steveej-laptop/system: rework PS1

configuration/steveej-laptop/system.nix

@@ -30,6 +30,19 @@
   programs.bash = {
     enableCompletion = true;
     promptInit = ''
+      function exitstatus() {
+        if [[ $? -eq 0 ]]; then
+          printf '✓'
+        else
+          printf '✗'
+        fi
+      }
+      function nixshellEval {
+        if [[ "$1" != "" ]]; then
+          printf "»$1« "
+        fi
+      }
+      function setPS1 {
         if test "$TERM" != "dumb"; then
           # Provide a nice prompt.
           BLUE="\[\033[0;34m\]"
@@ -39,11 +52,13 @@
 
           PROMPT_COLOR=$RED
           let $UID && PROMPT_COLOR=$GREEN
-            PS1=" $BLUE\W/ $PROMPT_COLOR\\$ $NO_COLOR"
+          PS1="$PROMPT_COLOR\u$NO_COLOR@\h \$(exitstatus) \$(nixshellEval $1)$BLUE\w$NO_COLOR\n$PROMPT_COLOR\\$ $NO_COLOR"
           if test "$TERM" = "xterm"; then
             PS1="\[\033]2;\h:\u:\w\007\]$PS1"
           fi
         fi
+      }
+      setPS1
     '';
   };