rust_cmd_lib VS axiom

With rust_cmd_lib, you can write below code without launching shell:

zsh is also doing the variable substitution better than bash. FYI, I just released rust_cmd_lib 1.0 recently, which can do variable substitution without any quotes: https://github.com/rust-shell-script/rust_cmd_lib

With cmd_lib and rayon, it could be done in below one line code:

#!/usr/bin/env ngs # In response to https://github.com/rust-shell-script/rust_cmd_lib/blob/1f2fc2303db3f467c42589bd944b31834c8a0bca/examples/dd_test.rs # $ ./dd_test.ngs --file /dev/nvme0n1 --block_size 4096 --threads_count 4 # [LOG 2021-03-20 10:57:14 IST] Dropping caches at first # [LOG 2021-03-20 10:57:14 IST] Running command: sudo bash -c echo\ 3\ \>\ /proc/sys/vm/drop_caches # [LOG 2021-03-20 10:57:15 IST] Running with threads: 4, block size: 4096 # [LOG 2021-03-20 10:57:15 IST] Running command: sudo bash -c dd\ if=/dev/nvme0n1\ of=/dev/null\ bs=4096\ skip=1310720\ count=655360\ 2\>\&1 # [LOG 2021-03-20 10:57:15 IST] Running command: sudo bash -c dd\ if=/dev/nvme0n1\ of=/dev/null\ bs=4096\ skip=655360\ count=655360\ 2\>\&1 # [LOG 2021-03-20 10:57:15 IST] Running command: sudo bash -c dd\ if=/dev/nvme0n1\ of=/dev/null\ bs=4096\ skip=1966080\ count=655360\ 2\>\&1 # [LOG 2021-03-20 10:57:15 IST] Running command: sudo bash -c dd\ if=/dev/nvme0n1\ of=/dev/null\ bs=4096\ skip=0\ count=655360\ 2\>\&1 # [LOG 2021-03-20 10:57:22 IST] thread 0 bandwidth: 450 MB/s # [LOG 2021-03-20 10:57:22 IST] thread 1 bandwidth: 451 MB/s # [LOG 2021-03-20 10:57:22 IST] thread 2 bandwidth: 453 MB/s # [LOG 2021-03-20 10:57:22 IST] thread 3 bandwidth: 451 MB/s # [LOG 2021-03-20 10:57:22 IST] Total bandwidth: 1805 MB/s # Command line arguments automatically fed into main() # Default data size - 10G F main(file:Str, block_size:Int=4096, threads_count:Int=1, data_size:Int=10 * 1024 * 1024 * 1024) { log("Dropping caches at first") $(log: sudo bash -c "echo 3 > /proc/sys/vm/drop_caches") log("Running with threads: ${threads_count}, block size: ${block_size}") # Parallel map: each callback runs in it's own thread cnt = data_size / threads_count / block_size results = threads_count.pmap(F(i) { off = cnt * i `log: sudo bash -c "dd if=$file of=/dev/null bs=$block_size skip=$off count=$cnt 2>&1"` }) total_bandwidth = 0 results.each_idx_val(F(i, output) { # "line:" makes the first line of output as the result of `...` bandwidth = `echo $output | line: awk '/MB/ {print $10}'`.Int() log("thread ${i} bandwidth: ${bandwidth} MB/s") total_bandwidth += bandwidth }) log("Total bandwidth: $total_bandwidth MB/s") } # When running without arguments F main() { # exit() - exit code is 1 unless otherwise specified exit("Usage: ${ARGV0} --file FILE [--block_size BLOCK_SIZE] [--threads_count THREADS_COUNT] [--data_size DATA_SIZE]") }

Thanks for the inspiration from previous posts, and I tried to convert pipes.sh to rust code today. It turned out to be very straightforward with the help of rust_cmd_lib, and your can check both language versions in the project examples directory.

Yes, your concern is correct and that's why I encourage people to use macros by default: https://github.com/rust-shell-script/rust_cmd_lib#security-notes

I'm creating a hobby operating system in Nim (early stages). After an initial attempt[0] I decided to start over[1] and document my journey in building it[2]. The focus for me is on learning low-level systems programming and enjoying the journey, rather than building something production ready.

[0] https://github.com/khaledh/axiom

[1] https://github.com/khaledh/fusion

[2] https://0xc0ffee.netlify.app/osdev/01-intro.html

> kernel developers do not allow third party runtimes in the kernel. Even meager Rust's "panic" runtime is a contentious

Much in Linux is contentious :-) which is why the module system is nice. A kernel module for C code requires no permission from Linux-core unless you need it distributed with the kernel (which, yes, might be required for "credibility" - but critically also might not). It may require many decls to access various kernel APIs, but those can be (semi-)automated or just done as-needed. So, Linux kernel policy is not so relevant (at best) which is what I meant by "no special support" (admittedly brief). Kernel coding is always a bit trickier, and you may need to build up some support code to make integration nice, though as well as decl generators.

> Can one disable runtime in Nim completely -- no GC, no exceptions?

To answer your question, and as discussed elsewhere in this subthread, Nim has many options for memory management.. only stdlib seq/string really needs automatic methods. One can disable the runtime completely via os:standalone and statically check that no exceptions are raised with Nim's effect system (and there are also both setjmp & goto based exception impls which may/may not be workable in Linux/BSD kernel module settings). As "proof more by example", a few people have written OS kernels in Nim recently[1,2] and there was another toy kernel long ago[3].

People have also written OS kernels in Go which "has a GC and runtime".[4] So, I acknowledge it's not quite the same example, but I also see no fundamental blockers for kernel modules.

[1] https://github.com/khaledh/axiom

[2] https://prosepoetrycode.potterpcs.net/2023/01/a-barebones-ke...

[3] https://github.com/dom96/nimkernel

[4] https://github.com/mit-pdos/biscuit/

I gave Rust a few chances, and always came out hating its complexity. I needed a systems programming language to develop a hobby OS[1], and Nim hit the sweet spot of being very ergonomic, optional GC, and great interop with C. I can drop down to assembly any time I want, or write a piece of C code to do something exotic, but the rest of the system is pure Nim. It's also quite fast.

[1] https://github.com/khaledh/axiom

I've used both to work on a hobby OS project (Nim[1], Zig[2]). I very much prefer Nim. Code is succinct, elegant, and lets you focus on your core logic rather than fighting the language.

Zig is nice and I like its optionals support and error handling approach. But I was put off by its noisy syntax, e.g. !?[]u8 to represent an error union of an optional pointer to a many-pointer of uint8. Also having to prepare and weave allocators throughout most of the code that needs to dynamically allocate (which is most of the code) gets in the way of the main logic. Even little things like string concatenation or formatting becomes a chore. Zig also doesn't have dynamic dispatch, which makes polymorphic code hard to write; you have to work around it through some form of duck typing. In the end I realized that Zig is not for me.

[1] https://github.com/khaledh/axiom

Niceness is subjective, but Nim is just as valid an addition to that group. Nim compiles to C and has had an --os=standalone mode for like 10 years from its git history, and as mentioned else-thread (https://news.ycombinator.com/item?id=36506087) can be used for Linux kernel modules. Multiple people have written "stub OSes" in it (https://github.com/dom96/nimkernel & further along https://github.com/khaledh/axiom).

While it can use clang as a backend, Nim does not rely upon LLVM support like Zig or Rust (pre-gcc-rust working). Use on embedded devices is fairly popular: https://forum.nim-lang.org/search?q=embedded (or web search).

Latency-wise, for a time, video game programming was a perceived "adoption niche" or maybe "hook" for Nim and games often have stringent frame rendering deadlines. If you are interested in video games, you might appreciate https://github.com/shish/rosettaboy which covers all but Ada in your list with Nim being fastest (on one CPU/version/compiler/etc). Note, however, that cross-PL comparisons are often done by those with much "porting energy" but limited familiarity with any but a few of the PLs. A better way to view it is that "Nim responds well to optimization effort" (like C/Ada/C++/Rust/Zig).

If anyone is interested, I have a couple of implementations of booting under UEFI and getting a bunch of info about the system (don't expect a functioning system, they just boot and dump some info):

Nim: https://github.com/khaledh/axiom

Zig: https://github.com/khaledh/axiom-zig (this one goes into depth in disassembling ACPI DSDT bytecode)

I wasn't ready to share it yet, but here it goes[1]. It's at a very early stage, but should give you an idea of how to get things up and running under Nim.

I didn't avoid malloc. I provided a simple bump pointer based heap to get things going. Later I'll have to separate things into a UEFI bootloader and a proper kernel image, each with its own allocator (the bootloader will use UEFI memory allocation services, and the kernel will have its own heap).

[1] https://github.com/khaledh/axiom