[ThePhenix]

Not tested:

PHP Code:

public OnPlayerCommandText(playerid, cmdtext[])
{
new MSG[250];
new Name[MAX_PLAYER_NAME];
GetPlayerName(playerid,Name,sizeof(Name));
    if (strcmp("/greet", cmdtext, true, 10) == 0)
    {
        if(PlayerInfo[playerid][pCop] == 1){
            if(PlayerToPlayer(playerid,5, 10.0)){
                format(MSG,sizeof(MSG),"Hello, I'm %s [Police Officer] with the Los Santos Police Department. Do you know why I stopped you today?", Name);
                SendClientMessage(playerid, COLOR_WHITE, MSG);{
        return 1;
    }
    return 0;
}
stock PlayerToPlayer(playerid, targetid, Float:distance)
{
    new Float:x, Float:y, Float:z;
    GetPlayerPos(playerid,x,y,z);
    if(IsPlayerInRangeOfPoint(targetid,distance,x,y,z))
    {
        return true;
    }
    return false;
}