use strict;
my $str = '[01/30/2018 15:01:24] [Visma.Workflow.Server.exe] Off
[CompanyDatabaseUpgrader.CheckAndUpgradeCompanyDb::0] ThreadId: 12 ThreadName:
Initializing of ERP client complete. Logged from: CompanyDatabaseUpgrader.CheckAndUpgradeCompanyDb (0)
';
my $regex = qr/(\[[^\]]+\]\s+\[[^\]]+\]\s+\w+)\s+(\[[^\]]+\])\s+(ThreadId:\s+\d+)\s+(ThreadName:)\s+(.+?)\s+(Logged from:.+)\s+/p;
my $subst = '\\1, \\2,\\n\\3,\\n\\4 \\5,\\n\\6,';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html