bash scripting help

[lazyboy18]

Im trying to find a "cleaner" way of writing this (lab assignment): 

 

#!/bin/bash

 

if [ "$1" = "" ]; then

        pass() { echo ${1:RANDOM%${#1}:1} $RANDOM; }

{

        pass 'abcdefghijklmnopqrstuvwxyz'

        pass 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

        pass '0123456789'

        pass '@#$%&*+-='

        for i in $( seq 1 $(( 4 + RANDOM % 8 )) )

    do

        pass '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@#$%^&*+-='

    done

}| tee t | sort -R | awk '{printf "%s",$1}'

        echo " is a valid password"

        exit 0

fi

 

This is a program generator and it should validate or generate a password. 

• must be at least 8 characters long but not longer than 16 characters.
• must contain at least 1 digit (0-9).
• must contain at least 1 lowercase letter.
• must contain at least 1 uppercase letter.
• must contain exactly one and only one of @ #  $  %  &  *  +  -  =