If the exit status value (see Program Termination) of the child
process is zero, then the status value reported by waitpid
or
wait
is also zero. You can test for other kinds of information
encoded in the returned status value using the following macros.
These macros are defined in the header file sys/wait.h.
This macro returns a nonzero value if the child process terminated normally with
exit
or_exit
.
If
WIFEXITED
is true of status, this macro returns the low-order 8 bits of the exit status value from the child process. See Exit Status.
This macro returns a nonzero value if the child process terminated because it received a signal that was not handled. See Signal Handling.
If
WIFSIGNALED
is true of status, this macro returns the signal number of the signal that terminated the child process.
This macro returns a nonzero value if the child process terminated and produced a core dump.