Improve ksh version test to catch ksh93s+

And hopefully all versions below

1 files changed, 25 insertions, 1 deletions

diff --git a/sh/shrc.d/ksh.sh b/sh/shrc.d/ksh.sh
index 5e9fee3b..befa60ee 100644
--- a/sh/shrc.d/ksh.sh
+++ b/sh/shrc.d/ksh.sh
@@ -2,7 +2,31 @@
 # configuration if it was defined or if we can find it. Bash and Zsh invoke
 # their own rc files first, which I've written to then look for ~/.shrc; ksh
 # does it the other way around.
-[ -n "$KSH_VERSION" ] || [ -n "${.sh.version}" ] || return
+
+# Unfortunately, this isn't very simple, because KSH_VERSION is set by PDKSH
+# and derivatives, and in ksh93t+ and above, but not in earlier versions of
+# ksh93.
+
+# If it's not already set, we'll try hard to set it to something before we
+# proceed ...
+if [ -z "$KSH_VERSION" ] ; then
+
+    # Do we have the '[[' builtin? Good start
+    command -v '[[' >/dev/null 2>&1 || return
+
+    # Use the '[[' builtin to test whether $.sh.version is set (yes, that's a
+    # real variable name)
+    [[ -v .sh.version ]] || return
+
+    # If it is, that's our KSH_VERSION
+    KSH_VERSION=${.sh.version}
+fi
+
+# If KSH_ENV isn't already set, set it
 [ -n "$KSH_ENV" ] || KSH_ENV=$HOME/.kshrc
+
+# Check the file named in KSH_ENV exists
 [ -f "$KSH_ENV" ] || return
+
+# Source it (finally)
 . "$KSH_ENV"