Re: [PLUG] Anyone Experienced with C Pointers?

I'd say that you have a basic understanding of memory allocation, but that's not really the same as asking about C pointers.

The stack is used for statically allocated memory - things like declared variables, function parameters, etc.

The heap is used for dynamically allocated memory - this memory is allocated at run-time - calls like malloc and calloc are allocating memory from the heap. This might be used when a variable's size is not known at compile-time (IE: an array of some sort whose capacity is based off of some kind of input).

When you allocate memory from the heap, you'll get a pointer (an address) back to that memory. You then access that memory through operations on that pointer.

This is all pretty high level - does it answer your question at all?

-----Original Message-----
From: Ron Guilmet <ronpguilmet@gmail.com>
To: Philadelphia Linux User's Group Discussion List <plug@lists.phillylinux.org>
Sent: Fri, Oct 5, 2018 5:19 pm
Subject: [PLUG] Anyone Experienced with C Pointers?

I have been working with writing a device driver for my HP laptop. The

wireless doesn't work well. I think it is an antenna selection issue.

The laptop any distro shows about 10% on the wifi even when you are 10

feet away.

That said, I've been refreshing myself with C. Pointers is one of those

areas that seem to give everyone a hard road to hoe. Sometimes a high

overview helps. I wanted to present what my understanding is, and I was

hoping someone could elaborate on it.

My understanding of pointer use is the following. I understand there

are different sections of memory. A section for the code, a section for

the running app called the stack, and then your free or available

memory called the heap. I understand that if the running program needs

more memory, it has to access the heap, and the heap can only be

addressed by memory addresses. Does that sound about right?

Rom

___________________________________________________________________________

Philadelphia Linux Users Group -- http://www.phillylinux.org

Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce

General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug