# Part of the solution to Questions 1 & 3, Chapter 5 of# "Learning the bash Shell".## Cameron Newham, July 1997.recdir (){  local char  local thistab  if [ $# -ne 0 ]; then    echo -e $tab$vertical  fi  thistab=$tab$vertical$horizontal  tab=$tab$vertical$singletab  for file in "$@"; do    if [ -d $dir/$file ]; then      char="/"    else      char=""    fi    echo -e $thistab$file$char    dir=$dir/$file    if [ -d $dir ]; then      recdir $(command ls $dir)    fi    dir=${dir%/*}  done  tab=${tab%|\\t}  echo -e $tab}recls (){    singletab="\t"    vertical="|"    horizontal="-------"    for tryfile in "$@"; do    if [ -d $tryfile ]; then      echo -e $tryfile"/"    else      echo -e $tryfile    fi    if [ -d $tryfile ]; then      dir=$tryfile      recdir $(command ls $tryfile)    fi    done    unset dir singletab tab vertical horizontal}