MDC(3) User Contributed Perl Documentation MDC(3)
NAME
Log::Log4perl::MDC - Mapped Diagnostic Context
DESCRIPTION
Log::Log4perl allows loggers to maintain global thread-specific data,
called the Nested Diagnostic Context (NDC) and Mapped Diagnostic
Context (MDC).
The MDC is a simple thread-specific hash table, in which the
application can stuff values under certain keys and retrieve them later
via the "%X{key}" placeholder in
"Log::Log4perl::Layout::PatternLayout"s.
Log::Log4perl::MDC->put($key, $value);
Store a value $value under key $key in the map.
my $value = Log::Log4perl::MDC->get($key);
Retrieve the content of the map under the specified key. Typically
done by %X{key} in "Log::Log4perl::Layout::PatternLayout". If no
value exists to the given key, "undef" is returned.
my $text = Log::Log4perl::MDC->remove();
Delete all entries from the map.
Log::Log4perl::MDC->get_context();
Returns a reference to the hash table.
Please note that all of the methods above are class methods, there's no
instances of this class. Since the thread model in perl 5.8.0 is "no
shared data unless explicitly requested" the data structures used are
just global (and therefore thread-specific).
LICENSE
Copyright 2002-2013 by Mike Schilli <m@perlmeister.com> and Kevin Goess
<cpan@goess.org>.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
AUTHOR
Please contribute patches to the project on Github:
http://github.com/mschilli/log4perl
Send bug reports or requests for enhancements to the authors via our
MAILING LIST (questions, bug reports, suggestions/patches):
log4perl-devel@lists.sourceforge.net
Authors (please contact them via the list above, not directly): Mike
Schilli <m@perlmeister.com>, Kevin Goess <cpan@goess.org>
Contributors (in alphabetical order): Ateeq Altaf, Cory Bennett, Jens
Berthold, Jeremy Bopp, Hutton Davidson, Chris R. Donnelly, Matisse
Enzer, Hugh Esco, Anthony Foiani, James FitzGibbon, Carl Franks, Dennis
Gregorovic, Andy Grundman, Paul Harrington, Alexander Hartmaier David
Hull, Robert Jacobson, Jason Kohles, Jeff Macdonald, Markus Peter,
Brett Rann, Peter Rabbitson, Erik Selberg, Aaron Straup Cope, Lars
Thegler, David Viner, Mac Yang.
perl v5.30.0 2017-02-21 MDC(3)
log-log4perl 1.490.0 - Generated Mon Jul 20 10:45:56 CDT 2020