Dear Monks,

Log::Log4perl is my preferred tool for logging and this time I want to access some values of its configuration from another application. I've read the documentation, but I didn't find any suitable method; so I started from parsing a configuration file, but very soon I realized that I also needed the variable expansion feature provided by Log4perl; after that I dived into the source and came back with the following class to accomplish the task:

package Log::Log4perl::Config::Standalone;

use Log::Log4perl::Config;
use Log::Log4perl::Config::PropertyConfigurator;
use Carp;

sub new {
  my ($class, $filename) = @_;

  confess "configuration '$filename' not found\n" unless -f $filename;

  my $cp = Log::Log4perl::Config::PropertyConfigurator->new;
  $cp->file( $filename );

  my $self = {
    data => $cp->parse()
  };

  return bless $self, $class;
}

sub value {
  my ($self, $path, $default) = @_;

  my @p = split /\./, $path;

  shift @p if $p[0] eq 'log4perl';

  my $found = 1;
  my $r = $self->{data};
  while (my $n = shift @p) {
    if (exists $r->{$n}) {
      $r = $r->{$n};
    }
    else {
      $found = 0;
    }
  }

  return $found ? $r->{value} : $default;
}

1;

__END__

[download]
Given the following configuration file: 
# filename: l4p.conf
global_var = /var/log/some/file.log

log4perl.rootLogger = DEBUG, LOGFILE
log4perl.appender.LOGFILE = Log::Log4perl::Appender::File
log4perl.appender.LOGFILE.filename = ${global_var}
log4perl.appender.LOGFILE.mode = append
log4perl.appender.LOGFILE.layout = PatternLayout
log4perl.appender.LOGFILE.layout.ConversionPattern = %d{ISO8601} [%P] 
+%C %p %m%n

[download]
this code retrieves a value: 
use Log::Log4perl::Config::Standalone;

my $c = Log::Log4perl::Config::Standalone->new('./l4p.conf');
print $c->value('log4perl.appender.LOGFILE.filename'), "\n";

[download]
What do you think about it? How would you solve the same problem?

Thanks, Valerio

In reply to Accessing Log::Log4perl Configuration Values by valdez

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