+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <string.h>
+#include "test.h"
+
+#define TEST(c, ...) ( (c) || (t_error(#c " failed: " __VA_ARGS__),0) )
+
+static int w(pid_t pid)
+{
+ int r, s;
+ r = waitpid(pid, &s, 0);
+ if (r == -1)
+ t_error("waitpid failed: %s\n", strerror(errno));
+ else if (r != pid)
+ t_error("child pid was %d, waitpid returned %d\n", pid, r);
+ else
+ return s;
+ return -1;
+}
+
+static void test_exit(int code)
+{
+ pid_t pid;
+ if((pid = vfork()) == 0) {
+ _exit(code);
+ t_error("exit failed: %s\n", strerror(errno));
+ }
+ if (pid == -1) {
+ t_error("vfork failed: %s\n", strerror(errno));
+ return;
+ }
+ int r = w(pid);
+ TEST(WIFEXITED(r), "child terminated abnormally\n");
+ TEST(WEXITSTATUS(r) == code, "child exited with %d, expected %d\n", WEXITSTATUS(r), code);
+}
+
+static void test_kill(int sig)
+{
+ pid_t pid;
+ if((pid = vfork()) == 0) {
+ raise(sig);
+ t_error("raise failed: %s\n", strerror(errno));
+ }
+ if (pid == -1) {
+ t_error("vfork failed: %s\n", strerror(errno));
+ return;
+ }
+ int r = w(pid);
+ TEST(WIFSIGNALED(r), "child did not get killed\n");
+ TEST(WTERMSIG(r) == sig, "child is killed by %d, expected %d\n", WTERMSIG(r), sig);
+}
+
+static int sh(const char *cmd)
+{
+ pid_t pid;
+ if((pid = vfork()) == 0) {
+ execl("/bin/sh", "/bin/sh", "-c", cmd, (char*)0);
+ t_error("execl failed: %s\n", strerror(errno));
+ _exit(1);
+ }
+ if (pid == -1) {
+ t_error("vfork failed: %s\n", strerror(errno));
+ return -1;
+ }
+ return w(pid);
+}
+
+static void test_shell_exit(const char *cmd, int code)
+{
+ int r = sh(cmd);
+ TEST(WIFEXITED(r), "child terminated abnormally\n");
+ TEST(WEXITSTATUS(r) == code, "child exited with %d, expected %d\n", WEXITSTATUS(r), code);
+}
+
+static void test_shell_kill(const char *cmd, int sig)
+{
+ int r = sh(cmd);
+ TEST(WIFSIGNALED(r), "child did not get killed\n");
+ TEST(WTERMSIG(r) == sig, "child is killed by %d, expected %d\n", WTERMSIG(r), sig);
+}
+
+int main() {
+ test_exit(0);
+ test_exit(1);
+ test_kill(SIGKILL);
+ test_shell_exit("exit 0", 0);
+ test_shell_exit("exit 1", 1);
+ test_shell_kill("kill -s HUP $$", SIGHUP);
+ return t_status;
+}