sub getproxy {
	open(LOG,"$aclog") || die "Can't Open User Access Log: $!\n";
	@lines=<LOG>;
	close(LOG);

	$axs=@lines;
	$max2 = ($max - 2);
	if ($axs >= $max) {
	  open(LOG,">$aclog") || die "Can't Open User Access Log: $!\n";
	    print LOG "$host\n";
	    foreach $axs (0..$max2) {
	      print LOG $lines[$axs];
	    }
	} else {
	  open(LOG,">$aclog") || die "Can't Open User Access Log: $!\n";
	    print LOG "$host\n";
	    foreach $log (@lines) {
	      print LOG $log;
	    }
	}
	close(LOG);
}#getproxy END

$aclog はファイル名指定して
$max はﾛｸﾞ行数

http://たぶんこれで

参考：2000/03/08(水)02時17分52秒