#!/usr/bin/perl

use strict();

main();

sub main
{
    my $FileHandle = CreateFile1("test1.txt");
    print $FileHandle "hello";
    print FILEHANDLE " world";
    close $FileHandle;

    my $FileHandle2 = CreateFile2("test2.txt");
    print $FileHandle2 "hello file 2";
    close $FileHandle2;
}

sub CreateFile1
{
    my ($strFileName) = @_;

    #FILEHANDLE is globally accessible
    open FILEHANDLE, ">" . $strFileName;
    return \*FILEHANDLE;
}

sub CreateFile2
{
    my ($strFileName) = @_;

    #$FileHandle is private
    open my($FileHandle), ">" . $strFileName;

    return $FileHandle;
}