如何以编程方式在 Linux 中获取挂载点的源设备？

Question

我想知道某个目录上挂载了哪个设备，像这样：

auto device = get_device_of_mount_point("/path/to/some/dir");
std::cout << device << std::endl; // /dev/sda1

Answer 1

这里是一个起点，假设 C++17 可用：

#include <string_view>
#include <fstream>
#include <optional>

std::optional<std::string> get_device_of_mount_point(std::string_view path)
{
   std::ifstream mounts{"/proc/mounts"};
   std::string mountPoint;
   std::string device;

   while (mounts >> device >> mountPoint)
   {
      if (mountPoint == path)
      {
         return device;
      }
   }

   return std::nullopt;
}

您可以按如下方式使用此功能。

if (const auto device = get_device_of_mount_point("/"))
   std::cout << *device << "\n";
else
   std::cout << "Not found\n";