--- a/.bash_prompt	Sat Mar 23 21:15:08 2019 +0800
+++ b/.bash_prompt	Thu Apr 11 01:13:54 2019 +0800
@@ -57,11 +57,11 @@
     fi
 
     PS1="\
-${K}[${RESET}${TIME} \\u@\\h \
+${K}[${RESET}${TIME} ${debian_chroot:+${Y}(c)${RESET} }\\u@\\h \
 ${RETCODE}\\W${VENV}${HG_INFO}${GIT_INFO}${K}]${RESET}\
 ${PROMPT_COLOR}\\\$${RESET} "
 
-    PS1="\\[\\033]0;\\u@\\h: \\W\\007\\]$PS1"
+    PS1="\\[\\033]0;${debian_chroot:+($debian_chroot) }\\u@\\h: \\W\\007\\]$PS1"
 }
 
 function _upsearch {

--- a/.bashrc	Sat Mar 23 21:15:08 2019 +0800
+++ b/.bashrc	Thu Apr 11 01:13:54 2019 +0800
@@ -24,6 +24,11 @@
 # make less more friendly for non-text input files, see lesspipe(1)
 [ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"
 
+# set variable identifying the chroot you work in (used in the prompt below)
+if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
+    debian_chroot=$(cat /etc/debian_chroot)
+fi
+
 [ -x /usr/bin/keychain ] && eval "$(keychain --eval --quiet)"
 
 if [ -x /usr/bin/dircolors ]; then