rust_cmd_lib VS rust-playground

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

If you have an object that's !Unpin, then Miri will not apply uniqueness rules to anything containing it [0], including boxes and &mut references. (In the example code, replacing the PhantomPinned with a () will make Miri complain again.) This is considered a temporary (if long-lived) measure to allow async executors to manipulate pinned futures without invalidating all their references and whatnot. Thus, it might be seen as undetected UB, in lieu of a permanent solution.

[0] https://play.rust-lang.org/?version=stable&mode=debug&editio...

That would be true if you used `Vec::clear` too, it doesn't allocate a new vector. My point was that you still end up running Drop implementations with RepeatedField, just not all at once. See https://play.rust-lang.org/?version=stable&mode=debug&editio...

That's a valid Unix path, but rust's quoting does nothing to stop it: https://play.rust-lang.org/?version=stable&mode=debug&editio...

Self-referential structs work fine in Rust and always have.

https://play.rust-lang.org/?version=stable&mode=debug&editio...

The compiler will correctly prevent you from moving the value.

The other way to have a struct that starts out as non-self-referential and then becomes self-referential can be achieved with `unsafe` and `Pin::new_unchecked`, which is how `async {}` is handled.

In rust as currently stands: https://play.rust-lang.org/?version=stable&mode=debug&editio...

On the other hand, both this wrapper and yours are counterproductive if the element size is dynamic (e.g. perhaps you're dealing with some nonsense like:)

    struct ITableColumn {

Overflow checks turn into two's compliments' wrapping, but that's only considered acceptable because bounds checks are not turned off.

https://play.rust-lang.org/?version=stable&mode=release&edit...

I have no idea what you're talking about, but it sounds unnecessarily complicated and why I don't use Rust for any serious work.

This demonstrates the ABA problem in safe Rust: https://play.rust-lang.org/?version=stable&mode=debug&editio...

Substitute the sleep with a combination of doing computation/work and the OS thread scheduler, and you can see how the bug surfaces.

You can also try Rust online using the Rust playground: https://play.rust-lang.org/

(Click ... beside build to get assembly) https://play.rust-lang.org/?version=stable&mode=release&edit...

Unfortunately the go playground doesn't seem to support emitting assembly?