloc(3) fails? The question that today’s blog post explores is: when is it okay for our program to exit(3) — that is, simply terminate — because of a memory-allocation failure?
Better printf(3) Debugging in C
In today’s blog post, we’ll look at one way to improve printf(3) and fprintf(3) debugging in C. Namely, let’s make it so our printf(3) debugging outputs include the name of the source code file, the function name, and the line number where the output happens. Debugging with printf(3) is fast and easy, and it’s not going anywhere; so, let’s just make its output more useful.
Constant Pointers in C: Reading Right to Left
The “const” keyword in the C programming language, when applied to pointers, can be quite confusing to read. How do you read a variable declaration like “const char *const *const p”? This blog post explains how to read these declarations, and demonstrates the technique of reading them from right to left.