# unset possible system-defined aliases.
unalias l ll lll llll la lla &> /dev/null
unset l ll lll llll la lla &> /dev/null

# list files in dir.
l()
{
  ls -lhv --si --group-directories-first "$@"
}

# list last modified files first.
ll()
{
  ls -lhvtr --si "$@"
}

# list files in tree structure.
# usage: lll [DEPTH] [DIRS]
lll()
{
  local IFS=$'\n'
  local depth="${1}"
  local target=("${@:2}")

  [[ "${target}" = "" ]] && target="."
  [[ "${depth}" = "" ]] && depth=666
  [[ "${depth}" = "-" ]] && depth=666

  tree -a -L "${depth}" -- "${target[@]}"
}

# list files recursively.
llll()
{
  ls -RlAhv --si --group-directories-first "$@"
}

# list all files in dir, incl. hidden files.
la()
{
  ls -lAh --si --group-directories-first "$@"
}

# list all files in dir, incl. hidden files, sorted by mtime.
lla()
{
  ls -lAhtr --si "$@"
}

# export.
export -f l ll lll llll la lla