dd5b6384712fb554bb6e291f2bbcdc9ec2f66554
these functions are specified to fail with EBADF on negative fd arguments. apart from close, they are also specified to fail if the value exceeds OPEN_MAX, but as written it is not clear that this imposes any requirement when OPEN_MAX is not defined, and it's undesirable to impose a dynamic limit (via setrlimit) here since the limit at the time of posix_spawn may be different from the limit at the time of setting up the file actions. this may require revisiting later.
musl libc
musl, pronounced like the word "mussel", is an MIT-licensed
implementation of the standard C library targetting the Linux syscall
API, suitable for use in a wide range of deployment environments. musl
offers efficient static and dynamic linking support, lightweight code
and low runtime overhead, strong fail-safe guarantees under correct
usage, and correctness in the sense of standards conformance and
safety. musl is built on the principle that these goals are best
achieved through simple code that is easy to understand and maintain.
The 1.1 release series for musl features coverage for all interfaces
defined in ISO C99 and POSIX 2008 base, along with a number of
non-standardized interfaces for compatibility with Linux, BSD, and
glibc functionality.
For basic installation instructions, see the included INSTALL file.
Information on full musl-targeted compiler toolchains, system
bootstrapping, and Linux distributions built on musl can be found on
the project website:
http://www.musl-libc.org/