std::filesystem:: read_symlink

From cppreference.com
C++
Filesystem library
Classes
Functions
File types
Defined in header <filesystem>
(1) (since C++17)
(2) (since C++17)

If the path p refers to a symbolic link, returns a new path object which refers to the target of that symbolic link.

It is an error if p does not refer to a symbolic link.

The non-throwing overload returns an empty path on errors.

Parameters

p - path to a symlink
ec - out-parameter for error reporting in the non-throwing overload

Return value

The target of the symlink (which may not necessarily exist).

Exceptions

Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.

1) Throws std::filesystem::filesystem_error on underlying OS API errors, constructed with p as the first path argument and the OS error code as the error code argument.
2) Sets a std:: error_code & parameter to the OS API error code if an OS API call fails, and executes ec. clear ( ) if no errors occur.

Example

Run this code 
#include <filesystem>
#include <iostream>
 
namespace fs = std::filesystem;
 
int main()
{
    for (fs::path p : {"/usr/bin/gcc", "/bin/cat", "/bin/mouse"})
    {
        std::cout << p;
        fs::exists(p) ?
            fs::is_symlink(p) ?
                std::cout << " -> " << fs::read_symlink(p) << '\n' :
                std::cout << " exists but it is not a symlink\n" :
            std::cout << " does not exist\n";
    }
}

Possible output: 

"/usr/bin/gcc" -> "gcc-5"
"/bin/cat" exists but it is not a symlink
"/bin/mouse" does not exist

See also

(C++17)
checks whether the argument refers to a symbolic link
(function)
(C++17) (C++17)
creates a symbolic link
(function)
(C++17)
copies a symbolic link
(function)
(C++17) (C++17)
determines file attributes
determines file attributes, checking the symlink target
(function)
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