warnings

warnings(3)	       Perl Programmers Reference Guide		  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
       The "warnings" pragma is a replacement for the command line flag "-w",
       but the pragma is limited to the enclosing block, while the flag is
       global.	See perllexwarn for more information.

       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 pack-
	   age.

	   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 pack-
	   age.

	   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 "Pragmatic Modules" in perlmodlib and perllexwarn.



perl v5.8.8			  2001-09-21			  warnings(3)