added last command error status to prompt

home/.bashrc

@@ -66,7 +66,7 @@ if [ -n "$force_color_prompt" ]; then
 fi
 
 if [ "$color_prompt" = yes ]; then
-    PS1=' \[\033[01;36m\]\D{%Y%m%d-%H:%M:%S}\[\033[00m\] ${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
+    PS1='\[\033[01;36m\]\D{%Y%m%d-%H:%M:%S}\[\033[00m\] ${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
 else
     PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
 fi
@@ -81,6 +81,58 @@ xterm*|rxvt*)
     ;;
 esac
 
+PROMPT_COMMAND=__prompt_command    # Function to generate PS1 after CMDs
+
+__prompt_command() {
+    local exit_code="$?"                # This needs to be first
+    PS1=""
+
+    local RCol='\[\e[0m\]'
+
+    local Red='\[\e[0;31m\]'
+    local Gre='\[\e[0;32m\]'
+    local BYel='\[\e[1;33m\]'
+    local BBlu='\[\e[1;34m\]'
+    local Pur='\[\e[0;35m\]'
+
+    
+    local last_command_status=''
+    local last_command_status_color=''
+    local status_prompt_mode='exit-code'
+    case "$status_prompt_mode" in
+        'exit-code')
+            last_command_status="${exit_code}"
+            if [ $exit_code = 0 ]; then
+                last_command_status_color="${Gre}"
+            else
+                last_command_status_color="${Red}"
+            fi
+            ;;
+        'pipe-status')
+            # warning : this mode doesn't seem to be working
+            # Bash variable PIPESTATUS provides more information about the last executed command or pipe. ${PIPESTATUS[@]} will be a string of zeroes like 0 0 0 in case all commands were executed correctly, otherwise it will have non zeroes like 0 127 1. One can check for success with if $(echo ${PIPESTATUS[@]} | grep -qEe '^0( 0)*$'); then echo "good"; else echo "bad"; fi. – 
+            last_command_status="${PIPESTATUS[@]}"
+            if $(echo ${PIPESTATUS[@]} | grep -qEe '^0( 0)*$')
+            then
+                # echo "good"
+                last_command_status_color="${Gre}"
+            else
+                # echo "bad"
+                last_command_status_color="${Red}"
+            fi
+            ;;
+        *)
+            last_command_status_color="${Red}"
+            last_command_status="unexpected value for status_prompt_mode: $status_prompt_mode"
+            ;;
+
+    esac
+
+    PS1+="[${last_command_status_color}${last_command_status}${RCol}]"
+
+    PS1+='\[\033[01;36m\]\D{%Y%m%d-%H:%M:%S}\[\033[00m\] ${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
+}
+
 # enable color support of ls and also add handy aliases
 if [ -x /usr/bin/dircolors ]; then
     test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"