Is Android POSIX-compatible? I know it uses the Linux kernel, but I'm not sure if that means it's POSIX compatible, as the POSIX standard deals more with userland functions. So, is it compatible?
For example, if I use only ANSI and POSIX functions in my C program, would it compile and run on Android without needing any code-changes?
GNU libc (glibc) is too big and complicated for mobile phones, so Android implements its own special version of libc which is Bionic libc, which itself does not fully support POSIX. One of the most lacking features in the android Bionic libc is pthread_cancel(), so if you don't use it, your code will probably do fine.
And also as @code monkey mentioned you can take a look to the bionic source code. You can find additional information here .