[arch-general] bash variable PS1 confuses the terminal somehow

[清显]

13 PROMPT_COMMAND='
14         if (($?)); then
15                 warn="^[[31mWARNING^[[m"
16         else
17                 warn=
18         fi
19         date=`date`
20         PS1="\[^[[s\]\[^[[$(($COLUMNS-28))C\]\[^[[0;33m$date\]\[^[[u\]\[^[[0;31m$warn\]\[^[[0;32m[\]\[^[[1;33m\u\]\[^[[0;32m@\]\[^[[1;36m\w\]\[^[[0;32m]\$\]
21 '

  i changed PROMPT_COMMAND to this as you said, it fixes what i mentioned earlier, but produces more problem, like when i type one character and then use BACKSPACE to delete it, the entire promt is gone, and again bring me to the begining of the line, also when i use ^R to search for history command, the prompt is destroyed too...