# ***************************************************************************
# This function encode a sting in md5 hash of 32 characters. You can short
# the length with the second parameter.
#
#  @param string $1 string (required)
#  @param integer $2 length (option, default: 32)
#  @return string
#  @example:    md5 "Hello World" 8
function md5() {
  local length=${2:-32}
  local string=$( echo -n "$1" | md5sum | awk '{ print $1 }' )
  echo ${string:0:${length}}
}