#!/usr/bin/ksh93
################################################################
function usagemsg {
  print ""
  print "Program: mkstring"
  print ""
  print "This script generates a random string of characters"
  print ""
  print "Usage: ${1##*/} [-?] [-v] [-V] [-m minimum] [-x maximum]"
  print ""
  print "    Where '-m minimum' = Specify the minimum number of characters"
  print "                 to be returned in the random string (Default:10)"
  print "          '-x maximum' = Specify the maximum number of characters"
  print "                 to be returned in the random string (Default:10)"
  print "          '-l' = Only return lower case characters in random string"
  print "          '-u' = Only return upper case characters in random string"
  print "          '-v' = Verbose mode"
  print "          '-V' = Very Verbose Mode"
  print ""
  print "Author: Dana French (dfrench@mtxia.com)"
  print ""
  print "\"AutoContent\" enabled"
  print ""
}
################################################################
################################################################
TRUE="1"
FALSE="0"
CHARS=( a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z )
CNUM="52"
VERBOSE="${FALSE}"
VERYVERB="${FALSE}"
MIN="10"
MAX="${MIN}"

while getopts ":vVulm:x:" OPTION
do
    case "${OPTION}" in
        'v') VERBOSE="${TRUE}";;
        'V') VERYVERB="${TRUE}";;
        'm') MIN="${OPTARG}";;
        'x') MAX="${OPTARG}";;
        'u') typeset -u CHARS;;
        'l') typeset -l CHARS;;
        '?') usagemsg "${0}" && exit 1 ;;
    esac
done
 
shift $(( ${OPTIND} - 1 ))

trap "usagemsg ${0}" EXIT
if (( MAX < MIN ))
then
  print -u 2 "ERROR: run \"${0} -?\" for help and usage}"
  exit 1
fi
trap "-" EXIT

(( VERYVERB == TRUE )) && set -x

################################################################

(( MAX != MIN )) && (( MAX++ ))
(( MIN == MAX )) &&
  MAXLEN=${MIN} ||
  MAXLEN=$(( MIN + ( RANDOM % ( MAX - MIN ) ) ))

for (( i=0; i < MAXLEN; ++i ))
do
    STRING="${STRING}${CHARS[${RANDOM}%${CNUM}]}"
done
print ${STRING}