Improved ssh session detection in zsh's `powermeli` theme checking if an ancestor process is named `sshd`

zsh/.config/zsh/plugins/powermeli.zsh-theme

@@ -28,13 +28,40 @@ prompt_segment() {
   unset separator
 }
 
+# Return the first ancestor PID of the PID of this process with the name issued
+# From: https://unix.stackexchange.com/a/459007
+# TODO: Consider reading from `/proc/<pid>/*` using only POSIX shell builtins
+# Note: the `/proc` is not guaranteed to be on all unices (see BSD, Mac...)
+# See:
+# - https://stackoverflow.com/a/50457487
+# - https://stackoverflow.com/a/1525673
+get_apid() {
+  ps -Ao pid= -o ppid= -o comm= |
+    awk -v p="$$" -v ancestor="$1" '
+      {
+        pid = $1; ppid[pid] = $2
+        sub(/([[:space:]]*[[:digit:]]+){2}[[:space:]]*/, "")
+        name[pid] = $0
+      }
+      END {
+        while (p) {
+          if ( name[p] == ancestor ) {
+            print p, name[p]
+            exit
+          }
+          p = ppid[p]
+        }
+      }'
+}
+
 prompt_context() {
   if [ $(id -u) -eq 0 ]; then
     prompt_segment "$SEGMENT_SEPARATOR" black yellow
   else
     prompt_segment "$SEGMENT_SEPARATOR" black default
   fi
-  if [ -z ${SSH_CLIENT+x} ]; then
+  # Check if inside an ssh session, also if using `sudo su`
+  if [ -z ${SSH_CLIENT+x} ] && [ -z ${SSH_TTY+x} ] && [ -z "$(get_apid sshd)" ]; then
     PROMPT_LINE="$PROMPT_LINE %n "
   else
     PROMPT_LINE="$PROMPT_LINE %n%{%F{blue}%}@%{%F{cyan}%}%m "
@@ -122,7 +149,7 @@ build_prompt() {
   unset OLD_BG OLD_SEP
   printf "%s%s " "%{%f%b%k%}" "$PROMPT_LINE"
   unset PROMPT_LINE
-  unset -f prompt_segment prompt_status prompt_virtualenv prompt_context prompt_git
+  unset -f prompt_segment prompt_status prompt_virtualenv prompt_context prompt_git get_apid
 }
 
 setopt prompt_subst