+/**
+ * Run the given command and wait for it to complete.
+ *
+ * @param file name of the binary to run
+ * @param cmd command line arguments (as given to 'execv')
+ * @return 0 on success, 1 on any error
+ */
+static int
+fork_and_exec (const char *file,
+ char *const cmd[])
+{
+ int status;
+ pid_t pid;
+ pid_t ret;
+
+ pid = fork ();
+ if (-1 == pid)
+ {
+ fprintf (stderr,
+ "fork failed: %s\n",
+ strerror (errno));
+ return 1;
+ }
+ if (0 == pid)
+ {
+ /* we are the child process */
+ /* close stdin/stdout to not cause interference
+ with the helper's main protocol! */
+ (void) close (0);
+ open_dev_null (0, O_RDONLY);
+ (void) close (1);
+ open_dev_null (1, O_WRONLY);
+ (void) execv (file, cmd);
+ /* can only get here on error */
+ fprintf (stderr,
+ "exec `%s' failed: %s\n",
+ file,
+ strerror (errno));
+ _exit (1);
+ }
+ /* keep running waitpid as long as the only error we get is 'EINTR' */
+ while ( (-1 == (ret = waitpid (pid, &status, 0))) &&
+ (errno == EINTR) );
+ if (-1 == ret)
+ {
+ fprintf (stderr,
+ "waitpid failed: %s\n",
+ strerror (errno));
+ return 1;
+ }
+ if (! (WIFEXITED (status) && (0 == WEXITSTATUS (status))))
+ return 1;
+ /* child process completed and returned success, we're happy */
+ return 0;
+}
+