Suppose you wanted to do the equivalent of the following Unix shell code on the mainframe in JCL:

head -1 < UT128.SYSOUT.EXPECTED > $TID.$CID.SYSOUT.ACT
head -1 < UT128.COBPRINT.EXPECTED > $TID.$CID.COBPRINT.ACT

Here’s the JCL equivalent of this pair of one-liners:

There are probably shorter ways to do this, but the naive way weighs in at 22:2 lines for JCL:Unix — damn!

I can’t help but to add a punny comment that knowing JCL must have once been really good JOB security.