Compile time and Run time in perl

问题

I am reading this document to understand the life cycle of a Perl program.

I am unable to figure out when RUN time and when COMPILE time events occur while running a perl script on a command line like this:

perl my_script.pl

回答1:

perl script.pl will compile script.pl then execute script.pl. Similarly, require Module; will compile Module.pm then execute Module.pm.

If the compiler encounters a BEGIN block, it will execute the block as soon as the block is compiled. Keep in mind that use is a BEGIN block consisting of a require and possibly a import.

For example,

# script.pl
use Foo;
my $foo = Foo->new();
$foo->do();

Does:

1. Compile script.pl
   1. Compile use Foo;
   2. Execute require Foo;
      1. Compile Foo.pm
         1. ...
      2. Execute Foo.pm
         1. ...
   3. Execute import Foo;
   4. Compile my $foo = Foo->new();
   5. Compile $foo->do();
2. Execute script.pl
   1. Execute my $foo = Foo->new();
   2. Execute $foo->do();

来源：https://stackoverflow.com/questions/14766878/compile-time-and-run-time-in-perl