Compilation error in writing a client side program - c

Question

I am new to socket programming.I looked at a program in the Tutorialspoint.I made a little changes to the program but while compiling I am encountering errors.I am attaching an image telling about the errors..
In addition, I don't understand what is sin_family and sin_port.Shall I replace them with serv_addr_family and serv_addr_port respectively?
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <netdb.h>
#define portno 5432
int main(int argc, char *argv[])
{
int sockfd,n;
const struct sockaddr_in serv_addr;
const struct hostent *server;
char buffer[256];
if (argc < 3) {
fprintf(stderr,"usage %s hostname port\n", argv[0]);
return;
}
server = gethostbyname(argv[1]);
if (server == NULL) {
fprintf(stderr,"ERROR, no such host\n");
return;
}
/* Create a socket point */
bzero((char *)&serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy(*server->h_addr,
(char *)&serv_addr.sin_addr,
server->h_length);
serv_addr.sin_port = htons(portno);
sockfd = socket(PF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
perror("ERROR opening socket");
return;
}
/* Now connect to the server */
if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
{
perror("ERROR connecting");
return;
}
/* Now ask for a message from the user, this message
* will be read by server
*/
printf("Please enter the message: ");
bzero(buffer,256);
fgets(buffer,255,stdin);
/* Send message to the server */
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
{
perror("ERROR writing to socket");
return;
}
/* Now read server response */
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
{
perror("ERROR reading from socket");
return;
}
printf("%s\n",buffer);
return 0;
}

Answer 1

you have to remove const before the stuct.
it's used to configure your socket.(port, ip, ...)
int sockfd,n;
const struct sockaddr_in serv_addr;
const struct hostent *server;
to
int sockfd,n;
struct sockaddr_in serv_addr;
struct hostent *server;

Answer 2

There are a few things to correct here:
Firstly,
const struct sockaddr_in serv_addr;
You won't be able to modify serv_addr as it is read-only.
So you may need to remove the const keyword.
On rectifying the above step. You will still run into undefined-behavior in the following statement.
bcopy(*server->h_addr, (char *)&serv_addr.sin_addr, server->h_length);
Change to to below:
bcopy(server->h_addr, (char *)&serv_addr.sin_addr, server->h_length);
Notice the removal of * in the first argument.
The deference is incorrect.
As per comments, I too recommend usage of memcpy like functions.
As a part of good coding practice. Always return with the proper return-type.
Leads to -Wreturn-type as your main expects an int returned .
Example Change:
if (server == NULL) {
fprintf(stderr,"ERROR, no such host\n");
return;
}
to return -1 maybe.