


warnings(3p)     Perl Programmers Reference Guide    warnings(3p)


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.



2001-05-24                 perl v5.6.1                          1





warnings(3p)     Perl Programmers Reference Guide    warnings(3p)


           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. Oth-
           erwise 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.




2001-05-24                 perl v5.6.1                          2


