oh-my-fish/plugins/jump/marks.fish

function marks
    if test (count $argv) -gt 0
        echo "Usage: marks"
    else
        set -l file_list (command ls $MARKPATH/)
        set -l mark_list
        for file in $file_list
            if test -d $MARKPATH/$file -a -L $MARKPATH/$file
                set mark_list $mark_list $file
            end
        end
        if test (count $mark_list) -eq 0
            echo "No marks currently defined."
        else
            for mark_name in $mark_list
                echo "$mark_name -> "(realpath $MARKPATH/$mark_name)
            end
        end
    end
end