bash eternal history

gistfile1.txt

export HISTTIMEFORMAT="%s "

# this we need because we could be su'd to another user and we still want history here
chmod 666 ~/.bash_eternal_history

# reason for ~/../ is if su'ing into another user
HIST_FILE_ETERNAL=~/../goretkin/.bash_eternal_history
# add a header to indicate a new session
echo "#" $$, $USER, $(pwd), "parent:"$(ps -o ppid= -p $$), $(date), $(pwd) >> $HIST_FILE_ETERNAL


# This immediately writes the last line of the current session's history to a file
# keep track of the PID so that you can separate different terminal sessions
# this executes before the command in question, as opposed to a solution that
# modifies the $PROMPT_COMMAND variable.
# http://superuser.com/questions/175799/does-bash-have-a-hook-that-is-run-before-executing-a-command
preexec_invoke_exec () {
    if [ -n "$COMP_LINE" ]; then
      # echo "complete"
      return
    fi  # do nothing if completing
    if [ "$BASH_COMMAND" = "$PROMPT_COMMAND" ]; then
      # echo "prompt"
      return
    fi # don't cause a preexec for $PROMPT_COMMAND
    echo $$ $USER "$(history 1)" >> $HIST_FILE_ETERNAL
}
trap 'preexec_invoke_exec' DEBUG