std::filesystem::absolute

 

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Technical specifications

Symbols index

External libraries

 

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>
path absolute( const std::filesystem::path& p ); path absolute( const std::filesystem::path& p, std::error_code& ec );		(since C++17)

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

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::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

Run this code

#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';
}

Possible output:

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

See also

canonicalweakly_canonical (C++17)	composes a canonical path (function)
relativeproximate (C++17)	composes a relative path (function)