Decode an exit status

Challenge

wait fills a status word; WEXITSTATUS extracts the child's exit code from it. Reproduce that decoding.

Task

Implement int exit_code(int wstatus) that returns the child's exit code, which lives in bits 8-15 of wstatus.

Input

• wstatus: a wait status word (integer).

Output

The exit code: (wstatus >> 8) & 0xFF.

Example

exit_code(0)        ->   0
exit_code(5 << 8)   ->   5
exit_code(256)      ->   1

Input format

wstatus: a wait status word.

Output format

The exit code in bits 8-15: (wstatus >> 8) & 0xFF.

Constraints

wstatus is an integer status word filled by wait() or waitpid().

Starter code

int exit_code(int wstatus) {
    /* TODO */
    return 0;
}

Common mistakes

Assuming the exit code is in the lowest 8 bits; in standard POSIX wait status, exit code is in bits 8-15.

Edge cases to handle

Exit code 0, exit code 255, exit code 1.