7z e ca-2016.0227-256152.nef.7z -y -o $TMP ca-2016.0227-256152.nef
    7z e ca-2016.0227-256152.nef.7z -y ca-2016.0227-256152.nef.sts
    # Show only md5, not filename. PSR is cmd line s/// w/Perl regexp
    md5sum $TMP/ca-2016.0227-256354.nef | <br>
        psr.pl "s/^(\\w+).*$/\$1/" > freq.tmp
    # Extract original md5 as last w/s token on first line
    head -n1 ca-2016.0227-256354.nef.sts | <br>
        psr.pl "s/^.*\\s+(\\w+)\\s*\$/\$1/"  >> freq.tmp
    # Show frequency distribution, expect 2 copies, same md5, 1 line
    freq.pl freq.tmp  # Hash distinct tokens
    2 ebf5216f8bc9afcd0eb208c4b5a0a18a
    rm $TMP/ca-2016.0227-*.nef ca-2016.0227-256354.nef.sts freq.tmp
    etc. etc. etc...