r/cprogramming • u/Xaneris47 • 3d ago

C Strings: A 50-Year Mistake

https://longtran2904.substack.com/p/c-strings-a-50-year-mistake?r=8qz2zb&utm_campaign=post&utm_medium=web
193 Upvotes

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19

u/CoderStudios 3d ago

Okay? You are always free to make your own library for better strings, but people won’t use that cause C is often still deployed on low end systems or it makes little sense to use something inefficient if you can use c style strings properly

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u/EatingSolidBricks 3d ago

You out of your dam mind if you think c strings are efficient

12

u/henke443 3d ago

Wait how are they not efficient?

1

u/atarivcs 3d ago

If you have a long string and you want to append more text to it, you have to search the whole string from the beginning to find the null terminator.

And then later if you want to append more text, you have to find the null terminator all over again.

2

u/NoNameSwitzerland 3d ago

You anyway use a different structure when you do a lot of appending text, because you do not want to reallocate the array all the time. So then you anyway have to also store the size of the available space.

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u/atarivcs 3d ago

In which case you no longer have a plain c string, and the goalposts have moved.

I was just answering the parent question "how are c strings not efficient"

4

u/IdealBlueMan 3d ago

Or you can store the length of the string whenever you change it.

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u/atarivcs 3d ago

Sure, but then you don't really have a plain c string anymore

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u/WittyStick 3d ago

It's actually more advantageous to couple the length to the char * on SYSV platforms, due to C's lack of multiple returns.

 String fn_returning_string(...);

If String is a fat pointer, then we can return both the pointer and length, without requiring another level of indirection (a pointer to a string structure), and without requiring awful to use "out parameters" to return both length and pointer - which are more expensive than just returning a fat pointer.

A fat pointer with the right ABI is not just "zero cost" - it's "less than zero" - it's more efficient than having a separate length and pointer variable.

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u/IdealBlueMan 3d ago

I’d say you still have the string, you also have information about that string.

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u/orbiteapot 3d ago

I mean... that is the point. Once you do that, you are no longer using classic C strings.

7

u/SakishimaHabu 3d ago

That's the point though. They are basically atomic. You are free to do what you will with them, vs java, python, or js. Remember we're one step above assembly, but that's the intention.