Simulation of a server and clients

Hi everyone, Iam new in C programming and I need some help solving this program, this dosent have to do anything with network programming. This is just basically a C language simulation program between clients and a server. There is a function for server and a function for clients that i need to do... this is where iam stuck i need to apply queues but i need to know where? can some one give me hints...

this is the program requirements are:

Code:

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In c programming create a Server process and a Client process.
The Client will randomly generate some text and send it to the Server
the Server will then echo the text to all Clients including the name of
the Client sending the message. This will then be displayed by each of
the Clients that are attached to the Server.
Server should continuously loop and accept messages from Clients
and then echo them. Each client gets a unique name which will be passed to
the server at the time when the connection is established.

Run one server and ten clients for at least 100 distinct messages from all clients.

Typical output may look like:
Client1 sends: abba
Client3 receives: From Client1: abba
Client4 receives: From Client1: abba
etc... smile

or... if you wish...
Client1 sends: abba
Client3 receives: Client1> abba
Client4 receives: Client1> abba
etc... smile

(remember that more than one message may pile up on one client; therefore, you need
to allow a queue for each client... similarily, for the server)

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This is what i have so far iam in stage 0.5 right now. Can some of you give me some hints in how to continue develop this program. Thank you very much

Code:

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#include<stdio.h>
main()
//void client;
{
  char message[30];
  printf("THE SIMULATION OF A CLIENT AND SERVENT PROGRAM\n\n");
  printf("Client1 Sends: ");
  scanf("%s",&message);
  printf("Client2 Receives: %s",message);

  //void client()
                        //{


                //}
 
  //void server()
                        //{


                //}
       
return 0;
}

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Search google about Winsocks.

Well as you're doing a simulation of a network rather than using a real network...

> this is where iam stuck i need to apply queues but i need to know where?
How about between the client and the server?

Before you even do any of that, just read up on queues and how they work (plenty of examples on this forum).

Each client has an input queue, and the server has an input queue.
sending a message writes a message to the input queue of the thing you're sending to
receiving a message reads a message from your own input queue.

Most important of all, build it up in stages. Don't try and write the whole thing in one go.

Iam new in C but this is what i have so far. This program is a simulation it dosent have to be real. This program is to get the concept between clients and servers and how they work. I need some help with this code i want to make it as simple as posible. Please feel free to give some comments in how to improve this code.

Thanks

Code:

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#include <stdio.h>  // in/out function header
#include <string.h>  // string function header
#include <stdlib.h>  // malloc()

void enter(void);
void list(void);
void q_store(char *ptr);
int store = 0;        // next storage position in queue[]
int retrieve = 0;      // retrieve position in queue[]
char *queue[100];      // this array forms the queue

void main(void)
{
  enter();    // enter some data in the queue and list the data
  puts("\n\nClient Sends Messages:");
  list(); 
  getchar();
}

//
// prompt for data entry and store in queue via q_store()
//
void enter(void)
{
  static char str[100], *ptr;

  do {
    printf("Enter message (ENTER only will exit) : ");
    gets(str);
    ptr = (char *) malloc(strlen(str));  // starting address of memory
    strcpy(ptr,str);
    if (*str) 
      q_store(ptr);  // store in queue if string has info
  } while (*str);    // until no entry
}

void list(void)  // list the contents of the queue
{
  int k;

  for (k = retrieve; k < store; k++)
  printf("Client Receives:%d) %s\n",k+1,queue[k]);
}

//
// store data items in the queue
//
void q_store(char *ptr)
{ 
  if (store == 100) {
    puts("\nList is full!"); 
    return;
  }
  queue[store] = ptr;
  store++;  // point to next available storage position in queue[]
}

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Don't use gets(): Explanations of... - Why gets() is bad / Buffer Overflows
Don't use void main(): What's the difference between... - main() / void main() / int main() / int main(void) / int main(int argc, char *argv[])
You should consider freeing your memory, too.

> int store = 0; // next storage position in queue[]
> int retrieve = 0; // retrieve position in queue[]
> char *queue[100]; // this array forms the queue
Put these things into a queue structure, so you can write things like
addToQueue( &myQueue, myString );

You will need multiple queues, so it makes sense to parameterise your queue functions to be able to add to any instance of a queue.

> ptr = (char *) malloc(strlen(str));
1. Don't cast malloc in C programs, see the FAQ
2. Don't forget to count the \0 as well when allocating space for strings.