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Comment by p1mrx | Hacker News Reader

Reminds me of that time I wrote a StringToExecutableFile() function for running [e.g. a Rust binary] from C++, but that depended on several layers of build system horror to embed the executable file as a string, and it wasn't cross-platform.

Imagine a utility function that dumps an embedded string to an unlinked temporary file, sets the +x permission, and returns a /proc/self/fd/N filename so you can exec() a subprocess. It's somewhat difficult because of write^execute limitations in Linux.

Running WASM in process seems like a much saner idea.

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This is of course not the purpose of your post, but since you're interested in this topic, I wanted to mention that you can now create memory-backed files on linux using the memfd_create syscall without using any filesystem (nor unlink) and you can also execute them without the /proc/self/fd trick by using the execveat syscall. In glibc, there is fexecve which uses execveat or falls back to the /proc trick on older kernels.

Looks like memfd_create is from Linux 3.17 (2014), which was after I wrote the function. I sort of miss the days when simple stuff was hard.

>I sort of miss the days when simple stuff was hard.

what? what's the point?

for me it's the most annoying thing when the simple stuff is hard because why would it be?

Hacking is the art doing things with software that don't seem possible.

In other words, it's just fun :)

Imo hacking is different thing

You're entitled to your opinion, of course - language is subjective afterall - but the meaning of the word "hacking" as I'm using it comes from the MIT hacking community as described by Richard Stallman [0] [1].

[0] https://youtu.be/D7PVrK58iGw?t=58

[1] https://stallman.org/articles/on-hacking.html

I agree. I was looking into how you start a child process in C++ recently and I was surprised and not at all surprised to find that the answer is still fork and execve. Ridiculous.

Wouldn't that be OS specific anyway? Like, Windows has no concept of forking processes but instead it uses the CreateProcess function.

Depending on how hacky you can also just re-invent a non-relocating ELF loader

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