什么是"提示"对套接字编程中的addrinfo名称意味着什么

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

int main(int argc, char *argv[]) {
    struct addrinfo hints, *res;
    int status;
    char ipstr[INET6_ADDRSTRLEN];

    if (argc != 3) {
        fprintf(stderr, "Usage: %s hostname port\n", argv[0]);
        exit(1);
    }

    memset(&hints, 0, sizeof hints);
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    if ((status = getaddrinfo(argv[1], argv[2], &hints, &res)) != 0) {
        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
        exit(1);
    }

    printf("IP addresses for %s:\n", argv[1]);

    struct addrinfo *p;
    for (p = res; p != NULL; p = p->ai_next) {
        void *addr;
        char *ipver;

        if (p->ai_family == AF_INET) {
            struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;
            addr = &(ipv4->sin_addr);
            ipver = "IPv4";
        } else {
            struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)p->ai_addr;
            addr = &(ipv6->sin6_addr);
            ipver = "IPv6";
        }

        inet_ntop(p->ai_family, addr, ipstr, sizeof ipstr);
        printf("%s: %s\n", ipver, ipstr);
    }

    freeaddrinfo(res);
    return 0;
}