SAMESTR="ThisIsTheSameString" #Same String for uniq 
readonly SAMESTR

##
# Get random integar between 1 and 100
##
function getRandomName(){
    rnd=`expr $RANDOM % 64 + 1`
    return $rnd
}

##
# Get random string, first parametar is length
##
function getRandomString(){
    openssl rand -base64 $1
}

function generate(){
    size=500
    i=0
    while(( $i < $size ))
    do
        getRandomName
        length=$?
        #echo "START"
        if [[ $length -ge 1  && $length -le 25 ]] 
        then
            echo $SAMESTR
        else
            echo `getRandomString $length`
        fi
        let "i++"
    done
}

function sortByASCII(){
    generate | sort | uniq -u
}

function sortByNumeric(){
    generate | sort --numeric-sort | uniq -u
}

echo "Overwrite lines:" > resultASCII #this line should not appear in output file
sortByASCII > resultASCII
echo "Append lines:" >> resultASCII #this line should appear in output file
sortByASCII >> resultASCII

echo "Overwrite lines:" > resultNumeric #this line should not appear in output file
sortByNumeric > resultNumeric
echo "Append lines:" >> resultNumeric #this line should appear in output file
sortByNumeric >> resultNumeric

echo "Number of same string in file:"
generate > randomLines
grep --only-matching $SAMESTR < randomLines | wc --lines