| Standards / Extensions | C or C++ | Dependencies |
|---|---|---|
POSIX.1 |
both |
#define _POSIX_SOURCE
#include <unistd.h>
pid_t getpgrp(void);Finds the process group ID of the calling process.
Returns the found value. It is always successful.
There are no documented errno values.
⁄* CELEBG13
This example gets all the process group IDs.
*⁄
#define _POSIX_SOURCE
#include <unistd.h>
#include <sys⁄wait.h>
main() {
int status;
if (fork() == 0) {
if (fork() == 0) {
printf("grandchild's pid is %d, process group id is %d\n",
(int) getpid(), (int) getpgrp());
exit(0);
}
printf("child's pid is %d, process group id is %d\n",
(int) getpid(), (int) getpgrp());
wait(&status);
exit(0);
}
printf("parent's pid is %d, process group id is %d\n",
(int) getpid(), (int) getpgrp());
printf("the parent's parent's pid is %d\n", (int) getppid());
wait(&status);
}parent's pid is 5373959, process group id is 5111816
the parent's parent's pid is 5111816
child's pid is 5832710, process group id is 5111816
grandchild's pid is 196617, process group id is 5111816