|Think about Loose Coupling|
Design hints for a file processorby PhilHibbs (Hermit)
|on Jul 07, 2008 at 11:54 UTC||Need Help??|
PhilHibbs has asked for the
wisdom of the Perl Monks concerning the following question:
I have a script that reads a structured file, looks for various elements, and does a few search/replace operations, writes out a translated version of the file, and also records various bits of useful information and writes them out to separate files.
The file in question is an export from IBM DataStage, which is a graphical data processing tool. The file contains the "jobs" that we have created, most of which consist of reading and writing CSV files and hashed files.
The design for the script is rather haphazard at the moment, built up over time from a very simple single search-replace operation into something of a nine-headed hydra of a script.
I'm after some tips about how to go about rewriting this script. It needs to be able to identify various elements in the file based on context. For instance, a chunk might look like this:
This is an easy one - any line starting with three spaces and the word "Identifier" is the Job Name.
Here's a more complex example:
From here, I need to pick up the Category "1.FSS\\2.AP\\6.CDBS\\1.Vendors\\3.Reports", and all of the parameter Name and Default values, "ROOT" = "/home/migration/Dev", "SITE" = "CDBS", etc.
There are some more complex cases, where I need to pick up one or two paths from a DSRECORD section, and then one or more pairs of filenames from DSSUBRECORD sections.
Any hints on how I should structure this program, so that it is clear and maintainable to someone who is new to Perl? Any modules that would make this easier?
By way of an apology, it's been a long time since I did any serious procedural or OO programming, 10 years ago I'd have been able to do this with my eyes closed.