Why are there U+200B characters in the subject? o_O
On Fri, Aug 17, 2012 at 07:57:49PM +0200, Dominik Danter wrote:
> Hi,
>
> I don't understand the following code:
>
> task "firewall", sub {
> iptables_clear;
> ...
> ...
> };
That is just a subroutine call. You don't always need the
parenthesis in Perl. In particular if Perl knows that the
bareword refers to a subroutine.
use strict;
use warnings;
# Perl needs to know about foo before we can call it without
# parenthesis. This predeclares it.
sub foo;
# Now we can call it without the parenthesis.
foo qw/bar baz bak/;
sub foo {
print "Called foo with these arguments: @_\n";
}
The sub { ... } part is just defining an anonymous subroutine and
passing a subroutine reference into the subroutine.
use strict;
use warnings;
sub foo;
# Call foo with anonymous subroutine as second argument.
foo "firewall", sub {
print 'Called anonymous subroutine via reference. ',
"Arguments: @_\n";
};
# You can also pass a reference to a named subroutine.
foo "firewall", \&named_sub;
sub foo {
my ($arg1, $sub) = @_;
print "Called foo with these arguments: @_\n";
# Calling the subroutine via reference.
$sub->($arg1);
}
sub named_sub {
print "Called named_sub with these arguments: @_\n";
}
See perldoc perlsub.
Regards,
--
Brandon McCaig <bamcc...@gmail.com> <bamcc...@castopulence.org>
Castopulence Software <https://www.castopulence.org/>
Blog <http://www.bamccaig.com/>
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q{Vg qbrfa'\''g nyjnlf fbhaq gung jnl.};
tr/A-Ma-mN-Zn-z/N-Zn-zA-Ma-m/;say'
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