Given a set of strings, for example:

EFgreen
EFgrey
EntireS1
EntireS2
J27RedP1
J27GreenP1
J27RedP2
J27GreenP2
JournalP1Black
JournalP1Blue
JournalP1Green
JournalP1Red
JournalP2Black
JournalP2Blue
JournalP2Green

I want to be able to detect that these are three sets of files:

• EntireS[1,2]
• J27[Red,Green]P[1,2]
• JournalP[1,2][Red,Green,Blue]

Are there any known ways of approaching this problem - any published papers I can read on this?

The approach I am considering is for each string look at all other strings and find the common characters and where differing characters are, trying to find sets of strings that have the most in common, but I fear that this is not very efficient and may give false positives.

Note that this is not the same as 'How do I detect groups of common strings in filenames' because that assumes that a string will always have a series of digits following it.

[Edited 15/09/09 to add more sample strings]