perl if else循环

[oracle@jhoa 7]$ cat 5.pl 
if ( $#ARGV < 0 ){
        print "请输入一个日期参数
";
        exit(-1);
    }
  $var = $ARGV[0];
if ($var =~/xy/) ##匹配xy字符
{print "ok
"} 
else
{print "no
"}



[oracle@jhoa 7]$ perl 5.pl  xy
ok
[oracle@jhoa 7]$ perl 5.pl  xyzz
ok
[oracle@jhoa 7]$ perl 5.pl  yyy
no