如何以编程方式获取 Linux 中挂载点的源设备?

How to get source device of mount point in Linux programmatically?

我想知道某个目录挂载了哪个设备,像这样:

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

这是一个起点,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";