B. TCP Socket Programming in Unix Using C Programming
Socket Programming Server Example Program
/*ECHO SERVER USING TCP IN C*/
#include<netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include<stdio.h>
#include <arpa/inet.h>
#include <string.h>
#include<fcntl.h>
main() {
int sd, cd;
char buf[100] = "";
struct sockaddr_in ser;
sd = socket(AF_INET, SOCK_STREAM, 0);
if (sd < 0)
printf("SOCKET NOT CREATED\n");
bzero(&ser, sizeof (struct sockaddr_in));
ser.sin_family = AF_INET;
ser.sin_port = htons(1012);
inet_aton("172.16.29.78", &ser.sin_addr);
int b = bind(sd, (struct sockaddr *) &ser, sizeof (ser));
printf("BIND VALUE:%d\n", b);
listen(sd, 5);
for (;;) {
cd = accept(sd, NULL, NULL);
int pid = fork();
if (pid == 0) {
printf("accept value %d\n", cd);
read(cd, buf, 100);
printf("MESSAGE FROM CLIENT:%s\n", buf);
write(cd, buf, strlen(buf));
close(cd);
}
}
close(sd);
}
Socket Programming Client Example Program
/*ECHO CLIENT USING TCP IN C*/
#include<netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include<stdio.h>
#include <arpa/inet.h>
#include <string.h>
#include<fcntl.h>
main() {
int sd, cd;
char buf[100] = "", buf1[100] = "";
struct sockaddr_in ser;
sd = socket(AF_INET, SOCK_STREAM, 0);
if (sd < 0)
printf("SOCKET NOT CREATED\n");
bzero(&ser, sizeof (struct sockaddr_in));
ser.sin_family = AF_INET;
ser.sin_port = htons(1012);
inet_aton("172.16.29.78", &ser.sin_addr);
int c = connect(sd, (struct sockaddr *) &ser, sizeof (ser));
printf("CONNET %d\n", c);
if (c < 0)
printf("CONNECTION FAILED\n");
for (;;) {
printf("ENTER THE MESSAGE");
scanf("%s", buf);
write(sd, buf, strlen(buf));
read(sd, buf1, 100);
printf("RECEIVED FROM SERVER%s\n", buf1);
}
close(sd);
close(cd);
}
Sample Output for Server:
cc tserver.c -o tser
./tser
BIND VALUE:0
accept value 4
MESSAGE FROM CLIENT:Hello
Sample Output for Client:
cc tclient.c -o tcli
./tcli
CONNET 0
ENTER THE MESSAGE
Hello