Split ~/.shrc off stub ~/.shinit file

NetBSD sh(1) and possible others don't tolerate a `return` short-circuit
for ENV, which means that because that implementation also sources ENV
if set regardless of whether the shell is interactive or not, all of the
interactive stuff in ~/.shrc and ~/.shrc.d gets uselessly sourced and
loaded up for non-interactive invocations of sh(1).

To work around this, I've set ENV to be a new ~/.shinit file instead,
which sources the ~/.shrc file only if the shell is interactive.
~/.shinit is the filename suggested in the man page for NetBSD sh(1) and
Debian dash(1) as well.

NetBSD's documented behaviour seems to be contrary to POSIX 2003:

> ENV: This variable, when and only when an interactive shell is
> invoked, shall be subjected  to  parameter expansion (see Parameter
> Expansion ) by the shell, and the resulting value shall be used as a
> pathname of a file containing shell  commands to  execute in the
> current environment.

No matter; this works fine, and makes non-interactive invocations of
sh(1) on NetBSD much faster.

1 files changed, 0 insertions, 6 deletions

diff --git a/sh/shrc b/sh/shrc
index 3e03313c..0e1382aa 100644
--- a/sh/shrc
+++ b/sh/shrc
@@ -1,9 +1,3 @@
-# Make sure the shell is interactive
-case $- in
-    *i*) ;;
-    *) return ;;
-esac
-
 # Don't let anyone write(1) to my terminal
 command -p mesg n