File Find/Replace with the replacement coming from part of earlier matched string

navinc has asked for the wisdom of the Perl Monks concerning the following question:

I have about 30,000 log files which need to be prepped for ingest into a log processor. Here's what the format of the files looks like

PCName: Foo1
Command1:dfie

Command2:dfo

Command3:dfum

PCName: Foo2

Command1:dfie

Command2:dfo

Command3:dfum
[download]

The log processor needs the PCName to appear as the line before each Command. Hence the output of the scripts should be

PCName: Foo1
Command1:dfie

PCName: Foo1
Command2:dfo

PCName: Foo1
Command3:dfum

PCName: Foo2
Command1:dfie

PCName: Foo2
Command2:dfo

PCName: Foo2
Command3:dfum
[download]

Any ideas on how to do this in an efficient manner?

The list of commands varies from a couple to dozens for some PC's. Also for brevity I've left out the fact that the results of the commands are also present.

I've tried to use the solution put forth here http://docstore.mik.ua/orelly/perl/cookbook/ch09_11.htm to divide the file into sections by PCName and then further into sections divided by Commands and then modify the command sections to add the PCName prefix.

The files are upto 1MB max so slurping is fine. However I want to ensure that the performance holds up. Also wanted to check if there is an easier way to do this using some Perl Modules.

Thanks.

Back to Seekers of Perl Wisdom