What does dead beef mean?

Question

What does the word dead beef mean? I read it from an interview. It has something to do with ipv6. I figured it might be a random hexadecimal number used for examples, for example, "A quick brown fox jumps over a lazy dog."

Do I understand correctly? Or does that make more sense?

Answer 1

http://en.wikipedia.org/wiki/Hexspeak
http://www.urbandictionary.com/define.php?term=dead%3Abeef

"Dead beef" is a very popular programming suggestion because it is built only from the letters af, which are used in hexadecimal notation. The columns at the beginning and middle of the sentence make this sentence (theoretically) a valid IPv6 address.

Answer 2

This is a pronounced expression that uses only the letters AF, often used when a recognizable hexadecimal number is required. Some systems use it for various purposes, such as displaying memory that has been freed up and should not be mentioned again. In the debugger, this value may be a sign that you made a mistake. From Wikipedia :

0xDEADBEEF ("dead beef") is used by IBM RS / 6000, Mac OS on 32-bit PowerPC processors and Commodore Amiga as a magic debug value. At Solaris Solar Microsystems, it notes freed kernel memory. In OpenVMS running on Alpha processors, DEAD_BEEF can be seen by pressing CTRL-T.

The number 0xDEADBEEF equals the less recognizable decimal number 3735928559 (unsigned) or -559038737 (signed).

Answer 3

The value 0xDEADBEEF has three practical advantages, mainly for older systems. The old assembler / C-hacks, like me, would use it to fill unallocated memory in order to resolve memory problems. In addition, it is a pun of the slang term "dead meat". A programmer is dead meat if DEADBEEF terminates in its pointers. I congratulate the guy who first thought about using the DEADBEEF value. This is smart in many ways.

As for practical reasons, firstly, it is more noticeable in a dump with a hexadecimal memory, because in fact it pronounces words in contrast to random hexadecimal values.

Secondly, if the value is delayed in the pointer, it is likely to cause a memory error out of range. The DEADBEEF address is out of the range of system addresses (we are talking about systems of the last century) regardless of the system endian.

Thirdly, it is more likely to cause an error in systems for which even boundary pointer values ​​are required to access 16/32/64-bit data. The value has a high probability of error, since both of the 16-bit values ​​(DEAD, BEEF) are odd.

Answer 4

It is also used for debugging purposes.

Here is a handy list of some of these values:

http://en.wikipedia.org/wiki/Magic_number_%28programming%29#Magic_debug_values

Answer 5

Since IPv6 Addresses are written in Hex notation, you can use "Hexspeak" (numbers 0-9 and letters af) in the addresses.

There are a few words that you can use as valid addresses to better moderate them.

If you ping6 www.facebook.com -n , you will get something like "2a03: 2880: f01c: 601: face: b00c : 0: 1".

Here are some examples:

• : affe :: (Affe - German for Monkey - considered in vlan for rule)
• : 1bad: babe :: (one bad baby - spotted in smtp-honeypot)
• : badc: ab1e :: (bad cable - considered as a subnet for an insecure vlan)
• : da7a :: (Data - for file servers)

Answer 6

Usually people use it to indicate dummy values. I think it was primarily used before the idea of ​​NULL pointers.

Answer 7

This is a magic number used in different places because it can also be read in English, which makes it outstanding. There is an incomplete list on Wikipedia .

Answer 8

It was used as a template for storing in memory as a series of hexadecimal bytes (0xde, 0xad, 0xbe, 0xef). You could see if the memory is corrupted due to a hardware failure, buffer overflow, etc.

Answer 9

0xDEADBEEF is usually filled with memory arrays, so any exception if it is incorrectly specified or know the buffer for runs, etc.,