title: Good or best way to compile for "POSIX"?
body: <p>I tried to read the "<a href="http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html" rel="nofollow">POSIX standard</a>" that is not very much. If I want to compile "POSIX compatible", is C99 even acceptable or do I have to use flags like <code>gcc -pedantic -Wall -ansi -O3</code> ?</p>