std::filesystem::absolute

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

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

Parameters

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::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 except for when p is the empty path.

For Windows, std::filesystem::absolute may be implemented as a call to GetFullPathNameW.

Example

#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;
 
int main()
{
    std::filesystem::path p = "foo.c";
    std::cout << "Current path is " << std::filesystem::current_path() << '\n';
    std::cout << "Absolute path for " << p << " is " << fs::absolute(p) << '\n';
}

Current path is "/tmp/1666297965.0051296"
Absolute path for "foo.c" is "/tmp/1666297965.0051296/foo.c"

See also