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#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <stdlib.h>
int parent_pid;
void parent(pid_t child_pid)
{
int status;
int result;
printf("[parent:%i] wait for child exit\n", parent_pid);
result = waitpid(child_pid, &status, 0);
if (result != child_pid) {
perror("waitpid");
exit(1);
}
printf("[parent:%i] child exited with status %i\n",
parent_pid, status);
}
void child()
{
struct utsname buf;
int err;
int pid = getpid();
printf("[child:%i] uname()\n", pid);
err = uname(&buf);
if (err) {
perror("uname");
exit(1);
}
printf("[child:%i] done, exit.\n", pid);
}
int main()
{
pid_t pid;
/* fork process */
parent_pid = getpid();
printf("[parent:%i] fork\n", parent_pid);
pid = fork();
if (pid < 0) {
perror("fork");
exit(1);
}
if (pid) {
parent(pid);
} else {
child();
}
return 0;
}
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