Replace String A With String B But Not If It’s Part Of String A1

(Originally posted 2008-07-31.)

As I mentioned in this blog post DFSORT just shipped a new FINDREP function to do “find and replace”.

I mentioned an example of where I might use it to replace SMFIDs in SMF records. That example generally works well.

But suppose (say, for SMF 42-6 Data Set Performance records) I want to replace “SYS1” with “MVSA” but don’t want to replace “SYS1.” with “MVSA.”.

There’s something useful about FINDREP that saves the day: Only the first match is used. So consider the following FINDREP example:

  OPTION COPY                                                
  INREC FINDREP=(INOUT=(C'SYS1.',C'SYS1.',C'SYS1',C'MVSA'))
  

With this code any data set references of the form “SYS1.” are transformed to themselves – and the cursor moves past them – whereas any other “SYS1” reference is transformed to “MVSA”.

It makes sense to put the most restrictive find string first. Otherwise the following wouldn’t work…

   OPTION COPY                                              
   INREC FINDREP=(INOUT=(C'SYS1.MODIFYME',C'MVSA.MODIFYME',
     C'SYS1.',C'SYS1.',
     C'SYS1',C'MVSA'))

which will change “SYS1.MODIFYME” into “MVSA.MODIFYME” but no other “SYS1.” string (unless it starts with “SYS1.MODIFYME”).

Of course, given you can use FINDREP as part of IFTHEN there’s a lot more you can do with it. But for now I just wanted to point out the “first hit wins” characteristic that can be useful.