Re: [log4perl-devel] modifying caller_depth

[Mike S. <m...@pe...>]

Viner, David wrote on 7/9/2004, 4:03 PM:

 > from reading the perldoc page, I noticed that I can modify the value of
 > $Log::Log4perl::caller_depth if I use the logger from a wrapper class.
 >
 > how can I discover at runtime by how much to increment this value?
 >
 > that is, my wrapper class might be used in a variety of different
 > "depths".
 > How can I figure out what to add to caller_depth to make it work
 > properly?

This reminds me of a post that we had a while ago here, regarding 
finding out how to indent log messages, based on the caller level, check 
it out:

Pete Siemsen wrote on 12/29/2003, 4:37 PM:

  > It seems like "Custom Cspecs" in PatternLayouts is the way to do
  > this in log4perl.

If you don't mind the expense of a bunch of caller() calls per logged
message, here's a solution:

use Log::Log4perl qw(get_logger);

####################
sub level {
####################
      my $i = 0;
      $i++ while caller($i);
      return $i-6;
}

my $conf = q(
log4perl.PatternLayout.cspec.Y = sub { "  " x level() }
log4perl.category                  = WARN, Logfile
log4perl.appender.Logfile          = Log::Log4perl::Appender::Screen
log4perl.appender.Logfile.layout   = PatternLayout
log4perl.appender.Logfile.layout.ConversionPattern = %Y%m%n
);

Log::Log4perl::init(\$conf);

my $logger = get_logger("");
$logger->error("first");
bar();
$logger->error("first");

sub bar { $logger->error("second"); foo(); }
sub foo { $logger->error("third"); }

__END__

The $i-6 expression might need to be adapted if caller_level is set to
anything but 0. Here's the output:

first
    second
      third
first

--
-- Mike
Mike Schilli
m...@pe...