Add support for macOS and BSD

[factormystic]

Fixes #66. Still doesn't have color in Terminal.app, though.

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This PR was vibe coded with VS Code & Copilot Agent mode. It's fine to close if there's a concurrent effort or something more official. I just wanted to demonstrate it could be done. That said, cargo test passes locally 👍

[factormystic]

@microsoft-github-policy-service agree

[kmarekspartz]

Cross-posting here: #30 (comment)

[lhecker]

You can use libc::__error() instead, I believe. Also, this should be similarly abstracted away:

#[cfg(target_os = "macos")]
pub fn get_errno() -> libc::c_int {
    unsafe { *libc::__error() };
}

#[cfg(not(target_os = "macos"))]
pub fn get_errno() -> libc::c_int {
    unsafe { *libc::__errno_location() };
}

Then you can use it in place of the other calls in this file. This function should go to the end of the file, near the other errno related functions.

[sarvagnan]

This should probably be changed to io::Error::last_os_error() as the cross platform way to do this (sources: https://users.rust-lang.org/t/how-to-get-errno-value-from-rust-libc/85224/9
https://doc.rust-lang.org/std/io/struct.Error.html#method.last_os_error)
Learned about this elsewhere

[lhecker]

This is really nice and also compiles nicely in release mode, but under opt-level=s the last_os_error call doesn't get properly inlined and this leaves quite a lot of code around. I'll see if there's a workaround...

[ProxyCC]

If wanted I can pick this PR up tomorrow if needed and finish the latest requested changes.

[warpdesign]

I confirm this is working with only modifications applied to unix.rs:

Search function doesn't seem to work though:

[lhecker]

@factormystic I pushed a few commits into your PR. It'd be nice if you could check them out.

It'd be really kind if someone could test these latest changes.

[warpdesign]

Works for me (macOS/ARM64). Search function still doesn't work: complains about missing ICU library.

[factormystic]

I pulled your changes and it seems to work fine for me on macOS 👍

[lhecker]

The issue with ICU was also discussed in #52. I've internally requested a Mac for testing this myself, but I don't live in the US so it may be difficult to get one loaned out.

[reynoldskr]

You should be able to link in icu components if you install libicu from brew

[DHowett]

This looks good to me, thanks!

[DHowett]

As a treat, here it is on netbsd