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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");
      }

      warnif("some warning");
      warnif("void", "some warning");
      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. Otherwise 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 the Pragmatic Modules entry in the perlmodlib manpage and the
  perllexwarn manpage.

Index for Section 3

Alphabetical listing for W

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