unit unix_iph;

interface

type
	ip_address = array[0..3] of string;
	pip_address = ^ip_address;

procedure normalize_ip(ip: pip_address);
procedure set_ip_data(address: ip_address; netmask: ip_address; gateway: ip_address);
procedure get_ip_data(out address: ip_address; out netmask: ip_address; out gateway: ip_address);

implementation

uses SysUtils, StrUtils;

procedure normalize_ip(ip: pip_address);
var i: integer;
begin
	if (not trystrtoint(ip^[0], i)) then ip^[0] := '0';
	if (not trystrtoint(ip^[1], i)) then ip^[1] := '0';
	if (not trystrtoint(ip^[2], i)) then ip^[2] := '0';
	if (not trystrtoint(ip^[3], i)) then ip^[3] := '0';
end;

function set_ip(ip: ip_address): string;
begin
	result := ip[0] + '.' + ip[1] + '.' + ip[2] + '.' + ip[3];
end;

procedure set_ip_data(address: ip_address; netmask: ip_address; gateway: ip_address);
var
	tf: textfile;
begin
	assignfile(tf, '/etc/network/interfaces');
	rewrite(tf);
	writeln(tf, 'iface eth0 inet static');
	write(tf, '	address ');
	writeln(tf, set_ip(address));
	write(tf, '	netmask ');
	writeln(tf, set_ip(netmask));
	write(tf, '	gateway ');
	writeln(tf, set_ip(gateway));
	closefile(tf);
	SysUtils.ExecuteProcess('/etc/init.d/networking', 'restart', []);
end;

function get_ip(s: string): ip_address;
var
   i, j: integer;
begin
	result[0] := '';
	result[1] := '';
	result[2] := '';
	result[3] := '';
	j := 0;
	for i := 1 to length(s) do
	begin
		if (s[i] = '.') then
		begin
			j := j + 1;
			if (j > 3) then
			begin
				break;
			end;
		end
		else
		begin
			result[j] := result[j] + s[i];
		end;
	end;
end;

procedure get_ip_data(out address: ip_address; out netmask: ip_address; out gateway: ip_address);
var
	list: array[0..3] of string;
	tf: textfile;
	line: string;
begin
	if fileexists('/etc/network/interfaces') then
	begin
		assignfile(tf, '/etc/network/interfaces');
		reset(tf);
		while not eof(tf) do
		begin
			readln(tf, line);
			line := trim(line);
			list := get_ip(rightstr(line, length(line) - 8));
			case leftstr(line, 8) of
				'address ':
				begin
					address := list;
				end;
				'netmask ':
				begin
					netmask := list;
				end;
				'gateway ':
				begin
					gateway := list;
				end;
			end;
		end;
		closefile(tf);
	end;
end;

end.