获取环境变量

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <memory.h>
#include <fcntl.h>
#include <sys/msg.h>
#include <algorithm>


extern char **environ;


inline static std::string print_environ2() noexcept
{

    std::string ret{};

    for (int i = 0; environ[i]; i++)
    {

        ret.append(environ[i]);

        ret.append("\n");
    }

    return ret;

}

void print_environ()
{

    printf("%s \n", print_environ2().c_str());

}