Std::filesystem::absolute (3) Linux Manual Page

std::filesystem::absolute – std::filesystem::absolute

Synopsis

Defined in header<filesystem>

    path absolute(const std::filesystem::path &p);
(since C++ 17)

    path absolute(const std::filesystem::path &p, std::error_code &ec);

Returns a path referencing the same file system location as p, for which is_absolute() is true. The non-throwing overload returns default-constructed path if an error occurs.

Parameters

p – path to convert to absolute form
ec – out-parameter for error reporting in the non-throwing overload

Return value

Returns an absolute (although not necessarily canonical) pathname referencing the same file as p

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.

Notes

Implementations are encouraged to not consider p not existing to be an error.
For POSIX-based operating systems, std::filesystem::absolute(p) is equivalent to std::filesystem::current_path() / p
For Windows, absolute may be implemented as a call to GetFullPathNameW.

Example

// Run this code

#include <iostream>

#include <filesystem>

namespace fs = std::filesystem;

int main()

{
    fs::path p = "C:cl.exe";
    std::cout << "Current path is " << fs::current_path() << '\n'
              << "Absolute path for " << p << " is " << fs::absolute(p) << '\n';

    // actual location: "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\cl.exe"
}

Possible output:

Current path is "D:/local/ConsoleApplication1"
Absolute path for "C:cl.exe" is "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\cl.exe"

std::filesystem::absolute (3) Linux Manual Page