What is the meaning of the vertical bar when used with m?

[Akino877]

Hello,

I am trying to understand the following line of Perl code :

($a_month, $a_day, $a_year) = $a =~ m|(\d\d?)/(\d\d?)/(\d{4})|;

I understand that the end result is that $a_month will get 1 or more digits; $a_day will get one or more digits; and $a_year will get 4 digits. But I would like to understand the meaning of 'm' and the vertical bars in this context.

Could someone please help me?

Thank you - Akino

[RonB]

It's documented in perldoc perlre