[TUHS] A question about ls(1)

[Anthony Martin]

>From at least V2 to V6, the ls(1) command would not
show directory entries whose names began with a '.'
unless the -a flag was supplied.

This was changed in V7: only the directory entries
for "." and ".." would be skipped by default.

All further versions of Research Unix retain the
convention of V7 and Plan 9 ultimately made it
unnecessary. However, BSD and its descendants did
not follow suit. Instead, they continued behaving
like V6 with an additional -A flag to emulate V7.

Was the initial behavior intentional or just a
matter of expediency?

Who made the change and what was their motivation?
Was it a reaction to the intentional hiding of what
came to be known as "dot files"?

Thanks,
  Anthony