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
|
(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 <cstdint>
#include <filesystem>
#include <iostream>
#include <locale>
std::uintmax_t disk_usage_percent(const std::filesystem::space_info& si,
bool is_privileged = false) noexcept
{
if (constexpr std::uintmax_t X(-1);
si.capacity == 0 || si.free == 0 || si.available == 0 ||
si.capacity == X || si.free == X || si.available == X
)
return 100;
std::uintmax_t unused_space = si.free, capacity = si.capacity;
if (!is_privileged)
{
const std::uintmax_t privileged_only_space = si.free - si.available;
unused_space -= privileged_only_space;
capacity -= privileged_only_space;
}
const std::uintmax_t used_space{capacity - unused_space};
return 100 * used_space / capacity;
}
void print_disk_space_info(auto const& dirs, int width = 14)
{
(std::cout << std::left).imbue(std::locale("en_US.UTF-8"));
for (const auto s : {"Capacity", "Free", "Available", "Use%", "Dir"})
std::cout << "│ " << std::setw(width) << s << ' ';
for (std::cout << '\n'; auto const& dir : dirs)
{
std::error_code ec;
const std::filesystem::space_info si = std::filesystem::space(dir, ec);
for (auto x : {si.capacity, si.free, si.available, disk_usage_percent(si)})
std::cout << "│ " << std::setw(width) << static_cast<std::intmax_t>(x) << ' ';
std::cout << "│ " << dir << '\n';
}
}
int main()
{
const auto dirs = {"/dev/null", "/tmp", "/home", "/proc", "/null"};
print_disk_space_info(dirs);
}
Possible output:
│ Capacity │ Free │ Available │ Use% │ Dir │ 84,417,331,200 │ 42,732,986,368 │ 40,156,028,928 │ 50 │ /dev/null │ 84,417,331,200 │ 42,732,986,368 │ 40,156,028,928 │ 50 │ /tmp │ -1 │ -1 │ -1 │ 100 │ /home │ 0 │ 0 │ 0 │ 100 │ /proc │ -1 │ -1 │ -1 │ 100 │ /null
See also
|
(C++17) | determines available free space on the file system (function) |
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