program FLIST (input, tty);   { list a file with line numbers }
 
var
    filename: array[1..20] of char;
    lineno: integer;
    i: integer;
    c: char;
 
begin
write (tty, 'Enter name of file to be listed: '); break; readln(tty);
filename := '                    ';
i := 1
while not eoln(tty) do
    begin  read(tty, filename[i]); i := i + 1  end;
reset ( input, filename );
 
lineno := 0 ;
while not eof(input) do
    begin
    lineno := lineno + 1 ;
    write (tty, lineno:4, ' ');
    i := 5;   { current column }
    while not eoln(input) do
	begin
	read (input, c);
	i := i + 1 ;
	if i <= 79  then   write (tty, c)
	end;
    readln (input);
    writeln (tty)
    end
end.