#!/bin/bash
if [ -e part1script.txt ]
        then rm part1script.txt
fi

a=0

function read {
        if [ ! -s part1script.txt ]
                then echo 0 > part1script.txt
        fi

        a = ` tail -n 1 part1script.txt `
        (( a += 1 ))
        write
}

function write {
        echo $a >> part1script.txt
}

while [ $a -lt 10 ]
do
        read
done

echo 'done'