1 #include <errno.h>
2 #include <string.h>
3 #include <stdlib.h>
4 #include <stdio.h>
5 #include <unistd.h>
6 #include <sys/types.h>
7 #include <sys/wait.h>
8
9 #ifdef __FreeBSD__
10 #include <sys/procdesc.h>
11 #endif
12
13 #ifdef __linux__
14 #include <sys/syscall.h>
pdfork(int * fd,int flags)15 int pdfork(int *fd, int flags) {
16 return syscall(__NR_pdfork, fd, flags);
17 }
18 #endif
19
main()20 int main() {
21 int procfd;
22 int rc = pdfork(&procfd, 0);
23 if (rc < 0) {
24 fprintf(stderr, "pdfork() failed rc=%d errno=%d %s\n", rc, errno, strerror(errno));
25 exit(1);
26 }
27 if (rc == 0) { // Child process
28 sleep(1);
29 exit(123);
30 }
31 fprintf(stderr, "pdfork()ed child pid=%ld procfd=%d\n", (long)rc, procfd);
32 sleep(2); // Allow child to complete
33 pid_t child = waitpid(-1, &rc, WNOHANG);
34 if (child == 0) {
35 fprintf(stderr, "waitpid(): no completed child found\n");
36 } else if (child < 0) {
37 fprintf(stderr, "waitpid(): failed errno=%d %s\n", errno, strerror(errno));
38 } else {
39 fprintf(stderr, "waitpid(): found completed child %ld\n", (long)child);
40 }
41 return 0;
42 }
43