Linux command line Directory Navigation

export MARKPATH=$HOME/.marks
function jump { 
    cd -P "$MARKPATH/$1" 2>/dev/null || echo "No such mark: $1"
}
function jopen { 
    thunar  "$MARKPATH/$1" 2>/dev/null || echo "No such mark: $1"
}
function mark { 
    mkdir -p "$MARKPATH"; ln -s "$(pwd)" "$MARKPATH/$1"
}
function unmark { 
    rm -i "$MARKPATH/$1"
}
function marks {
    ls -l "$MARKPATH" | sed 's/  / /g' | cut -d' ' -f9- | sed 's/ -/\t-/g' && echo
}
_completemarks() {
  local curw=${COMP_WORDS[COMP_CWORD]}
  local wordlist=$(find $MARKPATH -type l -printf "%f\n")
  COMPREPLY=($(compgen -W '${wordlist[@]}' -- "$curw"))
  return 0
}
 
complete -F _completemarks jump unmark

cd ~/some/very/deep/often-used/directory
mark deep
 
# This adds a symbolic link named deep to the directory ~/.marks.
# To jump to this directory, type the following from any place in the filesystem:
jump deep
 
# To remove the bookmark (i.e., the symbolic link), type:
unmark deep
 
# You can view all marks by typing:
marks