[FreshDoubleX]

pawn Код:

if (strcmp("/getip", cmdtext, true, 10) == 0)
    {
        new str[128], name[MAX_PLAYER_NAME], IP[16];
        GetPlayerName(playerid, name, sizeof(name));
        GetPlayerIp(playerid, IP, sizeof(IP));
        format(str, sizeof(str), "Name: %s  IP: %s", name, IP);
        ShowPlayerDialog(playerid, 1, DIALOG_STYLE_LIST, "Player's IP", str, "Exit", "");
        return 1;
    }

EDIT: It shows your IP, not some other guy. And it's better to use Zcmd.