warnings(3)

NAME

warnings - Perl pragma to control optional warnings

SYNOPSIS

use warnings;
no warnings;
use warnings "all";
no warnings "all";
use warnings::register;
if (warnings::enabled()) {
    warnings::warn("some warning");
}
if (warnings::enabled("void")) {
    warnings::warn("void", "some warning");
}
if (warnings::enabled($object)) {
    warnings::warn($object, "some warning");
}
warnings::warnif("some warning");
warnings::warnif("void", "some warning");
warnings::warnif($object, "some warning");

DESCRIPTION

If no import list is supplied, all possible warnings are
either enabled or disabled.

A number of functions are provided to assist module
authors.

use warnings::register

Creates a new warnings category with the same name as
the package where the call to the pragma is used.

warnings::enabled()

Use the warnings category with the same name as the
current package.

Return TRUE if that warnings category is enabled in
the calling module. Otherwise returns FALSE.

warnings::enabled($category)

Return TRUE if the warnings category, $category, is
enabled in the calling module. Otherwise returns
FALSE.

warnings::enabled($object)

Use the name of the class for the object reference,
$object, as the warnings category.

Return TRUE if that warnings category is enabled in
the first scope where the object is used. Otherwise
returns FALSE.

warnings::warn($message)

Print $message to STDERR.

Use the warnings category with the same name as the
current package.

If that warnings category has been set to "FATAL" in
the calling module then die. Otherwise return.

warnings::warn($category, $message)

Print $message to STDERR.

If the warnings category, $category, has been set to
"FATAL" in the calling module then die. Otherwise
return.

warnings::warn($object, $message)

Print $message to STDERR.

Use the name of the class for the object reference,
$object, as the warnings category.

If that warnings category has been set to "FATAL" in
the scope where $object is first used then die. Other
wise return.

warnings::warnif($message)

Equivalent to:

if (warnings::enabled())

{ warnings::warn($message) }

warnings::warnif($category, $message)

Equivalent to:

if (warnings::enabled($category))

{ warnings::warn($category, $message) }

warnings::warnif($object, $message)

Equivalent to:

if (warnings::enabled($object))

{ warnings::warn($object, $message) }

See "Pragmatic Modules" in perlmodlib and perllexwarn.

perl v5.8.0 2002-06-01 warnings(3)