Untitled

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<netdb.h>
#include<unistd.h>

void check(char str[],int value)
{
 if(value<0)
 {
 perror(str);
 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(8083);
    caddr.sin_addr.s_addr=inet_addr("127.0.0.1");
    con=connect(cid,(struct sockaddr*)&caddr,sizeof(caddr));
    check("CONNECTION",con);
    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("RECIEVE",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("RECIEVE",crec);
    if(strncmp(recbuff,"250",3)!=0)
    printf("OK not recieved\n");
    else
    printf("message from server:%s\n",recbuff);
    
    printf("Enter 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 sever\n");
    crec=recv(cid,recbuff,500,0);
    check("RECIEVE",crec);
    if(strncmp(recbuff,"250",3)!=0)
    printf("OK not recieved\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 for OK message...\n");
    crec=recv(cid,recbuff,500,0);
    check("RECIEVE",crec);
    if(strncmp(recbuff,"250",3)!=0)
    printf("OK not recieved\n");
    else
    printf("message from server:%s\n",recbuff);
    
    printf("sending DATA to server...\n");
    strcpy(sendbuff,"DATA");
    csend=send(cid,sendbuff,500,0);
    check("SENDING",csend);
    printf("waiting for OK message...\n");
    crec=recv(cid,recbuff,500,0);
    check("RECIEVE",crec);
    if(strncmp(recbuff,"354",3)!=0)
    printf("OK not recieved\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");
     check("RECIEVE",crec);
    if(strncmp(recbuff,"250",3)!=0)
    printf("OK not recieved\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;
}