Untitled

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
void check(char strr[], int value)
{
if (value < 0)

{
perror(strr); 
exit(1);
}
}
int main()
{
int cid, con, csend, crec;
char sendbuff[500], recbuff[500], fromaddress[500], toaddress[500], mailbody[1000];
struct sockaddr_in caddr;
cid = socket(AF_INET, SOCK_STREAM, 0);
check("Socket creation", cid);
caddr.sin_family = AF_INET;
caddr.sin_port = htons(8080);
caddr.sin_addr.s_addr = inet_addr("127.0.0.1");
con = connect(cid, (struct sockaddr *)&caddr, sizeof(caddr));
check("CONNECTION", con);
printf("\n<--> CONNECTION ESTABLISHED <-->\n");
printf("Sending HI to server\n");
strcpy(sendbuff, "HI");
csend = send(cid, sendbuff, 500, 0);
check("SENDING", csend);
printf("Waiting for server response...\n");
crec = recv(cid, recbuff, 500, 0);
check("RECEIVE", crec);
printf("Message from server: %s\n", recbuff);
printf("Sending HELLO to server\n");
strcpy(sendbuff, "HELLO");
csend = send(cid, sendbuff, 500, 0);
check("SENDING", csend);
printf("Waiting for OK message\n");
crec = recv(cid, recbuff, 500, 0);
check("RECEIVE", crec);
if (strncmp(recbuff, "250", 3) != 0)
printf("OK NOT received\n");
else
printf("Message from server: %s\n", recbuff);
printf("Enter the FROM address: ");

scanf("%s", fromaddress);
strcpy(sendbuff, "MAIL FROM:");
strcat(sendbuff, fromaddress);
csend = send(cid, sendbuff, 500, 0);
check("SENDING", csend);
printf("Waiting OK from server\n");
crec = recv(cid, recbuff, 500, 0);
check("RECEIVE", crec);
if (strncmp(recbuff, "250", 3) != 0)
printf("OK NOT received\n");
else
printf("Message from server: %s\n", recbuff);
printf("Enter TO address: ");
scanf("%s", toaddress);
getchar();
strcpy(sendbuff, "MAIL TO:");
strcat(sendbuff, toaddress);
csend = send(cid, sendbuff, 500, 0);
check("SENDING", csend);
printf("Waiting OK from server\n");
crec = recv(cid, recbuff, 500, 0);
check("RECEIVE", crec);
if (strncmp(recbuff, "250", 3) != 0)
printf("OK NOT received\n");
else
printf("Message from server: %s\n", recbuff);
printf("Sending DATA to the server...\n");
strcpy(sendbuff, "DATA");
csend = send(cid, sendbuff, 500, 0);
check("SENDING", csend);
printf("Waiting OK from server\n");
crec = recv(cid, recbuff, 500, 0);
check("RECEIVE", crec);
if (strncmp(recbuff, "354", 3) != 0)
printf("OK NOT received\n");
else
printf("Message from server: %s\n", recbuff);
printf("Enter mail body (Type '$' on a new line to finish):\n");
while (1)
{
fgets(mailbody, sizeof(mailbody), stdin);
csend = send(cid, mailbody, 1000, 0);
check("SENDING", csend);
if (strncmp(mailbody, "$", 1) == 0)
break;
}
printf("Waiting OK from server\n");
crec = recv(cid, recbuff, 500, 0);
check("RECEIVE", crec);
if (strncmp(recbuff, "221", 3) != 0)
printf("OK NOT received\n");
else
printf("Message from server: %s\n", recbuff);
strcpy(sendbuff, "QUIT");
csend = send(cid, sendbuff, 1000, 0);
printf("Sending %s...\n", sendbuff);
strcpy(recbuff, "");
crec = recv(cid, recbuff, 500, 0);
if (strncmp(recbuff, "221 OK", 6) == 0)
{
printf("Exiting...\n");
}
printf("Connection Closed\n");
close(cid);
return 0;
}