Thread: File Server Help

Actually wait... if it's sorted, you couldn't, because it's a list. But with a sorted array you could.

How do you say I can do it with an array? cause I can't have a fixed array if I want to support multiple connections or can I?

Why do you assume you can't do this with a fixed array? You could also dynamically resize an array if necessary. I recommend against the linked lists for the reasons stated in my previous post. You aren't doing that many connections anyway. You aren't writing a server comparable to google's.

Right. I'd just stick with an array and a loop to find the elements. Keep it simple.

Can you give me an example of how can i resize the array each time I need to do it? Well.. I'm trying to do this program to communicate some offices and save all the files into a server.. I might need a big array..

You can use realloc(). With any sort of web application I typically allocate large pools anyway. I prefer to manage my own memory. That not withstanding, why not just make a 1MB buffer or something for your arrays? I doubt you will need more than 1MB (1048576 bytes).

[edit]I don't know what it is with people new to programming. Memory is a luxury that we have to work with in this day and age. Nowadays if you need a 15MB buffer, its not so outlandish. Don't be afraid of allocating chunks of memory that are 10,000 * sizeof YourClass. In the grand scheme of things that usually ends up being like 40k of memory...[/edit]

search the board.

Indent your code.

http://www.eskimo.com/~scs/cclass/notes/sx11c.html

Is it ok like this?
Well.. I'm still not understanding how can I create or resize an array using realloc(), I mean, I create a pointer, or I give it a bigger size taking in consideration the size of my struct.. how the program knows that I'm creating an array?

Code:

struct _fileinfo {
	FILE *file;
	int parts;
	int totalparts;
};

int totalconnections;

void memoryfunct() {
	struct _fileinfo *arr;
	realloc(arr, (totalconnections * sizeof(*arr)));
	arr[i].file="fopen(filepath, "ab");
..
..
}

Because you used realloc. What else is it going to be? (Answer: a single object, but if you try hard enough, you can think of that as a 1-element "array". I'm putting "array" in quotes because you are not creating a thing of array type, but you are creating a thing that you can use index[notation] with.)

>Is it ok like this?

no. read the link.

I need a little help understanding the code..

Code:

#define MAXLINE 100

char line[MAXLINE];
int *ip;
int nalloc, nitems;

nalloc = 100; -> //100..
ip = malloc(nalloc * sizeof(int));/* initial allocation */ -> // Why is is multiplying the size with 100? is it the same as "someinteger[100]" ?
if(ip == NULL)
	{
	printf("out of memory\n");
	exit(1);
	}

And about this..

Code:

nitems = 0;

while(getline(line, MAXLINE) != EOF)
	{
	if(nitems >= nalloc)
		{				/* increase allocation */
		int *newp;
		nalloc += 100;
		newp = realloc(ip, nalloc * sizeof(int));  // -> Is it adding 200 more integers to the arr?
		if(newp == NULL)
			{
			printf("out of memory\n");
			exit(1);
			}
		ip = newp;
		}

	ip[nitems++] = atoi(line); -> // what does ip[nitems++] is supposed to do?
	}