// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT License.

#include "pal_config.h"

#include "getppid.h"

#include <sys/user.h>

#include <sys/param.h>

#if HAVE_SYS_SYSCTL_H

#include <sys/sysctl.h>

#endif

//! @brief GetPPid returns the parent process id for a process

//!

//! GetPPid

//!

//! @param[in] pid

//! @parblock

//! The process id to query for it's parent.

//! @endparblock

//!

//! @retval the parent process id, or UINT_MAX if unsuccessful

//!

pid_t GetPPid(pid_t pid)

{

#if defined(__APPLE__) && defined(__MACH__)

const pid_t PIDUnknown = UINT_MAX;

struct kinfo_proc info;

size_t length = sizeof(struct kinfo_proc);

int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PID, pid};

if (sysctl(mib, 4, &info, &length, NULL, 0) < 0)

return PIDUnknown;

if (length == 0)

return PIDUnknown;

return info.kp_eproc.e_ppid;

#else

return UINT_MAX;

#endif

}