man perlop "perlop - Perl operators and precedence" (at least in UNIX-like) answers this question: "Binary "=~" binds a scalar expression to a pattern match." – U. Windl Commented Apr 1, …

Here the sigil changes to $ to denote that you are accessing a scalar, however the trailing [0] tells perl that it is accessing a scalar element of the array in _ or in other words, @_. – Eric Strom

Dec 30, 2010 · perldoc perlvar is the first place to check for any special-named Perl variable info. Quoting: @_: Within a subroutine the array @_ contains the parameters passed to that …

Perl arrow operator has one other use: Class−>method invokes subroutine method in package Class. though it's completely different than your code sample. Only including it for …

Mar 13, 2015 · So, if the shell is handing you a bunch of file names, and you'd like to go through each one's data in turn, perl's <> operator gives you a nice way of doing that...it puts the next …

From Perl documentation:. OR List operators. On the right side of a list operator, it has very low precedence, such that it controls all comma-separated expressions found there.

Jan 25, 2015 · You can inspect the code actually used by Perl with the core module B::Deparse. This compiler backend module is activated with the option -MO=Deparse.

In Perl, the operator s/ is used to replace parts of a string. Now s/ will alter its parameter (the string) in place. I would however like to replace parts of a string befor printing it, as in

Feb 1, 2012 · The reason $_ is used so often is that some Perl operators assign to it by default, and others use its value as a default for their argument. It can lead to shorter code if you …

It's also worth noting that in some programming languages the first (0) argument is the command or script itself... not so in perl though, of course. – danieltalsky Commented Dec 12, 2008 at 5:46