[CalvinC]

Just loop through all players, and check if they're near the player that wrote, and then send the message.

pawn Код:

public OnPlayerText(playerid, text[])
{
    new Float:x, Float:y, Float:z; // Declares 3 floats
    GetPlayerPos(playerid, x, y, z); // Store the position of the player that wrote in the floats we created
    foreach(new i : Player) // Loop through all players, and define them as "i"
    {
        if(IsPlayerInRangeOfPoint(i, range, x, y, z)) SendPlayerMessageToPlayer(playerid, i, text);
            // If "i" is in range of the xyz (which is the position of the player that wrote) send him the message, change the range to the distance you want
    }
    return 1;
}

In /g, just use Send Player/Client MessageToAll.