CVS commit: src/bin/sh

["Robert Elz" <kre%netbsd.org@localhost>]

Module Name:    src
Committed By:   kre
Date:           Thu Feb 14 11:15:24 UTC 2019

Modified Files:
        src/bin/sh: builtins.def sh.1 var.c

Log Message:
Add the "specialvar" built-in command.   Discussed (well, mentioned
anway) on tech-userlevel with no adverse response.

This allows the magic of vars like HOSTNAME SECONDS, ToD (etc) to be
restored should it be lost - perhaps by having a var of the same name
imported from the environment (which needs to remove the magic in case
a set of scripts are using the env to pass data, and the var name chosen
happens to be one of our magic ones).

No change to SMALL shells (or smaller) - none of the magic vars (except
LINENO, which is exempt from all of this) exist in those, hence such a
shell has no need for this command either.


To generate a diff of this commit:
cvs rdiff -u -r1.25 -r1.26 src/bin/sh/builtins.def
cvs rdiff -u -r1.219 -r1.220 src/bin/sh/sh.1
cvs rdiff -u -r1.77 -r1.78 src/bin/sh/var.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.