cpp / latest / filesystem / space_info.html /

std::filesystem::space_info

Defined in header <filesystem>
struct space_info {
    std::uintmax_t capacity;
    std::uintmax_t free; 
    std::uintmax_t available; 
};
(since C++17)

Represents the filesystem information as determined by filesystem::space.

Member objects

capacity
total size of the filesystem, in bytes
(public member object)
free
free space on the filesystem, in bytes
(public member object)
available
free space available to a non-privileged process (may be equal or less than free)
(public member object)

Non-member functions

operator==
(C++20)
compares two space_infos
(function)

operator==(std::filesystem::space_info)

friend bool operator==( const space_info&, const space_info& ) = default;
(since C++20)

Checks if capacity, free and available of both arguments are equal respectively.

This function is not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::filesystem::space_info is an associated class of the arguments.

The != operator is synthesized from operator==.

Example

#include <iostream>
#include <filesystem>
#include <cstdint>
 
void print_space_info(auto const& dirs, int width = 14)
{
    std::cout << std::left;
    for (const auto s : {"Capacity", "Free", "Available", "Dir"})
        std::cout << "│ " << std::setw(width) << s << ' ';
    std::cout << '\n';
    std::error_code ec;
    for (auto const& dir : dirs) {
        const std::filesystem::space_info si = std::filesystem::space(dir, ec);
        std::cout
            << "│ " << std::setw(width) << static_cast<std::intmax_t>(si.capacity) << ' '
            << "│ " << std::setw(width) << static_cast<std::intmax_t>(si.free) << ' '
            << "│ " << std::setw(width) << static_cast<std::intmax_t>(si.available) << ' '
            << "│ " << dir << '\n';
    }
}
 
int main()
{
    const auto dirs = { "/dev/null", "/tmp", "/home", "/null" };
    print_space_info(dirs);
}

Possible output:

│ Capacity       │ Free           │ Available      │ Dir
│ 8342851584     │ 8342851584     │ 8342851584     │ /dev/null
│ 12884901888    │ 3045265408     │ 3045265408     │ /tmp
│ 250321567744   │ 37623181312    │ 25152159744    │ /home
│ -1             │ -1             │ -1             │ /null

See also

(C++17)
determines available free space on the file system
(function)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/filesystem/space_info