Question

Using Linux system calls open and read. The read call accepts 3 parameters

read(File descriptor, Buffer array, Size of the buffer array);

My question is related to the argument #3. Suppose I have multiple text files that I want to read into my buffer array. But as far as I know C doesn’t have something like Vector or ArrayList or any other structure with a dynamic size.

Is there an easy way to calculate the size of the file so I know how much space should I allocate for my char array?

Answer 1

You could also stat() the file to determine its size and then call mmap() on it. Your file will appear as an “array” without the need to malloc() memory.