4.4BSD/usr/src/contrib/perl-4.036/atarist/test/tbinmode

open(FP, ">bintest") || die "Can't open bintest for write\n";
binmode FP;
print FP pack("C*", 0xaa, 0x55, 0xaa, 0x55,
                    0xff, 0x0d, 0x0a);
close FP;

open(FP, "<bintest") || die "Can't open bintest for read\n";
binmode FP;
@got = unpack("C*", <FP>);
close FP;
printf "expect:\t7 elements: aa 55 aa 55 ff 0d 0a\n";
printf "got:\t%d elements: %x %x %x %x %x %02x %02x\n", $#got+1-$[, @got;