lib.cdstack

#! /bin/bash

function cdstack_enable ()
{
  cdevent_push_pre __cdstack_cd
}

function __cdstack_cd ()
{
  # shellcheck disable=SC2034
  declare pushd_silent=t
  case "$1" in
    - ) builtin pushd +1 >/dev/null
        return 1
        ;;
    + ) builtin pushd -0 >/dev/null
        return 1
        ;;
    -s ) __cdstack_show_stack
         return 1
         ;;
    -c* ) __cdstack_clear_stack ${1#-c}
          __cdstack_show_stack
          return 1
          ;;
    -* ) declare i=${1#-}
         if [ -z "${i##[0-9]*}" ]
         then
           builtin pushd +$i >/dev/null
         fi
         return 1
         ;;
  esac
  declare i=1 dirs="$(dirs -l)"
  builtin pushd ${1:-~} >/dev/null 2>/dev/null || {
    return 0
  }
  for d in $dirs
  do if [ "$d" = "$PWD" ]
     then builtin popd +$i >/dev/null; break; fi
     let i=i+1
  done
  return 1
}

function __cdstack_clear_stack ()
{
  case "$1" in
     ..* ) declare j=${1#..}
           if [ -n "${j##[0-9]*}" ]; then return 1; fi
           let "j=j+1"
           while let "j>0"
           do builtin popd +0 >/dev/null 2>/dev/null || return; let "j=j-1"; done
           ;;
     *.. ) declare i=${1%..}
           if [ -n "${i##[0-9]*}" ]; then return 1; fi
           if [ $i -eq 0 ]; then let "i=1"; fi
           while builtin popd +$i >/dev/null 2>/dev/null; do : nothing; done
           ;;
    *..* ) declare i=${1%..*} j=${1#*..}
           if [ -n "${i##[0-9]*}" ] || [ -n "${j##[0-9]*}" ]
           then return; fi
           let "j=j-i+1"
           while let "j>0"
           do builtin popd +$i >/dev/null 2>/dev/null || return; let "j=j-1"; done
           ;;
      '' ) while builtin popd +1 >/dev/null 2>/dev/null; do : nothing; done
           ;;
       * ) declare i=$1
           if [ -n "${i##[0-9]*}" ]; then return 1; fi
           builtin popd +$i >/dev/null 2>/dev/null || return
           ;;
  esac
  return 0
}

function __cdstack_show_stack ()
{
  declare -i i=0
  for d in $(dirs -l)
  do echo -e "[$i]\t$d"; let "i=i+1"; done
  return 0
}