Thursday, August 21, 2008


There are only 16 characters to work with, but programmers just love coming up with creative spellings using hex numbers. I suspect that leetspeak evolved out of these spellings, though personally I prefer the original form.

I assume that everyone working as a software developer in English will have seen 0xdeadbeef, and probably some other favorites as well.

deadbeefold standby #1
feedf00dold standby #2
feedfaceold standby #3
decafbaddevelopers love to complain about coffee
badcafedevelopers really love to complain about coffee
badc0ffeedevelopers really, really love to complain about coffee
badc0c0aMacOS X developers might find more meaning in this one.
c0c0abadPeople who hate MacOS X developers might find more meaning in this one.

A little sed scripting on /usr/share/dist/words can turn up a lot of interesting combinations. For the edification and bemusement of the Gentle Reader, allow me to present a few of them here. I rejected most of the results where '5' replaced an 'S' as being too ugly, but a few passed muster.

cat /usr/share/dict/words | sed \
    -e "s/nine/9/g" -e "s/eight/8/g" -e "s/seven/7/g" -e "s/six/6/g"   \
    -e "s/five/5/g" -e "s/four/4/g" -e "s/three/3/g" -e "s/two/2/g"    \
    -e "s/one/1/g"  -e "s/zero/0/g"                                    \
    -e "s/ated/8ed/g"  -e "s/[oO]/0/g" -e "s/[lL]/1/g" -e "s/[sS]/5/g" \
    | egrep -v "[^0123456789aAbBcCdDeEfF]"

The first few seem particularly suitable for memory fenceposts, either guard words before and after allocations or patterns to scribble over freed memory when looking for use-after-free bugs.

a110c8edThis memory is in use, buster!
5eef3712This is ~(0xa110c8ed). No, it doesn't spell anything nifty.
dea110c8Scribble over memory after free(), to catch dangling references.
defec8edto crap all over memory
defacedanother bit pattern to scribble over memory to catch use-after-free errors

To express one's true feelings about the quality of the code base there are really only two options:

  1. Profanity-laden comment blocks
  2. Clever use of constants
c0defadedIt is a well known fact that old code suffers bit rot. Refactor often!
badfacadeThere are times when bad code can only be papered over. This is one of those times.
effaceGood code doesn't make a spectacle of itself.
defaceBad code, on the other hand, gets drunk at its best friends wedding and hits on the bride.
decadeThis code base has been under development for a long time.
baddeedThe EULA for this product specifies the precise amount of bad karma accumulated by using it.
accededThe software has finally given in.
befa11As in "what has befallen yon dead process?"
c0dedbadself explanatory

Magic numbers are useful in all sorts of situations. Encoding one's birthday (0xMMDDYYYY) is clever, but obscure. Subtle jokes in hex also work well.

abbacadabbaUnfortunately 44 bits won't magically fit into a uint32_t.
Said the monkey to the chimp. Real magic numbers are 128 bit.
d00beeDebugging probably qualifies as "medicinal purposes."
d0dec0deHow does one pronounce ioctl anyway? "eye oh cottle," or "eye oct all ?"
babe2bedThe kid's bedtime is 7pm sharp.
b0cceba11You know, I only discovered Bocce Ball in my 30s.
5ca1ab1eIgnore what you see elsewhere, the secret to scalability is in using good magic numbers.
0x1deWith the leading 0x it sortof looks like "oxide" ... I admit it, this one sucks.

Why should return codes be boring? {0, 1, 2, ...} is so dull. We can do better.

fa1afe1even more yummy!
b1abbedprobably I/O related
beddedThe code went to sleep?
b0bbedThey call it "floating point" for a reason, bub.
beadedUm, yeah. I can't think of anything funny about this one.
bab00My sweet baboo!
10adedI bet it has an itchy trigger finger, too.
ba11adI structure all my code to iambic pentameter.
a100fMy code doesn't like me.
acc01adeProgrammers rarely, if ever, hear praise of their work.
affab1eRelatively approachable and friendly code, I guess.
babb1eWhy yes, my functions tend to be a bit on the longish side. Why?
baff1eWhy yes, my functions tend to be a bit on the complex side. Why?
babe1You can write FORTRAN in any language.
ba1b0aIts the Eye of the Tiger, baby!
ed1f1celarge, imposing blocks of code
5ecededThis module has declared its independence from the rest of the system.
5c01dedAt times, it is necessary to be stern with the codebase. Give it a time out.
5caff01dThis code was intended to be temporary. That was four years ago. Such is the way of things.
ad0beI bet they use this one in Photoshop.
ab0demy humble abode
d8edbabeIn college, yeah, sure you did.
0ddba11That is a strange one, alright.

Finally, here are some 16 bit numbers which are more interesting than "dead," "f00d" and "beef"

cacaA statement about software quality, I suppose.
deafWhen programming, no-one can hear you scream.
c0edIt is the 21st century, after all.
ba1dIf tires can go bald, why not programs?
a1faI couldn't find a reasonable approximation of beta.
f01dOrigami programming!
fa11If code falls in the forest, does it make a sound?
c01dSoftware is a dish best served cold.
ab1eOr ! 0xab1e, as the case may be.
cedeI give up, I'm done.

Do you have any additional hex numbers to share? The comments section is open for business.

Update: Lisa Simone wrote an article about teaching embedded systems and the use of hex words in an article on her site.