#!/bin/bash
a=0
function write {
        echo $a >> part1script.txt
}

function read {
        if [ ! -s part1script.txt ]
                then (( a += 1 ))
        else
                a=` tail -n 1 part1script.txt `
                (( a += 1 ))
        fi
}

function lock {
#        while [ -e part1script.lock ]
#        do
#                sleep 5
#        done

#        echo 0 > part1script.lock
        read
        write
#        rm part1script.lock
}

for i in $(seq 1 1000)
do
        lock
done

echo 'done'