[Info-vax] Porting logical name applications to Unix

[ChaosLess]

the 'environment' variable list is a char* array passed to the process
in data space at startup.
that array used to have a limited amount of preallocated space too,
would guess that is still true.
it is a simple means to pass information 1-way from parent to child in
the process tree.
is even possible to get ahold of that array (envp), reallocate it, and
(shudder) to update it dynamically.


and compared to VMS logical name handling, well it just doesn't
compare - as it was never intended for the range of features in
logical name handling.
nor does it offer the integration that is found on VMS with lnm
handling.  you can't even open("$HOME/.myfile") from the crtl, for
example.
which was my original point that, if you want logical name equivalent
functionality on unix then it is a separate thing (and why we'd
written it).

JF said he was looking for native features to use on unix.
hopefully there's been helpful examples in this thread of how to
accomplish some of the simpler things in other ways.
there are plenty of other (mostly shell) features for pathname
substitution that could help, depending on specific requirements.

for generalised features and well rounded integration into dcl shell,
system services, and language runtimes - logical names are a fantastic
feature.

we use them even in non-VMS applications and in new developments
because you get so much functionality out-of-the-box.
systems we've migrated continue using logical names from the unix
shell and the migrated vms applications because their integration and
interrelated features are so prevalent throughout.