std::filesystem::read_symlink

 

C++

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Filesystem library (C++17)

Technical Specifications

 

Filesystem library

Classes
filesystem::path filesystem::filesystem_error filesystem::directory_entry filesystem::directory_iterator filesystem::recursive_directory_iterator filesystem::file_status	filesystem::space_info filesystem::file_type filesystem::perms filesystem::perm_options filesystem::copy_options filesystem::directory_options filesystem::file_time_type
Functions
filesystem::absolute filesystem::canonicalfilesystem::weakly_canonical filesystem::relativefilesystem::proximate filesystem::copy filesystem::copy_file filesystem::copy_symlink filesystem::create_directory filesystem::create_directories filesystem::create_hard_link filesystem::create_symlink filesystem::create_directory_symlink filesystem::current_path	filesystem::exists filesystem::equivalent filesystem::file_size filesystem::hard_link_count filesystem::last_write_time filesystem::permissions filesystem::read_symlink filesystem::remove filesystem::remove_all filesystem::rename filesystem::resize_file filesystem::space filesystem::status filesystem::symlink_status filesystem::temp_directory_path
File types
filesystem::is_block_file filesystem::is_character_file filesystem::is_directory filesystem::is_empty filesystem::status_known	filesystem::is_fifo filesystem::is_other filesystem::is_regular_file filesystem::is_socket filesystem::is_symlink

 

Defined in header <filesystem>
std::filesystem::path read_symlink(const std::filesystem::path& p); std::filesystem::path read_symlink(const std::filesystem::path& p,                                    std::error_code& ec);		(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

The overload that does not take a std::error_code& parameter throws 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. The overload taking a std::error_code& parameter sets it to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur. Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.

Example

Run this code

#include <iostream>
#include <filesystem>
 
namespace fs = std::filesystem;
 
int main()
{
    // on a typical Linux system, /lib/libc.so.6 is a symlink
    fs::path p = "/lib/libc.so.6";
    if(fs::exists(p) && fs::is_symlink(p))
        std::cout << p << " -> " << fs::read_symlink(p) << '\n';
    else
        std::cout << p << " does not exist or is not a symlink\n";
}

Possible output:

"/lib/libc.so.6" -> "libc-2.12.so"

See also

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