Hi everybody, I'm doing a simple client server communication system.

The client have to send in a TCP socket a couple of strings and the server receive them, then have to search in a buffer if a category is similar to even just one of the strings sent by the client, and put them in a similar buffer.

The buffer of the server is done in this way:

#define SIZE 10

struct content {
	char idCategory[50];
	int timestamp;
};

struct buffers {
	struct content* locations;
	int size;
	int i_get;
	int i_put;
};

struct buffers buffer;

//function that inizialize an empty buffer

void create_empty_buffer() {
	buffer.size = SIZE;
	buffer.locations = malloc (sizeof(struct content)*buffer.size);
	buffer.i_get=0;
	buffer.i_put=0;
	int i;
	for (i=0;i<buffer.size;i++) {
		strcpy(buffer.locations[i].idCategory,"void");
		buffer.locations[i].timestamp=0;

	}
}

The buffer where the server copy the content to give it to the client is:

struct buffersClient {
	int size;
	struct content* locations;
};

Then in the server I have the function that make the copy and return it as type struct buffersClient b.

char c[5];
struct buffersClient reply;

reply=getContent(c);

//then in the function getContent

struct buffersClient getContent (char* c) {

    struct buffersClient b;
    b.locations=malloc(sizeof(struct bando)*SIZE);
	
	int j;
	int k;
	k=0;
	
		for (j=0; j<buffer.size;j++){
			if (strcmp(c,buffer.locations[j].idCategory)==0) {
				b.locations[k]=buffer.locations[j];
				k++;
			}
		}

	
    return b;
}

// then in the server:
write(sockmsg,&reply,sizeof(reply));

// in the client

 struct buffersClient result;
 read(sock,&result, sizeof(result));

This works in the server side (I can read reply) but in the client give me segmentation fault if I try to read the result content such as: result.locations[0].idCategory.
If I make the malloc in both client and server the same: segmentation fault. If I make the malloc only in the client: segmentation fault for server..

How can I do?

Thank you in advance.

Edited 6 Years Ago by samp4ever: n/a

You can't send pointers through a socket connection. Pointer addresses are only valid within its own address space.

Thank you for your reply gerard4143.

It is an exercise so I'm trying it in the same machine, client in a terminal and server with another terminal shell.

If I've understood what you mean, I can't send the buffersClient reply because it contains a content* locations inside.

So is not possible through socket sending a data set all togheter? I need to send more object struct content all togheter, how can I do?

Thank you again.
--

EDIT: thank you, solved with struct content locations;

Edited 6 Years Ago by samp4ever: solved

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