Hacker News Reader

Comment by ComputerGuru | Hacker News Reader

C# is my second-favorite language. I made a shebang to do the same for rust (my number one) many years ago with zero (external) dependencies: https://neosmart.net/blog/self-compiling-rust-code/

View on HN

Seems a little complicated when you can do:

  //usr/bin/env rustc "$0" && ./config "$@"; exit

  //usr/bin/env rustc --edition 2024 "$0" && ./$(basename $0 .rs); rm $(basename $0 .rs); exit

&& in a shebang isn't portable, having more than one argument in a shebang isn't portable, subshell in a shebang isn't portable, semicolon in a shebang isn't portable, basename usage isn't portable, not littering the current working directory is important (it might not even be RW, or you might not have permissions to write to it), your usage won't work with symlinks or with the script added to $PATH, caching the compiled output is a nice speedup and reduces startup costs, correct (and optimal) cache invalidation is one of the known tricky problems in CS.

Shell scripts are ugly :)

(If you didn't mean to use them in a shebang but rather as the script body, that's fine but that wouldn't be possible without the polyglot syntax and #allow abuse I posted.)

Thanks, I looked it up and it's indeed quite ugly, and my shebang isn't portable. A little saddened that even 'env -S' didn't make it to POSIX.

No worries and believe me, I feel your pain (I moonlight as a (fish-)shell dev).

I would have liked to use `exec -a` to set the executable name (as mentioned in the comments on the article) but alas, that too is not portable.

Reply on news.ycombinator.com