Les sockets en C sont des mécanismes de programmation utilisés pour établir des communications réseau entre des applications. Ils permettent aux programmes de s'échanger des données en utilisant les protocoles TCP/IP (Transmission Control Protocol/Internet Protocol) pour la communication sur Internet. Un programme qui utilise des sockets peut agir en tant que client ou serveur. En tant que client, il se connecte à un serveur distant pour envoyer ou recevoir des données. En tant que serveur, il écoute les connexions entrantes des clients et peut leur envoyer ou recevoir des données.

1. Tp Socket C
Tcp
Serveur :
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define closesocket(s) close(s)
int main(){
typedef int SOCKET;
typedef struct sockaddr_in SOCKADDR_IN;
typedef struct sockaddr SOCKADDR;
SOCKET sock;
sock=socket(AF_INET,SOCK_STREAM,0);
printf("n creation de sock serv");
SOCKADDR_IN addrS;
addrS.sin_family=AF_INET;
addrS.sin_port=htons(1050);
Réaliser par: Anas AOUINA

2. addrS.sin_addr.s_addr=htonl(INADDR_ANY);
printf(" n remplissage de sock_in");
bind(sock,(SOCKADDR*)&addrS,sizeof(addrS));
printf("n association d'info");
listen(sock,0);
printf("n mettre en etat d'ecoute");
SOCKET so_client;
printf("n declaration de sock client");
SOCKADDR_IN client;
int taille=sizeof(client);
so_client=accept(sock,(SOCKADDR*)&client,&taille);
printf("n acceptation");
char buffer[100];
int n;
strcpy(buffer,"Bonjour n");
send(so_client,buffer,sizeof(buffer),0);
printf("n send");
recv(so_client,buffer,sizeof(buffer),0);
n=strlen(buffer);
buffer[n]='0';
printf("n le mssg recu %s n",buffer);
closesocket(so_client);

3. closesocket(sock);
}
Client :
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define closesocket(s) close(s)
int main(){
typedef int SOCKET;
typedef struct sockaddr_in SOCKADDR_IN;
typedef struct sockaddr SOCKADDR;
SOCKET sock_cl;
sock_cl=socket(AF_INET,SOCK_STREAM,0);
printf("n creation de sock serv");
SOCKADDR_IN addrC;
addrC.sin_family=AF_INET;
addrC.sin_port=htons(1050);
addrC.sin_addr.s_addr=htonl(INADDR_ANY);
printf("n remplissage de sock_in");

4. connect(sock_cl,(SOCKADDR*)&addrC,sizeof(addrC));
printf("n bien connecter");
char buffer[100];
int n;
recv(sock_cl,buffer,sizeof(buffer),0);
n=strlen(buffer);
buffer[n]='0';
printf("n le mssg recu %s n",buffer);
strcpy(buffer," n hello n");
send(sock_cl,buffer,sizeof(buffer),0);
printf("send");
closesocket(sock_cl);
}
Udp
Serveur :
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define closesocket(s) close(s)
int main(){

5. typedef int SOCKET;
typedef struct sockaddr_in SOCKADDR_IN;
typedef struct sockaddr SOCKADDR;
/*la declaration de socket serveur */
SOCKET sock_serv;
/*la creation de socket serveur */
sock_serv = socket(AF_INET, SOCK_DGRAM, 0);
/*declaration et initialisation de la structure SOCKADDR_IN */
SOCKADDR_IN addrS;
addrS.sin_family = AF_INET;
addrS.sin_port = htons(1050);
addrS.sin_addr.s_addr = htonl(INADDR_ANY);
/* Bind socket */
if (bind(sock_serv, (SOCKADDR *)&addrS, sizeof(addrS)) ==
SOCKET_ERROR) {
printf("Error binding socketn");
return 1;
}
/* Preparer buffer et socket */
char buffer[100];
int recv_len;
SOCKADDR_IN client_addr;
int client_addr_len = sizeof(client_addr);
memset(buffer, 0, sizeof(buffer));
/* attend le message de client */
if ((recv_len = recvfrom(sock_serv, buffer, sizeof(buffer), 0,
(SOCKADDR *)&client_addr, (socklen_t *)&client_addr_len)) ==
SOCKET_ERROR) {

6. printf("Error receiving messagen");
return 1;
}
/* afficher le message recu message */
printf("Received message from client: %sn", buffer);
/* envoie de reponse au client */
char response[100] = "Hello ";
sendto(sock_serv, response, strlen(response), 0, (SOCKADDR
*)&client_addr, sizeof(client_addr));
/* fermer socket */
closesocket(sock_serv);
return 0;
}Client :
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define closesocket(s) close(s)
int main(){
typedef int SOCKET;
typedef struct sockaddr_in SOCKADDR_IN;
typedef struct sockaddr SOCKADDR;
/*la declaration de socket serveur */
SOCKET sock_cl;

7. /*la creation de socket serveur */
sock_cl=socket(AF_INET,SOCK_DGRAM,0);
/*declaration et initialisation de la structure SOCKADDR_IN */
SOCKADDR_IN addrC;
addrC.sin_family=AF_INET;
addrC.sin_port=htons(1050);
addrC.sin_addr.s_addr=INADDR_ANY;
/envoie du mssg au serveur/
char buffer[100];
strcpy(buffer," n hello ");
printf("le mssg envoi est :%s n",buffer);
sendto(sock_cl,buffer,sizeof(buffer),0,(SOCKADDR*)&addrC,sizeof(addrC)
);
/fermeture de socket/
close(sock_cl);
}