Add ppwd script to skel directory

Dockerfile

@@ -119,11 +119,9 @@ SHELL ["/bin/sh", "-exc"]
 
 COPY --from=builder /output/ /
 # Add default skeleton configuration files
-ADD skel/* /etc/
-RUN chmod 1777 /tmp
-
-ADD https://gist.githubusercontent.com/frebib/2b4ba154a9d62b31b1edcb50477e7f01/raw/647c3f8ee4dc7e325cd41f40fe47735f75a7f607/ppwd.sh /usr/bin/ppwd
-RUN chmod 755 /usr/bin/ppwd
+COPY skel/ /
+RUN chmod 1777 /tmp && \
+    chmod 775 /usr/bin/*
 
 ENV ENV="/etc/profile"
 ENV PATH=/usr/local/sbin:/usr/local/bin:/usr/bin 

skel/usr/bin/ppwd

@@ -0,0 +1,19 @@
+#!/bin/sh
+set -e -o pipefail
+
+dir="$(echo -n "${1:-$PWD}" | sed "s|$HOME|~|")"
+
+if [ "$dir" = '~' -o "$dir" = '/' ]; then
+    echo "$dir"
+    exit 0
+fi
+
+parts="$(echo "$dir" | tr '/' '\n' | sed '$d')"
+last="$(echo "$dir" | tr '/' '\n' | tail -n 1)"
+
+for d in "$parts"; do
+    out="$out$(echo "$d" | sed -E '/^\./s/^(.{2}).*/\1/;/^[^\.]/s/^(.{1}).*/\1/')\n"
+done
+
+echo -en "$out" | tr '\n' '/'
+echo "$last"