BEGIN {...}; in Perl

Question

I have a perl-script:

#!/usr/bin/perl 

BEGIN {
        print "That's BEGIN message\n";
BEGIN { print "That's BEGIN-2 message\n"; };
END { print "That's END message\n"; };
BEGIN { print "That's BEGIN-3 message\n"; };
};

It works so:

That's BEGIN-2 message
That's BEGIN-3 message
That's BEGIN message
That's END message

But why? It must prints in line 1 That's BEGIN message or no?

I'm curious as how you came to think of writing this code? – simlev Sep 13 '18 at 14:45 — simlev, Sep 13 '18 at 14:45

score 10 · Accepted Answer · answered Sep 08 '18 at 21:41

10

The first BEGIN isn't run until it is completely defined (see documentation). That doesn't happen until the end of the last }.

The others get run as they're completely defined — earlier.

answered Sep 08 '18 at 21:41

Thomas Dickey

76,765

BEGIN {...}; in Perl

1 Answers1