std::filesy...perm_options(3)

✨ NAME ✨

std::filesystem::perm_options — okay bestie, this is the std::filesy...perm_options(3) page from the C++ Standard Libary manual, and it is literally all about the std::filesystem::perm_options type. 💅

🌸 Synopsis 🌸

Defined in header <filesystem> 🎀

          enum class perm_options {

              replace = /* unspecified */,
              add = /* unspecified */,      (since C++17)
              remove = /* unspecified */,
              nofollow = /* unspecified */

          };

This type represents available options that control the behavior of the function std::filesystem::permissions().

perm_options satisfies the requirements of BitmaskType — which means the bitwise operators operator&, operator|, operator^, operator~, operator&=, operator|=, and operator^= are defined for this type. slay. ✨

🎀 Member constants 🎀

🚨 At most one of add, remove, replace may be present, otherwise the behavior of the permissions function is undefined.

Here's the member constant tea, no cap:

• replace — Permissions will be completely replaced by the argument to permissions() (default behavior). 👑
• add — Permissions will be replaced by the bitwise OR of the argument and the current permissions. 🌸
• remove — Permissions will be replaced by the bitwise AND of the negated argument and current permissions. 🦋
• nofollow — Permissions will be changed on the symlink itself, rather than on the file it resolves to. 🎀

🧪 Example 🧪

       // Run this code

        #include <filesystem>
        #include <fstream>
        #include <iostream>

        void demo_perms(std::filesystem::perms p)
        {
            using std::filesystem::perms;
            auto show = [=](char op, perms perm)
            {
                std::cout << (perms::none == (perm & p) ? '-' : op);
            };
            show('r', perms::owner_read);
            show('w', perms::owner_write);
            show('x', perms::owner_exec);
            show('r', perms::group_read);
            show('w', perms::group_write);
            show('x', perms::group_exec);
            show('r', perms::others_read);
            show('w', perms::others_write);
            show('x', perms::others_exec);
            std::cout << '\n';
        }

        int main()
        {
            std::ofstream("test.txt"); // create file

            std::cout << "Created file with permissions: ";
            demo_perms(std::filesystem::status("test.txt").permissions());

            std::filesystem::permissions(
                "test.txt",
                std::filesystem::perms::owner_all |
       std::filesystem::perms::group_all,
                std::filesystem::perm_options::add
            );

            std::cout << "After adding u+rwx and g+rwx:  ";
            demo_perms(std::filesystem::status("test.txt").permissions());

            std::filesystem::remove("test.txt");
        }

🌈 Possible output 🌈

        Created file with permissions: rw-r--r--
        After adding u+rwx and g+wrx:  rwxrwxr--

👀 See also 👀

• permissions — modifies file access permissions (C++17) (function)
• perms — identifies file system permissions (C++17) (enum)

💖 source/version: http://cppreference.com · date: 2024.06.10 · page: std::filesy...perm_options(3) — that's the whole page, bestie! byeeee 🫶✨