On 1 Nov 2017, at 03:23, Dave Horsfall
A previous boss insisted that all his support staff learn ED, because one day it might be
the only editor available on a trashed box (you can't mount /usr etc).
That's happened to me relatively recently (I know ed just well enough to get machines
out of that state).
Of course nowadays you can't rely on the thing called 'ed' being
'ed': I know someone who lives in ed but can't run it on some machines
because it relies on something in /var somewhere being writable, which it isn't.
I've always thought that the *whole point* of ed was that it did not rely on vast
tracts of the system actually being there, still less beng functional. This person now
has to edit things with cat (which, in some future release, will probably start assuming
that there's a configured ipv6 interface or something, because why would that ever
not be true?).