std::filesystem::perm_options
From cppreference.com
< cpp | filesystem
| Defined in header <filesystem>
|
||
enum class perm_options { replace = /* unspecified */, add = /* unspecified */, remove = /* unspecified */, nofollow = /* unspecified */ }; |
(since C++17) | |
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).
Member constants
At most one of add, remove, replace may be present, otherwise the behavior of the permissions function is undefined.
| Enumerator | Meaning |
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
(C++17) |
modifies file access permissions (function) |
(C++17) |
identifies file system permissions (enum) |