unix « macro « C Q&A

1. Properly handling platform specifics (unix/windows) in C?    stackoverflow.com

This question is intentionally very generic and I'm not much of a C programmer although I dabble here and there. The following code is intentionally vague and probably won't compile, ...

2. C, Unix Domain Sockets, Ancillary data, and GCC; Using CMSG_DATA macro    stackoverflow.com

How can I do this:

*(int *)CMSG_DATA(hdr) = fd2pass;

error: dereferencing type-punned pointer will break strict-aliasing rules

-Wall -Werror -pedantic

3. Trouble with S_ISXXX(m) macros from sys/stat.h    stackoverflow.com

I'm having trouble with S_ISXXX(m) macros from sys/stat.h Specifically almost everything is reported as directory. Only regular files are correctly reported as regular files, links, devices, fifos, all seem to be reported ...