[Nero_3D]

Basic repeating callback

pawn Код:

forward RepetitiveHeal(interval, Float: heal, tic);
public RepetitiveHeal(interval, Float: heal, tic) {
    if(0 < tic) {
        new
            Float: health
        ;
        for(new i; i != MAX_PLAYERS; ++i) { // use foreach if you have it
            if(GetPlayerHealth(i, health)) {
                SetPlayerHealth(i, health + heal);
            }
        }
        SetTimerEx("RepetitiveHeal", interval, false, "ifi", interval, heal, tic - 1);
    }
}

Call it like any other function, in your case

pawn Код:

cmd_virus(playerid, params[]) {
    #pragma unused params
    // all 1000 ms, -5.0 health each time, 15 times
    RepetitiveHeal(1000, -5.0, 15);
    return true;
}