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Comment by tvon | Hacker News Reader

For the uninitiated, these are libc libraries for embedded systems (alternatives to glibc).

http://www.uclibc.org/about.html

I wouldn't say that musl is particularly aimed at embedded stuff, simply that its small enough to fit most times. It is a full featured, fast C library.

Indeed, musl is more about correctness/standards compliance and robustness than targeting any specific platforms (provided it's Linux).

Well there are some non Linux ports too now - Midipix for Windows, and some bare metal implementations.

Its also useful for creating statically linked executables, which is usually not possible with glibc if you use certain functions (getaddrinfo?).

I always thought you could statically link glibc - but your executable will be huge as it needs to pull in the entire plus extras.

Regardless - I'm glad I'm not the only one who is concerned about binary sizes.

IME you can statically link glibc, but your statically linked binary will still call ld.so.

The NSS stuff? And something else?

There's some specific things that are supposed to be modular library-wise.

I think you usually get a warning at link-time if you try to statically link GCC and use a function that requires matching libc version at runtime, getaddrinfo was the one I remembered but there are certainly more functions like that:

  x.c:(.text+0x85): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

> I wouldn't say that musl is particularly aimed at embedded stuff, simply that its small enough to fit most times.

Maybe it's not particularly aimed at embedded stuff, but it sure does fit well. I've used it in 3 embedded projects recently, with great results.

The only issue I've run into when trying to use musl is there are a lot of softwares out there that expect glibc, and refuse to run without (even though it probably would work). The Oracle JDK/JRE for ARM is an example, you must compile the OpenJDK from scratch to get it to use musl.

Otherwise, it's a fantastic libc. It's fast to compile, it's tiny in size, and is feature-complete enough for most of my purposes.

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