Trying to understand a Bash script given to me, specifically the while loop : <p>I am using a script made by one of my former colleagues, he told me I'll need some working with it. I am wondering what this while loop does:</p>

<pre><code># This is the loop that does the simulation
lastsim=0
nextsim=`/usr/bin/expr $lastsim + 1`

while [ $nextsim -le $upperlimit ]
do

  cp -i Dynamics_${lastsim}_500ps/*.prmtop ./$paramInput.prmtop
</code></pre>

<p>specifically I'm confused by thie -le syntax
This is only part of the script I can upload the rest if necessary.</p>
