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

// Licensed under the MIT License.

#include "pal.h"

#include "pal_config.h"

#include "getfileowner.h"

#include "getpwuid.h"

#include "getuserfrompid.h"

#include <string>

#include <sstream>

#include <errno.h>

#if HAVE_SYS_SYSCTL_H

#include <sys/sysctl.h>

#endif

char* GetUserFromPid(pid_t pid)

{

#if defined(__linux__)

// Get effective owner of pid from procfs

std::stringstream ss;

ss << "/proc/" << pid;

std::string path;

ss >> path;

return GetFileOwner(path.c_str());

#elif defined(__APPLE__) && defined(__MACH__)

// Get effective owner of pid from sysctl

struct kinfo_proc oldp;

size_t oldlenp = sizeof(oldp);

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

u_int namelen = sizeof(name)/sizeof(int);

// Read-only query

int ret = sysctl(name, namelen, &oldp, &oldlenp, NULL, 0);

if (ret != 0 || oldlenp == 0)

{

return NULL;

}

return GetPwUid(oldp.kp_eproc.e_ucred.cr_uid);

#else

return NULL;

#endif

}