'$ path =〜s | / $ ||'是什么 在perl中做？

Question

I find this piece of code in an opensource project. The path will be a UNIX path and passed as a parameter. I was wondering what the following code actually do for me :

$path =~ s|/$||;

Thanks!

* *Update:

Thanks for telling me the answer, however, I would like to know how the code rewrite in common regular expression matching will be?

I can't figure out the piece enclosed with vertical bar.

What is the second last vertical bar means? Thank you!

Answer 1

This code will remove a slash / found at the end of the string in $path . So, if you have

$path = "foo/bar/";

You will get

$path = "foo/bar";

This is a variation on the s/// operator, where the delimiter has been changed from / to | , eg s||| . With the s/// operator, you can exchange the slash / to almost any other character. For example

s!foo!bar!
s{foo}{bar}
s#foo#bar#
s?foo?bar?

The reason for changing delimiter is usually that such a character appears in the regex, which it does here. If your regex had not changed delimiter, it would look like this:

s/\/$//

Which is not as readable.