title: Is errno thread-safe?
body: <p>In <code>errno.h</code>, this variable is declared as <code>extern int errno;</code> so my question is, is it safe to check <code>errno</code> value after some calls or use perror() in multi-threaded code. Is this a thread safe variable? If not, then whats the alternative ? </p>
  
  <p>I am using linux with gcc on x86 architecture. </p>