Finnish personal identity code calculator/generator

hetu.sh

#!/bin/bash
################################################################################
# hetu.sh - finnish personal identity code calculator/generator
#
# by pyllyukko - https://github.com/pyllyukko
#
# more info:
# https://secure.wikimedia.org/wikipedia/en/wiki/National_identification_number#Finland
#
################################################################################
#[ ${BASH_VERSINFO[0]} -eq 4 ] && shopt -s compat31
shopt -s nocasematch
declare -r  MATRIX="0123456789ABCDEFHJKLMNPRSTUVWXY"
declare -ar SEX=("woman" "man")
declare -a  DAYS=(31 28 31 30 31 30 31 31 30 31 30 31)
################################################################################
function usage() {
  cat 0<<-EOF
	usage: ${0##*/} DDMMYYCZZZ||YYYY||DDMMYY

	examples:
	  ${0##*/} 1980
	  ${0##*/} 010101-001
	  ${0##*/} 010101
EOF
  return 0
} # usage()
################################################################################
function calculate() {
  local DDMMYYCZZZ
  local ZZZ
  local DAY
  local MONTH
  if [ ${#} -ne 1 -o ${#1} -ne 10 ] || \
     [[ ! ${1} =~ ^[0-3][0-9][01][0-9]{3}[-+a][0-9]{3}$ ]] || \
     [ ${1:2:2} -gt 12 -o ${1:2:2} -lt 1 ]
  then
    echo "${FUNCNAME}(): error!" 1>&2
    return 1
  fi
  DDMMYYCZZZ="${1}"
  ZZZ="${DDMMYYCZZZ:7:3}"
  DAY=`expr "${DDMMYYCZZZ:0:2}" : '^0\?\([0-9]\+\)$'`
  MONTH=`expr "${DDMMYYCZZZ:2:2}" : '^0\?\([0-9]\+\)$'`
  #echo "${FUNCNAME}(): DEBUG: DAY=\"${DAY}\""

  set -- ${1/[-Aa+]/}
  # here be bug!
  [ ${DAY} -gt ${DAYS[$[${MONTH}-1]]-0} -o ${DAY} -lt 1 ] && {
    return 3
  }
  echo "${DDMMYYCZZZ}${MATRIX:$[${1#0}%${#MATRIX}]:1} ${SEX[$[${ZZZ:2:1}%2]]}"
  return 0
} # calculate()
################################################################################
function generate() {
  # $1 = year
  # this function still needs to be finished...
  local DAY
  local MONTH
  for MONTH in {1..12}
  do
    for DAY in {1..31}
    do
      [ ${DAY#0} -gt ${DAYS[ $[ ${MONTH#0} - 1 ] ]} ] && continue
      # according to cia world factbook (9.9.2010):
      #   population = 5,250,275 (July 2010 est.)
      #   birth rate = 10.38 births/1,000 population (2010 est.)
      #   ...that's roughly 149 per day. of course that's not the whole truth,
      #   but we'll go with that for now.

      # personal identification number
      for PIN in {1..149}
      do
	[ ${#PIN} -eq 1 ]	&& PIN="00${PIN}"
	[ ${#PIN} -eq 2 ]	&& PIN="0${PIN}"
	[ ${#DAY}   -eq 1 ]	&& DAY="0${DAY}"
	[ ${#MONTH} -eq 1 ]	&& MONTH="0${MONTH}"
	calculate "${DAY}${MONTH}${1:2:2}${C}${PIN}"
      done
    done
  done
  return 0
} # generate()
################################################################################
function check_leap_year() {
  if [[ ! ${YY} =~ ^[0-9]{2}$ || ! ${CENTURY} =~ ^[0-9]{4}$ ]]
  then
    echo "${FUNCNAME}(): error!"
    return 1
  fi
  [ $[(${YY#0}+${CENTURY})%4] -eq 0 -a \
    $[(${YY#0}+${CENTURY})%100] -ne 0 -o \
    $[(${YY#0}+${CENTURY})%400] -eq 0 \
  ] && {
    #echo "${FUNCNAME}(): DEBUG: $((${CENTURY}+${YY#0})) is a leap year"
    DAYS[1]=29
  }
  return 0
} # check_leap_year()
################################################################################
if [ ${#1} -eq 4 ]
then
  case "${1:0:2}" in
    "18") C="+" ;;
    "19") C="-" ;;
    "20") C="A" ;;
    *)
      echo "invalid century!" 1>&2
      exit 1
    ;;
  esac
  CENTURY=$((${1:0:2}*100))
  YY="${1:2:2}"
  check_leap_year
  generate "${1}"
elif [ ${#1} -eq 10 ]
then
  YY="${1:4:2}"
  C="${1:6:1}"
  case "${C}" in
    "a") CENTURY=2000 ;;
    "+") CENTURY=1800 ;;
    "-") CENTURY=1900 ;;
    *)
      echo "invalid input!" 1>&2
      exit 1
    ;;
  esac
  check_leap_year
  calculate "${1}"
elif [ ${#1} -eq 6 ]
then
  # TODO: 002-899
  for I in {100..300}
  do
    #if [ $(( I % 2 )) = 1 ] # woman only
    if [ $(( I % 2 )) = 0 ] # man only
    then
      continue
    fi
    calculate "${1}-${I}"
  done
else
  usage
  exit 1
fi
exit 0