Run shell command and get PID created process - c++

Question

I have this code which runs the command I give to it:
pid_t Utils::RunCommand(std::string cmd, int * infp, int * outfp)
{
std::cout << cmd << std::endl;
const char* command = cmd.c_str();
int p_stdin[2];
int p_stdout[2];
pid_t pid;
if (pipe(p_stdin) == -1)
return -1;
if (pipe(p_stdout) == -1) {
close(p_stdin[0]);
close(p_stdin[1]);
return -1;
}
pid = fork();
if (pid < 0) {
close(p_stdin[0]);
close(p_stdin[1]);
close(p_stdout[0]);
close(p_stdout[1]);
return pid;
}
else if (pid == 0) {
close(p_stdin[1]);
dup2(p_stdin[0], 0);
close(p_stdout[0]);
dup2(p_stdout[1], 1);
dup2(::open("/dev/null", O_RDONLY), 2);
/// Close all other descriptors for the safety sake.
for (int i = 3; i < 4096; ++i)
::close(i);
setsid();
execl("/bin/sh", "sh", "-c", command, NULL);
_exit(1);
}
close(p_stdin[0]);
close(p_stdout[1]);
if (infp == NULL) {
close(p_stdin[1]);
}
else {
*infp = p_stdin[1];
}
if (outfp == NULL) {
close(p_stdout[0]);
}
else {
*outfp = p_stdout[0];
}
return pid; }
The problem I am having with this code is the returned process ID is for the shell process that runs my command which prevents me from checking if the command I ran is still running. How can I either modify this function to instead return to me the created process or find the child's PID from the parent PID?