| >Is there a reason that command line tools cannot be re-implemented in Rust and maintain GNU and POSIX compliance? No, there isn't, but what "re-implementations" that I know of don't even try to do that. >If not then the fact that ripgrep is not compliant is irrelevant to the larger point that Rust command line tools could eventually replace existing C command line tools. Of course it's possible. You can go ahead and re-implement them in BASIC even. The point is that it hasn't been done, and until it has been done then such a replacement will not happen. At that point there are further considerations. The C linker is ubiquitous, and remains a strong, underlying presence even on Windows, the one platform where C stands the weakest. The reason that the C linker is so widespread is that while C has no standard ABI, the platforms have very strongly defined ABIs (e.g. systemv abi), and those ABIs are extremely stable and haven't had a single change in over a decade. Those ABIs are also very, very simple and the result is that writing any type of software towards a C library in any language is dead simple. C++ at least has extern "C" going for it, which disables name mangling. Rust doesn't have that, nor does it have a stable ABI. C/C++ are the two most interoperable language out there, with an extremely mature and reliable toolchain. It's simply not justifiable to replace C/C++ with Rust as a systems programming language until this serious problem is fixed. Then furthermore, a vast amount of effort has been put into these tools over the last years to ensure that they run on any *nix and any architecture, and even so they can be ported with relative ease. For example, how do you suggest implementing glibc in Rust? You might argue "why would we need the C standard library when we're porting things to Rust", and the answer is that if you want to make a move towards rust, having a C library (particularly the GNU one, a lot of software depends on GNU extensions) is of utmost importance until that goal has been achieved. |
> C++ at least has extern "C" going for it, which disables name mangling. Rust doesn't have that, nor does it have a stable ABI.
Rust has #[no_mangle] and extern "C" and those two guarantee that ABI stability you're looking for.
> Then furthermore, a vast amount of effort has been put into these tools over the last years to ensure that they run on any *nix and any architecture, and even so they can be ported with relative ease.
That's actually a breeze in Rust, including cross-compilation (which is relatively painful in C/C++).
> For example, how do you suggest implementing glibc in Rust? You might argue "why would we need the C standard library when we're porting things to Rust", and the answer is that if you want to make a move towards rust, having a C library (particularly the GNU one, a lot of software depends on GNU extensions) is of utmost importance until that goal has been achieved.
There's work towards that: https://gitlab.redox-os.org/redox-os/relibc