Three common reasons I can think of:

1. No compilers for HLLs — systems run turn-key apps and no development is done. CL is “free” and requires no additional expense for simple things like “look at the 54th record”.

2. No available skills — learning RPG (or COBOL or C or whatever) can take a few days (weeks, months), which might not be quick enough if some simple data is needed very soon.

3. Curiosity — sometimes you just want to learn the capabilities of a language; until someone comes out and says “You can’t do it,” it’s hard to know that you aren’t just missing an instruction or a parameter.

Of course, the reason this thread is awake again is just the spam post that had no valid info at all.

Tom

CL / JCL is a control language. its purpose is to control the processing, not DO the processing.
If you want to know the way to somewhere you use a map, not a newspaper.

You mention RPG, so you know how to use it for a keyed access retrieve – just do so.
Define the record as a structure to be passed back as parameters, In the CLP define the file to get an identical set of field names.

call the RPG, pass back the record data, make a control decsion.
The LDA (Local Data area) was mentioned. You could use it, but why do so. If you need the data from the xth record, just get it the most efficient way, and give the CL all or some of it that’s needed.

You could, in CLP read the file sequentially until you find the record you need. Just about possible for 100 records, but again, it will be quicker, more certain, and cost less to use the languages for their intended purpose.