[Scenario]

There's no reason to check if a player is logged in on each command as you can do it with one of ZCMD's callbacks. Furthermore, you're dealing with a single string- there's no reason to use sscanf here.

You can't do it in two lines, but it's close enough! And remember, the amount of lines in a script really don't mean a damn thing.

pawn Код:

public OnPlayerCommandReceived(playerid, cmdtext[])
{
    if(!IsPlayerLoggedIn(playerid))
    {
        SendClientMessage(playerid, COLOR_GREY, "You need to login first before using any command.");
        return 0;
    }
    return 1;
}

CMD:me(playerid, params[])
{
    if(AntiAdv(playerid, params[]))
        return 1;
    if(strlen(params) < 3) // if the "action" in the /me command was less than 3 characters in length, the command won't process
        return 1;
    
    new
        string[144];
    
    format(string, sizeof(string), "* %s %s", RPN(playerid), params);
    SendNearbyMessage(playerid, 15, string, COLOR_PURPLE, COLOR_PURPLE, COLOR_PURPLE, COLOR_PURPLE, COLOR_PURPLE);
    return 1;
}

CMD:do(playerid, params[])
{
    if(AntiAdv(playerid, params[]))
        return 1;
    if(strlen(params) < 3) // if the "description" in the /do command was less than 3 characters in length, the command won't process
        return 1;
    
    new
        string[144];
    
    format(string, sizeof(string), "* %s (( %s ))", params, RPN(playerid));
    SendNearbyMessage(playerid, 15, string, COLOR_PURPLE, COLOR_PURPLE, COLOR_PURPLE, COLOR_PURPLE, COLOR_PURPLE);
    return 1;
}

Try searching BEFORE posting next time, please.