Программирование сокетов

....
#define PORTNUM 13000
#define HOSTLEN 256
#define oops(msg) {perror(msg);exit(1);}
int main(int ac, char *av[]){
    struct sockaddr_in saddr;
    struct hostent *hp;
    char hostname[HOSTLEN];
    int sock_id, sock_fd;
    FILE *sock_fp;
    time_t thetime;
    if ((sock_id = socket(PF_INET, SOCK_STREAM, 0)) == -1)oops("socket");
    
    bzero ((void*)&saddr, sizeof(saddr));
    gethostname (hostname, HOSTLEN);
    hp = gethostbyname(hostname);
    printf("After gethostbyname!");
    .....

#include <stdio.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <strings.h>
#include <arpa/inet.h>
struct hostent *he;
struct in_addr a;
int
main (int argc, char **argv)
{
    if (argc != 2)
    {
        fprintf(stderr, "usage: %s hostname\n", argv[0]);
        return 1;
    }
    he = gethostbyname (argv[1]);
    if (he)
    {
        printf("name: %s\n", he->h_name);
        while (*he->h_aliases)
            printf("alias: %s\n", *he->h_aliases++);
        while (*he->h_addr_list)
        {
            bcopy(*he->h_addr_list++, (char *) &a, sizeof(a));
            printf("address: %s\n", inet_ntoa(a));
        }
    }
    else
        herror(argv[0]);
    return 0;
}

user@debian:~/project/c++/socket$ ./prog localhost
name: localhost
address: 127.0.0.1

user@debian:~/project/c++/socket$ ./prog debian   
name: debian.domain.name
alias: debian
address: 127.0.1.1

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