package secondPakage;
use strict;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
@ISA = qw(Exporter);
@EXPORT = qw( &WriteLOG );
@EXPORT_OK = qw();
%EXPORT_TAGS = ( );
our $LOGFile= "";

sub WriteLOG {                                                                                                            
    my ($msg) = @_;
    my $ltime=localtime;
    $ltime=~s/\s/_/g;
    $ltime=~s/_+/_/g;
    $ltime=~s/^_|_$//;
    open my $lFD, '>>', "$LOGFile" or die "Unable to open LOG file |$LOGFile| for logging...$!";
    printf $lFD "\n=== __FILE__ === $ltime -> $msg\n";
    print "\n=== __FILE__ === $ltime -> $msg\n";
    close($lFD);                                                                                                             
}

1;

##</code><code>##

#script firstCaller.pl
use secondPackage;
our $LOGFile=$ARGV[0];
WriteLOG("...Script is started...\n";

##</code><code>##

package masterPakage;
use strict;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
@ISA = qw(Exporter);
@EXPORT = qw( &functions_to_be_exported );
@EXPORT_OK = qw();                                                                                  
%EXPORT_TAGS = ( );
blah..
blah..

WriteLOG(" i am inside masterPackage...\n";
blah..
blah..

1;