include/wait.h

   1 /* Define how to access the int that the wait system call stores.
   2    This has been compatible in all Unix systems since time immemorial,
   3    but various well-meaning people have defined various different
   4    words for the same old bits in the same old int (sometimes claimed
   5    to be a struct).  We just know it's an int and we use these macros
   6    to access the bits.  */
   7
   8 /* The following macros are defined equivalently to their definitions
   9    in POSIX.1.  We fail to define WNOHANG and WUNTRACED, which POSIX.1
  10    <sys/wait.h> defines, since our code does not use waitpid().  We
  11    also fail to declare wait() and waitpid().  */
  12
  13 #define WIFEXITED(w)    (((w)&0377) == 0)
  14 #define WIFSIGNALED(w)  (((w)&0377) != 0177 && ((w)&~0377) == 0)
  15 #define WIFSTOPPED(w)   (((w)&0377) == 0177)
  16
  17 #define WEXITSTATUS(w)  ((w) >> 8)      /* same as WRETCODE */
  18 #define WTERMSIG(w)     ((w) & 0177)
  19 #define WSTOPSIG(w)     ((w) >> 8)
  20
  21 /* These are not defined in POSIX, but are used by our programs.  */
  22
  23 #define WAITTYPE        int
  24
  25 #define WCOREDUMP(w)    (((w)&0200) != 0)
  26 #define WSETEXIT(w,status) ((w) = (0 | ((status) << 8)))
  27 #define WSETSTOP(w,sig)    ((w) = (0177 | ((sig) << 8)))