getuid

   With POSIX IDs disabled, this function is equivalent to geteuid
   and returns the member number (in OpenVMS terms) from the user
   identification code (UIC).

   With POSIX IDs enabled, returns the real user ID.

   Format

     #include  <unistd.h>

     uid_t getuid  (void);
 

Additional information available:

Description     Return_Value