- #1
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from programming long ago?
Do you remember DEADBEEF from your early programming days?
- Thread starter jim mcnamara
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SUMMARY
The hexadecimal number 0xDEADBEEF, representing the decimal value 3735928559, is commonly used in programming as a recognizable sentinel value or marker for null data in memory. It serves as a default setting in various applications and is often referenced in hexadecimal jokes and discussions. Other similar values include 0xFEEDBEEF and 0xDEAFBEEF, which are utilized for debugging and memory management in systems like Solaris. The discussion highlights the cultural significance of these values among programmers and their historical context in software development.
PREREQUISITES- Understanding of hexadecimal notation and its applications in programming
- Familiarity with memory management concepts, particularly in C/C++
- Knowledge of debugging techniques and the use of magic numbers
- Basic programming experience, especially in languages that utilize pointers and memory allocation
- Research the use of magic numbers in programming and their implications
- Learn about memory management techniques in C/C++, focusing on malloc and free
- Explore the significance of sentinel values in software development
- Investigate other hexadecimal values used in programming and their applications
Programmers, software developers, and computer science students interested in memory management, debugging practices, and the cultural aspects of programming humor.
- #2
Borg
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Yes.
- #3
gmax137
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no.
- #4
Mark44
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Sure. The hex number 0xDEADBEEF happens to be the decimal number 3735928559, although that's of no real consequence.
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Borg
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Maybe it's his phone number. 
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berkeman
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I remember that we used it as a default setting a few years ago (I don't remember the exact application), but it was pointed out that it might not sit well with our vegetarian customers (which we never thought of), so we changed it. Not so much to be PC, but to avoid potential conflicts. (And that was before I married a vegetarian...) 
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Klystron
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I tried to relate a few hexadecimal jokes before but they fell flat. Either jokes made with words formed from the first six letters of the alphabet (combined with digits 0..9 ?) are not funny or people do not program hex any more. Cafe Dead, Feed Beef, Deaf Fade, Aced Deed.
Ho-Hum
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Vanadium 50
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Klystron said:
I agree. Jokes are better in other bases:
Why do programmers confuse Christmas with Halloween?
Because 31 Oct = 25 Dec
- #9
Borek
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Yep.
- #10
DavidSnider
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Yep.
Code:
_ _
((___))
[ x x ]
\ /
(' ')
(U)- #11
diogenesNY
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Wow. This takes me back to the days when 32767 was the highest number in the universe!
I seem to have some recollection that deadbeef was null data on some systems... i.e. if you read some section of a program or data space that contained null data (as opposed to just zeros or random noise), than you would see deadbeef, in hex... but this is just a vague wisp of unrefreshed memory.
diogenesNY
I seem to have some recollection that deadbeef was null data on some systems... i.e. if you read some section of a program or data space that contained null data (as opposed to just zeros or random noise), than you would see deadbeef, in hex... but this is just a vague wisp of unrefreshed memory.
diogenesNY
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Nugatory
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Sure, and there are many more as well. We used these values when we needed something that would stand out in a hex dump (either scanning visually or searching), or a recognizable sentinel valuejim mcnamara said:
A few others: FEEDBEEF, FEEDFACE, DEAFBEEF, ...
- #13
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Solaris' malloc uses it to mark free memory. FWIW.
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DrClaude
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I had to look up DEADBEEF when I first stumbled on this thread and I found the following interesting list:Nugatory said:
https://en.wikipedia.org/wiki/Magic_number_(programming)#Magic_debug_values
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