Zsh history tweaking

ZSH time travel experiment - working! At last!

freeze_hist() {
        fc -p # pop current history into stack
        HISTFILE=`pwd`/.zsh_custom_history
        SAVEHIST=10000
        HISTSIZE=10000
}

unfreeze_hist() {
        fc -p `pwd`/.zsh_custom_history
        HISTFILE=`pwd`/.zsh_custom_history
        SAVEHIST=10000
        HISTSIZE=10000
}

HBD="/home/pielgrzym/var/hist_test"
HBD_LOCK=0

chpwd() {
        if [[ $PWD = $HBD* && $HBD_LOCK -eq 0 ]]
        then
                HBD_LOCK=1
                echo "Setting the lock"
                if [[ -s .zsh_custom_history && -r .zsh_custom_history && -w .zsh_custom_history ]] 
                then
                        echo "Unfreezing history!"
                        unfreeze_hist
                fi
        fi
        if [[ $PWD != $HBD* && $HBD_LOCK -ne 0 ]]
        then
                HBD_LOCK=0
                echo "Resetting the lock"
                fc -P
                echo "Restoring global history"
        fi
}