> Arrays in C have length information. Pointers do not.

This is 100% correct. The parent of the parent is confused (or is just using terminology incorrectly) as are the current siblings to my comment.

One post claims pointers carry length information so that free works. This has nothing to do with pointers, it has to do with the implementation of malloc and friends. It's only a promise of a successful malloc that you can free, nothing to do with the pointer other than it was returned by malloc. Pointers can point to all sorts of things, the only information they intrinsically have are the type of the object they point to and its address.

Two posts claim a function can return an array of bytes. This is impossible in C. You can't return an array of bytes. You can return a pointer that might point into a continuous sequence of bytes. You could also return a struct whose member is an array, but that's rarely done. When you return (or pass) what looks like an array syntactically, it is converted to a pointer to its first element.

Arrays, on the other hand, always carry length information via the sizeof operator. A special hand waving case would be you could define a pointer to an array (not a pointer to the first element of an array), so in effect the length is contained within the pointer type. E.g. char (*foo)[42] declared foo as a pointer to an array of char with length 42.

> Arrays in C have length information. Pointers do not.

Sure, but they don't carry that length information when being returned from a function.

Pity that they decay into pointers all the time.

So that is pretty much worthless outside the current scope where they were declared.

> Arrays in C have length information.

Not in any sense that is actually useful to the programmer, at runtime at least. You cannot ask an array how big it is.

Pointers actually do have length information as well, otherwise free() would not work. But its the same deal with arrays - there is no way to access it outside of compile time constants, if those are even present.