Implementing a C program for listing interfaces on device. This is much like the ifconfig command on Linux

myifconfig.c

#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netdb.h>
#include <ifaddrs.h>
#include <net/if.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>


int main() {

    //A strcuture that has the linked list of all internet addresses on the machine
    struct ifaddrs *addresses;

    //getifaddrs is use to allocate memory for storing the linked list
    if(getifaddrs(&addresses) == -1) {
        printf("getifaddrs failed\n");
        return 1;
    }


    // get each address and loop through to print them
    struct ifaddrs *address = addresses;


    while(address) {

        int family = address->ifa_addr->sa_family;
        if(family == AF_INET || family == AF_INET6) {

            if(family == AF_INET) {

                char ap6[100] = {0};
                char np6[100] = {0};

                struct ifaddrs *tmp = addresses;
                while(tmp) {
                    if(tmp->ifa_addr->sa_family == AF_INET6) {
                        if(strcmp(address->ifa_name, tmp->ifa_name) == 0) {
                            const int fsize = sizeof(struct sockaddr_in6);
                            getnameinfo(tmp->ifa_addr, fsize, ap6, sizeof(ap6),
                            0, 0, NI_NUMERICHOST);
                            getnameinfo(tmp->ifa_netmask, fsize, np6, sizeof(np6),
                            0, 0, NI_NUMERICHOST);
                            break;
                        }
                    }
                    tmp = tmp->ifa_next;
                }


                const int family_size = sizeof(struct sockaddr_in6);
                char ap[100];

                getnameinfo(address->ifa_addr, family_size,
                ap, sizeof(ap), 0, 0, NI_NUMERICHOST);

                char np[100];
                getnameinfo(address->ifa_netmask, family_size,
                np, sizeof(np), 0, 0, NI_NUMERICHOST);
                unsigned int flags = address->ifa_flags;
                char *name = address->ifa_name;

                const char *yellow = "\033[1;33m",
                            *green = "\033[0;32m",
                            *reset = "\e[0m";

                struct ifreq ifr;
                strcpy(ifr.ifr_name, address->ifa_name);
                int sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
                ioctl(sock, SIOCGIFFLAGS, &ifr);

                printf("%s:   flags=<", name);
                if(ifr.ifr_flags & IFF_UP)
                    printf("%sUP%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_BROADCAST)
                    printf("%sBROADCAST%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_DEBUG)
                    printf("%sDEBUG%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_LOOPBACK)
                    printf("%sLOOPBACK%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_POINTOPOINT)
                    printf("%sPOINTTOPOINT%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_NOTRAILERS)
                    printf("%sNOTRAILERS%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_RUNNING)
                    printf("%sRUNNING%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_NOARP)
                    printf("%sNOARP%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_PROMISC)
                    printf("%sPROMISC%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_ALLMULTI)
                    printf("%sALLMULTI%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_MASTER)
                    printf("%sNO-MASTER%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_SLAVE)
                    printf("%sSLAVE%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_MULTICAST)
                    printf("%sMULTICAST%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_PORTSEL)
                    printf("%sPORTSEL%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_AUTOMEDIA)
                    printf("%sAUTOMEDIA%s,", yellow, reset);
                if(ifr.ifr_flags & IFF_DYNAMIC)
                    printf("%sDYNAMIC%s,", yellow, reset);

                printf("\b> mtu %d\n", ifr.ifr_mtu);
                if(ifr.ifr_flags & IFF_BROADCAST) {
                    char broad[100];
                    getnameinfo(address->ifa_broadaddr, family_size, broad,
                    sizeof(broad), 0, 0, NI_NUMERICHOST);
                    printf("\tinet %s%s%s netmask %s%s%s broadcast %s%s%s\n"
                    , green, ap, reset, green, np, reset, green, broad, reset);
                } else if(ifr.ifr_flags & IFF_POINTOPOINT) {
                    char ptp[100];
                    getnameinfo(address->ifa_dstaddr, family_size, ptp,
                    sizeof(ptp), 0, 0, NI_NUMERICHOST);
                    printf("\tinet %s%s%s netmask %s%s%s point-to-point %s%s%s\n"
                    , green, ap, reset, green, np, reset, green, ptp, reset);
                } else
                    printf("\tinet %s%s%s netmask %s%s%s\n"
                    , green, ap, reset, green, np, reset);
                if(strlen(ap6) > 1 || strlen(np6) > 1)
                    printf("\tinet6 %s%s%s netmask %s%s%s\n"
                    , green, ap6, reset, green, np6, reset);

            }

        }

        address = address->ifa_next;
    }
    freeifaddrs(addresses);

    return 0;
}