[TUHS] practice of aliasing C compiler with occ?

[Nigel Williams]

We've been recovering a 1980s programming language implemented using a
mix of Pascal and C that ran on 4.1 BSD on VAX.

The Makefile distributed to around 20+ sites included these lines for
the C compiler.

CC=     occ
CFLAGS= -g

It seems there was a (common?) practice of keeping around the old C
compiler when updating a BSD system and occ was used to reference it.

Anyone care to comment on this observation? was it specific to
BSD-land? how was the aliasing effected, a side-by-side copy of the
compiler pieces? As at 4.1 BSD the C compiler components were in /lib
(Pascal though was in /usr/lib).

# ls -l /lib
total 467
-rwxr-xr-x 1 root      25600 Jul  9  1981 c2
-rwxr-xr-x 1 root      89088 Jul  9  1981 ccom
-rwxr-xr-x 1 root      19456 Jul  9  1981 cpp
-rwxr-xr-x 1 root        199 Mar 15  1981 crt0.o
-rwxr-xr-x 1 root      40960 Jul  9  1981 f1
-rwxr-xr-x 1 root      62138 Jul  9  1981 libc.a
-rwxr-xr-x 1 root        582 Mar 15  1981 mcrt0.o