/* Copyright (C) 2019
 *
 * This file is part of the osdev components suite
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
 */
#include "utils.h"

// std
#include <libgen.h>
#include <unistd.h>
#include <sstream>

#include <linux/limits.h>

using namespace osdev::components::mqtt;

std::string getPathToBinary(int pid)
{
    static const int sMaxPath = PATH_MAX;
    pid_t p = pid;
    if (-1 == pid)
    {
        p = getpid();
    }
    std::ostringstream oss;
    oss << "/proc/" << p << "/exe";
    char buf[sMaxPath] = { 0 };
    ssize_t r = readlink(oss.str().c_str(), buf, sMaxPath);
    if (-1 == r)
    {
        // "readlink failed"
    }
    if (r >= sMaxPath)
    {
        buf[sMaxPath - 1] = '\0'; // make the buffer 0 terminated
        // "path is too long"
    }
    return dirname(buf);
}