Smallest self-replicating COM

For the smallest COM, which one you think will be smaller using Assembly language?

1. Use DOS Interrupt to open existing file, create new file, read and write as usual

2. Execute an external program (in this case, run internal "copy" command)

From what I found on the Internet


Is there third option to replicate itself to a new file "4"?

IMHO, using Windows API or linux syscall should be preferred.

Obsolete DOS INT may only applicable on emulator,
which may difficult for justified the "usability",
and not accessible by most of the people.

If someone create an environment with shortcut of command,
and use script to create shorter code,
should this result accepted by others who was using standard shell ?

The smallest entry of each file type wins.

Thanks for your feedback. Yes, I already submitted a Windows EXE as my first entry for this competition, thinking to either submit another program, maybe ELF (Linux) or DOS COM.  But there is not much challenge, because it is open file, create file, read /write, close file, not much improvement can be done to make them shorter. Maybe I don't know how, I am not expert in reverse-engineering.

As for your last question, that will be classified as another file type. And binary.golf website says:
So each file type is different category, standard shell script file is different category than custom shell script file, so I think it is still acceptable.

Will you join, flashang? 

Does sound like everyone is just writing to a new file called "4" from orig or the memory, then outputting "4".

Very "Hello World" exercise, and not as fun as it *could* be.

I *think* I can better the 22 byte .COM file, but I don't have spare cycles these days. Just need to write the memory to disk, and output "4".

Perl quine version, though copying the file version is smaller: (so not entering this one, esp since I adapted from a known Perl quine)

already submitted lua file.

may be do other language when free.

That day I saw this "Uncle Lua" restaurant on the way to nearby town in Cheras. 

(But the photo is from Google Maps, not my own)

Sorry, just kidding.

I submitted another Linux program, 290 bytes for self-replicating file, using syscall 0 (sys_read), 1 (sys_write), 2 (sys_create for file open), 3 (sys_close), 60 (sys_exit) and 85 (sys_creat for creating file).

bat file

bat file

32bit elf binary 171 bytes

It is the same as batch script, relying on external program to do replicating.

32bit elf binary 171 bytes

It is the same as batch script, relying on external program to do replicating.

Wow, nice! Didn't know LYN forum has Linux assembly coder, your binary is indeed 171 bytes and pose a challenge to the 158-byte record set by the security researcher.

I haven't looked into detail, but when I run it in WSL (Ubuntu 22.04.2 LTS), I got this error:


From your arg2, I think must name the program as "a"? A very nice attempt, you should send this entry to BGGP4.

@epud2, I try to find out why the error when I run it, this is the stripped-down version to 118 bytes from yours:



Again, when I run it, it says cannot execute the "a" program (I named it as "a") instead of /bin/bash or /bin/sh:



Strange is it, it tries to execute the current calling program.

Sorry for late respond

I saw two different Python entries:

66 bytes


49 bytes


The latter wins! But please don't send these to BGGP4, because they already submitted them.

at the end, the shortest is "use shell to copy file and echo 4"
and the contest become less meaningful.

it become what @angch said "not as fun as it *could* be."

True, maybe only except HTML:



I think that is very advanced code for average programmer like me. 

for web developer,
familiar with dom, js dynamic create object / action, it is not that hard.

Formed in 2014, Project Zero is a team of security researchers at Google who study zero-day vulnerabilities in the hardware and software systems that are depended upon by users around the world. Our mission is to make the discovery and exploitation of security vulnerabilities more difficult, and to significantly improve the safety and security of the Internet for everyone.

We perform vulnerability research on popular software like mobile operating systems, web browsers, and open source libraries. We use the results from this research to patch serious security vulnerabilities, to improve our understanding of how exploit-based attacks work, and to drive long-term structural improvements to security.

I sent another entry, this time is DLL.....

Dn-FamiTracker-dll-hijack
BGGP4 Submission https://binary.golf/

Produce exactly 1 copy of itself ✅
Name the copy "4" ✅
Not execute the copied file ✅
Print, return, or display the number 4 ✅
Size: 19456 bggp4.dll (pretty big for a dll?)

Dn-FamiTracker v0.5.0.1 contains an undocumented plugins feature.

https://github.com/Dn-Programming-Core-Mana...racker/releases

Step 1. Download and unzip Dn-FamiTracker v0.5.0.1

Step 2. Create a folder called Plugins in the same directory as the exe

Step 3. Place attached DLL in the folder, name it bggp4.dll

Step 4. Launch Dn-Famitracker

Similar to previous years, I didn’t actually submit any of these entries for scoring as I actually help out with scoring other people’s entries with the Binary Golf Association.

Just learn lua for some testing when free.
It's quite easy.

already submitted lua file.

may be do other language when free.

Woohoo, you won the Lua category! 

You're No. 2 in PHP category. Not bad!

And you ranked No. 2 in Python.....  

Yo @binarygolf, here’s my entry 0 for BGGP4 —  a self-replicating UEFI app.

This is the first submission of the collab entry that I’m working on w @netspooky
We’ll be golfing this lil self-rep app so expect smaller and smaller entries to follow.

Entry 0 is a UEFI self-rep app I wrote in nasm-syntax x86 asm (1480 bytes) 
xoxo:

***

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