Unix cmd names obscure?

[rcd at opus.UUCP]

> "... once the tape is done, you can run a standard IBM utility
>  like IEBGENER to print it on a high speed printer."
> 
> And they say Unix command names are obscure...

Not half, they aren't!  If you think the description above is cryptic,
realize that it's only a glimpse into a bizarre universe...

IEBGENER is the utility you use to copy things.  Don't be confused by the
fact that there is an IEBCOPY, which does something else entirely.  And to
delete files, you use IEFBR14.  This wonderfully mnemonic name is derived
from a magic IBM prefix (IEF) and a branch instruction (Branch Register 14)
which is effectively a do-nothing program, since register 14 is the
standard place for the "return address" of a main program.  Huh?  Delete a
file...oh yeah, we were talking about that...well, you delete files as a
side-effect of running a program, so IEFBR14 gives you a harmless program
which can be run for its side effect.

[Interesting side-side issue:  You may have heard the quip that "Every
program has at least one bug and can be shortened by at least one
instruction"--from which, by induction, one can deduce that every program
can be reduced to one instruction which doesn't work.  IEFBR14, if written
as the obvious, single-instruction program "  BR 14", does NOT work.
Reason:  It fails to set a proper value for its return code, which means
that it may fail mysteriously.  An entertaining rumor has it that this bug
actually existed in IEFBR14 once.  But don't get too cocky--the same bug
also exists in the UNIX world, since many C programs terminate by falling
out the bottom of the main program and most C startup routines simply take
whatever garbage return value this produces as the exit status of the
program.]
-- 
Dick Dunn	{hao,ucbvax,allegra}!nbires!rcd		(303)444-5710 x3086
   ...Are you making this up as you go along?