zsh: Improve chpwd behaviour

zsh/.zshrc

@@ -94,12 +94,12 @@ bindkey "^K"        kill-line           # Ctrl + k
 bindkey "^U"        backward-kill-line  # Ctrl + u
 
 # save path on cd (chpwd is a zsh hook) and spawned subshell
-function chpwd {
+function _chpwd {
   pwd > ~/.last_dir
 }
 
-if [[ $SHLVL -ge 3 ]]; then
-  chpwd
+if [[ $SHLVL -gt 3 ]]; then
+  _chpwd
 fi
 
 # restore last saved path on launch
@@ -107,6 +107,10 @@ if [[ -f ~/.last_dir ]]; then
   cd $(cat ~/.last_dir)
 fi
 
+function chpwd {
+  _chpwd
+}
+
 # save path on quiting nnn (and alias it to 'n')
 function n {
     # Block nesting of nnn in subshells