# Mon Oct 18 04:32:34 EDT 2004
# NAME: randomword
# Copyright 2004 Chris F.A. Johnson
# Released under the terms of the GNU General Public License

description="Generate random passwords; length and characters may be specified"

_interspace()
{
    w="$@"
    _INTERSPACE=
    while [ ${#w} -gt 0 ]
    do
      w_=${w#?}
      _INTERSPACE="$_INTERSPACE ${w%"$w_"}"
      w=$w_
    done
}

interspace()
{
    echo  $* | sed 's/./& /g'
}

_randstr() {
    [ -z "$1" ] && set -- $upper $lower $digits
    eval "_RANDSTR=\${$(( $RANDOM % $# + 1 ))}"
}

_randword()
{
   rw_len=${1:-8}
   _RANDWORD=
   while [ ${#_RANDWORD} -lt $rw_len ]
   do
     _randstr ${charset:-$upper$lower$digits}
     _RANDWORD=$_RANDWORD$_RANDSTR
   done
}

randword()
{
    _randword "$@" && printf "%s\n" "$_RANDWORD"
}

_rand_word()
{
    [ -z "$fmt" ] && charset=$format _randword ${1:-8}
    rp_fmt=${fmt:-$_RANDWORD}
    _RAND_WORD=
    set -f
    while [ ${#rp_fmt} -gt 0 ]
    do
      rp_=${rp_fmt#?}
      rp_char=${rp_fmt%"$rp_"}
      case $rp_char in
          c) _randstr $consonants ;;
          d) _randstr $digits ;;
          f) _randstr $format ;;
          l) _randstr $lower ;;
          p) _randstr $punct ;;
          u) _randstr $upper ;;
          v) _randstr $vowels ;;
          C) _randstr $CONSONANTS ;;
          V) _randstr $VOWELS ;;
          \\) rp_fmt=$rp_
              rp_=${rp_fmt#?}
              rp_char=${rp_fmt%"$rp_"}
             _RANDSTR=$rp_char
             ;;
          *) _RANDSTR=${rp_fmt%"$rp_"}
              ;;
      esac
      _RAND_WORD=$_RAND_WORD$_RANDSTR
      rp_fmt=$rp_
    done
set +f
}

rand_word()
{
    _rand_word "$@" && printf "%s\n" "$_RAND_WORD"
}

lower='a b c d e f g h i j k l m n o p q r s t u v w x y z '
upper='A B C D E F G H I J K L M N O P Q R S T U V W X Y Z '
digits='0 1 2 3 4 5 6 7 8 9 '
punct='% # ! @ ? > } | \ = - _ ) ( + * & ^ $ <'
format='u l d u l p '

## these are just for fun
vowels='a e i o u '
consonants='b c d f g h j k l m n p q r s t v w x y z '
VOWELS='A E I O U '
CONSONANTS='B C D F G H J K L M N P Q R S T V W X Y Z '
format='u l d u l p v c V C '

fmt=
num=1
length=
len_lower=6
len_upper=8
charset=$lower_$upper_$digits_$punct

opts=n:f:F:l:a:

while getopts "$opts" opt
do
  case $opt in
      a) case $OPTARG in   ## list of characters allowed
            *[!\ \	][!\ \	]*) format=`interspace $OPTARG` ;;
            *) format=$OPTARG ;;
         esac
         ;;
      l) len_lower=${OPTARG%[!0-9]*}     ## -l LL,UU  lower and upper no. of chars
         case $len_lower in *[!0-9]*) exit 5 ;; esac
         len_upper=${OPTARG#*[!0-9]}
         case $len_upper in *[!0-9]*) exit 5 ;; esac
         [ $len_lower -gt $len_upper ] && {
             len_lower=$len_upper
             len_upper=${OPTARG%[!0-9]*}
         }
         ;;
      n) case $OPTARG in *[!0-9]*) exit 5 ;; esac  ## number of passwords to generate
         num=$OPTARG ;;
      f) fmt=$OPTARG ;; ## format string .e.g -f ucClvVdpp (see _rand_word() for meanings)
      F) case $OPTARG in *[!0-9]*) exit 5 ;; esac
         charset=$format _randword $OPTARG   ## all passwords use same format string
         fmt=$_RANDWORD
         ;;
  esac
done

while [ $num -gt 0 ]
do
  [ $len_upper = $len_lower ] && length=$len_upper ||
         length=$(( $RANDOM % ($len_upper - $len_lower) + $len_lower ))
  rand_word $length
  num=$(( $num - 1 ))
done