Sort: Fixing opens too many files

[allaboutevemirolive]

Issue #5714 is addressed in this pull request.

Reference:

• RustScan/issues/25
• lychee/issues/1248

The same problem can be found in:

• coreutils/issues/2312
• coreutils/pull/2591

To be honest, I am not sure what the exact solution is to this problem. Increasing ulimit, for example, can resolve this issue, as can removing the -m flag from sort -n -m.

This pull request currently requires the user to run the target bash script in sudo mode. Hopefully, the maintainers can incorporate some hints into this PR.:)

[sylvestre]

sorry but i don't think it is the right approach. Instead, we should investigate where we need to open temporary files and replace it by in memory (or something else) operation

[allaboutevemirolive]

Thank you for your feedback. I'll look at ways to fix the issues without changing system resource limits.

Edit: I think digging into cp.rs can give me some hints, and yes, we need to open temporary files and replace them in memory.

Edit: I have an exam coming up in the first month of 2024. Please feel free to create a new PR and close this one. If no new PR is issued, I will investigate this matter in my spare time. :)