‘!$’ is the right answer.
For example: $vim test.pl
$chmod +x !$
$./!$
So what is happening above is
first vim test.pl opens a file.
then after you have written a perl script, you would like to make it executable. There is no need for you to specify the file name again. You can just use !$.
In the third command again to execute the file, there is no need to mention the file name again. You just use !$ again.
