A simple logger for Perl

     Below is a simple logger for your custom perl applications.  The logger is created as a module and can be included in any script.  Code is explained within the program as comments

Module :


safeer@penguinpower:~$ cat DEV/Perl/MyLogger.pm

#!/usr/bin/perl -w
### Module Name is MyLogger
package MyLogger;
### Include Modules
use IO::File;
use DateTime;
use File::Basename;
use File::Spec;

### Constructor

sub new
{

my $class = shift;
### Object creation parameters
my(%params) = @_;
my $self = { };
### Identify the parent scripting using the class
(undef,$self{'caller'}) = caller;
### Whether to append current date to the log file name or not
### Off by default
$self->{'datedLogFile'} = $params{'datedLogFile'}  || 0;
### Whether to include scriptname in the log entries
### Off by default
$self->{'incScriptName'} = $params{'incScriptName'}  || 0;
### Whether to include scriptname - with full path - in the log entries
### Off by default
$self->{'incScriptWithPath'} = $params{'incScriptWithPath'}  || 0;
### Whether to include current date and time in log entries
## On by default
$self->{'incDateTime'} = $params{'incDateTime'} || 1;
### logFileBase - basename from which the logfile name should be constructed
if( defined $params{'logFileBase'} ) { 
$self->{'logFile'} = $params{'logFileBase'}; 
if( $self->{'datedLogFile'} == 1 ) { 
my $currentDate = DateTime->now->strftime('-%d-%m-%Y');
$self->{'logFile'} .= $currentDate;
}
### Append ".log" to the end of log file name
$self->{'logFile'} .= ".log";
}
else { print "No logfile defined!!" ; exit 1 ; }
### Open the file and store the file object pointer in the class
$self->{'log'} = IO::File->new;
$self->{'log'}->open("$self->{'logFile'}",">>");

bless $self,$class;
return $self;
}

### This function will do the actual logging
### It is preferred not to use this function directly
### Rather call the functions derived from this one
### Like debug,info,warn,crit
sub logme()
{
my $self = shift;
### Accept two parameters, log level ( DEBUG/INFO/WARN/CRIT )
### and log message ( can be multi line message ) 
my ($logLevel,$message) = @_ ;
### Breakup multiline messages and process line by line
@logentries = split("\n" , $message  );
foreach my $logentry ( @logentries ) {
my $logprefix = "";
### Include date and time
if( $self->{'incDateTime'} == 1 ) { 
  $timestamp = DateTime->now(time_zone=>"local")->strftime("[%d-%m-%Y %H:%M:%S]");
  $logprefix .= $timestamp ;
  }
### Add log level
$logprefix .=   "[" . $logLevel ."]" ;
### Include scriptname with path
if( $self->{'incScriptWithPath'} == 1 ) {
  my $scriptpath = File::Spec->rel2abs($self{'caller'}) ;
  $logprefix .= "[" . $scriptpath . "]"; 
  }
### Include scriptname wihtout path
elsif( $self->{'incScriptName'} == 1 ) { 
  my $scriptname = basename($self{'caller'}) ;
  $logprefix .= "[" . $scriptname . "]" ;
  }

$self->{'log'}->print( "$logprefix $logentry\n" );

}

}

### Following functions are defined for the convenience of user
### All of them calls logme() funcation  internally

### Used to register informative messages
sub info()
{
my $self = shift;
$self->logme("INFO",$_[0]);
}

### Used to register warning messages
sub warn()
{
my $self = shift;
$self->logme("WARN",$_[0]);
}

### Used to register critical messages
sub crit()
{
my $self = shift;
$self->logme("CRIT",$_[0]);
}

### Used to register debug messages
sub debug()
{
my $self = shift;
$self->logme("DEBUG",$_[0]);
}

### Destroyer
sub DESTROY
{
my $self = shift;
$self->{'log'}->close;
}


1;

Now use this module in a script


safeer@penguinpower:~/DEV/Perl$ cat loguse.pl

#!/usr/bin/perl
### Define custom library path for adding modules
use lib '/home/safeer/DEV/Perl/CustomModules';
### Include the cutom logger module
use MyLogger;
### Create an instance of custom logger
my $logger = MyLogger->new('logFileBase' => "/tmp/logPerl" , 'datedLogFile' => 1 , 'incScriptName' => 1 , 'incScriptWithPath' => 1 );
### Log all types of log messages
$logger->info("Information Message");
$logger->warn("Warning Message");
$logger->crit("Critical Message");
$logger->debug("Debug Message");

Execute the script

safeer@penguinpower:~/DEV/Perl$ ./loguse.pl

Look at the log file created

safeer@penguinpower:~$ cat /tmp/logPerl-17-07-2012.log
[17-07-2012 23:26:15][INFO][/home/safeer/DEV/Perl/loguse.pl] Information Message
[17-07-2012 23:26:15][WARN][/home/safeer/DEV/Perl/loguse.pl] Warning Message
[17-07-2012 23:26:15][CRIT][/home/safeer/DEV/Perl/loguse.pl] Critical Message
[17-07-2012 23:26:15][DEBUG][/home/safeer/DEV/Perl/loguse.pl] Debug Message