axel_histfile.sh

#!/bin/zsh

# relative history
relative_histfile() {
    searchdir="$(readlink -f $PWD)";

    # default values
    if [ -z "$HISTDIR" ]; then
        HISTDIR="$HOME/.histfiles/";
    fi
    if [ -z "$HISTFILE_DEFAULT" ]; then
        HISTFILE_DEFAULT="$HOME/.histfile"
    fi;

    # find first histfile starting from pwd up to /
    while true; do
        histtarget="${HISTDIR}/${searchdir//\//%}"
        if [ -e "$histtarget" ] || [ "$searchdir" = "/" ]; then
            break;
        fi;
        searchdir="$(readlink -f "$searchdir/..")";
    done;

    # load relative history or default one
    if [ "$searchdir" = "/" ]; then
        if [ "$HISTFILE" != "$HISTFILE_DEFAULT" ]; then
            echo "> load default history";
            fc -Pp "$HISTFILE_DEFAULT";
        fi;
    else
        echo "> load history for $searchdir";
        fc -Pp "$histtarget";
    fi;
}
chpwd_functions+=(relative_histfile);
relative_histfile;