$|++;
package Foo;
{

    use strict;
    use warnings;
    use warnings::register;

    sub t {
        warnings::warnif "Bang! '@_'";
        print ": @_\n";
    }
}

package main;
{

    no warnings;
    Foo::t('no warnings');
}
{
    use warnings;
    Foo::t('use warnings');
}
{
    use warnings;
    no warnings 'Foo';
    Foo::t('no warnings "Foo"');
}
{
    no warnings;
    use warnings 'Foo';
    Foo::t('use warnings "Foo"');
}
__END__
: no warnings
Bang! 'use warnings' at C:\Temp\warnings_register.pl line 23
: use warnings
: no warnings "Foo"
Bang! 'use warnings "Foo"' at C:\Temp\warnings_register.pl line 33
: use warnings "Foo"
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.