C) basic Socket code (Server)

code from Computer_Networks_Larry_Peterson_5ed

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#define SERVER_PORT 47500
#define MAX_PENDING 5
#define MAX_LINE 256

int main() {
    struct sockaddr_in sin;
    char buf[MAX_LINE];
    int len;
    int s, new_s;

    /* build address data structure */
    bzero((char *)&sin, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_addr.s_addr = INADDR_ANY;
    sin.sin_port = htons(SERVER_PORT);

    /* setup passive open */
    if ((s = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
        perror("simplex-talk: socket");
        exit(1);
    }
    if ((bind(s, (struct sockaddr *)&sin, sizeof(sin))) < 0) {
        perror("simplex-talk: bind");
        exit(1);
    }
    listen(s, MAX_PENDING);

    /* wait for connection, then receive and print text */
    while(1) {
        if ((new_s = accept(s, (struct sockaddr *)&sin, &len)) < 0) {
            perror("simplex-talk: accept");
            exit(1);
        }
        while (len = recv(new_s, buf, sizeof(buf), 0))
            fputs(buf, stdout);
        close(new_s);
    }

}

bind()

https://docs.microsoft.com/en-us/windows/desktop/api/winsock/nf-winsock-bind

listen()

https://docs.microsoft.com/en-us/windows/desktop/api/winsock2/nf-winsock2-listen

accept()

https://docs.microsoft.com/en-us/windows/desktop/api/winsock2/nf-winsock2-accept

recv()

https://docs.microsoft.com/en-us/windows/desktop/api/winsock2/nf-winsock2-recv