Is it best to minimize using pointers in C?

Question

I think most people would agree that pointers are a major source of bugs in C programs (if not the greatest source of bugs). Other languages drop pointers entirely for this reason. When working in C, then, would it be best to avoid using pointers whenever practicable? For example, I recently wrote a function like this:

void split (char *record, char *delim,
            int numfields, int fieldmax,
            char result[numfields][fieldmax]);

While not as versatile as a dynamically allocated variable, in that it requires the programmer to know the number of fields in advance and anything over fieldmax is truncated (which is sometimes acceptable), it eliminates the need for memory management, and the potential for memory corruption. I think this is a pretty good trade, but I was wondering what the opinions of other programmers on this were.

Answer 1

Other languages don't "drop pointers entirely," they just restrict what you can do with them, give them a syntax that looks like non-pointer variables, handle some operations on them behind the scenes, and call them something else, like a reference or object. If you ever have to make a distinction between assigning a copy of something or not, you are dealing with pointers.

With the exception of programming paradigms that pass everything by copy, with obvious performance implications, the use of pointers is unavoidable in all but the simplest of programs. By all means, use stack variables where it makes sense, but if you try to avoid pointers too much, you will introduce a whole different breed of potential bugs.

Answer 2

In my opinion, it doesn't make any sense to use C and want to avoid pointers. If you do so, then you'd better use another language.

Pointers are unavoidable in C. This is what make C so powerfull and also what make C a pain in the ass sometime. C is meant to be used with pointers.

Arrays are pointers, functions are pointers, memory allocation work through pointers, and so on. Take advantage of that or change language.

Answer 3

Those char* should really be const, unless you actually meant a pointer to one single character, which I find to be quite unlikely. Apart from that, pointers are the reason C is so fast- they're extremely efficient. What else are you going to do, copy everything around everywhere? The ability to alias any variable at any time is risky, but it's also very powerful.

If you don't like bugs, and you still like performance, then upgrade to C++. It's vastly less buggy when written with adherence to it's most basic principles and can be faster than C, and is certainly no slower in the general case.

Answer 4

Good luck using the standard runtime or any third-party libraries. If you mean you want to avoid pointer manipulation then you might have a chance, but I don't think you'll gain any real benefit. It's the nature of the beast; if you want protection from pointer errors, then you'd be better off using a different language.

Answer 5

The power of C comes from the fact that underline data storage is transparent to use. It is not really about pointers, it is more about working directly on hardware while still being a general purpose code.

While this may be of no virtue in many cases, in that case, we don't need to drop pointers from C, we need to drop C from development.

In my opinion, in your earlier version, you are NOT avoiding pointers. I can always supply an already corrupt (or free()ed) pointer as *record and everything will be doomed!

The core issue, though, is not really pointers! I have seen so many people don't get it right in the beginning, but even after having reasonable number of project experience, some get it, some fear it. I cann't say authoritatively, but those who have some basic exposure (introduction) to microprocessor architecture and/or OS basics, don't quite face that much trouble. It is the essence of how the machines work and C translates it in a very transparent way on higher level. If you ever fear pointers in C, try work on this background knowledge and lot of practice; things should work smooth. I don't quite believe that one should ever fear C or its' pointers. If you have the fear, there is always a way to get over it and then start enjoying pointers in C.

Answer 6

In principle you're right that only using pointers when necessary will result in fewer bugs. However, in C, almost all of the time, pointers ARE necessary.

For instance, I may be wrong, but I don't think your code sample works: I don't think the function can receive a dynamic array as an argument, so it will have to use "numfields" and "fieldmax" to calculate where to write the data -- which will scribble over random memory if the wrong sizes are passed.

And most of the time, deciding the return size in advance will be difficult. If you want to avoid pointer bugs, use C++, and use pointers only when you need to.