Replace ppwd with inline sed expression

Dockerfile

@@ -121,7 +121,6 @@ COPY --from=builder /output/ /
 # Add default skeleton configuration files
 COPY skel/ /
 RUN chmod 1777 /tmp && \
-    chmod 775 /usr/bin/* && \
     chmod u+s /usr/bin/ping /usr/bin/su
 
 ENV ENV="/etc/profile"

skel/etc/profile

@@ -1,6 +1,6 @@
 export PAGER='/usr/bin/less -R'
 export EDITOR='/usr/bin/vi'
-export PS1='\e[1;36m\u@\h\e[0m \e[0;32m$(ppwd)\e[0m> '
+export PS1='\e[1;36m\u@\h\e[0m \e[0;32m$(pwd | sed -E '"'s|^'\$HOME'|~|;s|(.*)/|\\1%#|;s|((^\\|/)\\.?[^/%]{1})[^/%]*|\\1|g;s|(.*)%#|\\1/|')"'\e[0m> '
 
 # Source configuration files from /etc/profile.d
 for i in /etc/profile.d/*.sh ; do

skel/usr/bin/ppwd

@@ -1,19 +0,0 @@
-#!/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"