#!/bin/sh
hi=64
lo=1
while [ $[ $hi - $lo ] -gt 1 ] ; do
    mid=$[ ($hi + $lo) / 2 ]
    echo -n "trying $mid MB..."
    if /tmp/alloc $[ $mid * 1024 * 1024 ] ; then
        lo=$mid
        echo "OK"
    else
        hi=$mid
    fi
    echo "$lo $hi $[ $hi - $lo ]"
done
echo $hi MB