std::filesystem::path::replace_extension

 

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Filesystem library

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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
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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
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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

 

std::filesystem::path

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path::native_formatpath::generic_formatpath::auto_format
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path::path path::~path path::operator= path::assign path::appendpath::operator /= path::concatpath::operator += path::clear path::make_preferred path::remove_filename path::replace_filename path::replace_extension      path::swap path::compare path::beginpath::end	path::c_strpath::nativepath::operator string_type path::stringpath::u8stringpath::u16stringpath::u32stringpath::wstring path::generic_stringpath::generic_u8stringpath::generic_u16stringpath::generic_u32stringpath::generic_wstring path::lexically_normalpath::lexically_relativepath::lexically_proximate
Path decomposition
path::root_name path::root_directory path::root_path path::relative_path path::parent_path path::filename path::stem path::extension path::empty	path::has_root_pathpath::has_root_namepath::has_root_directorypath::has_relative_pathpath::has_parent_pathpath::has_filenamepath::has_stempath::has_extension path::is_absolutepath::is_relative
Non-member functions
operator==operator!=operator<operator<=operator>operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)	operator/ operator<<operator>> swap(path) hash_value u8path
Helper Classes
hash

 

path& replace_extension( const path& replacement = path() );		(since C++17)

Replaces the extension with replacement or removes it when the default value of replacement is used.

Firstly, if this path has an extension(), it is removed from the generic-format view of the pathname.

Then, a dot character is appended to the generic-format view of the pathname, if replacement is not empty and does not begin with a dot character.

Then replacement is appended as if by operator+=(replacement).

Parameters

replacement

-

the extension to replace with

Return value

*this

Exceptions

May throw implementation-defined exceptions.

Notes

The type of replacement is std::filesystem::path even though it is not intended to represent an object on the file system in order to correctly account for the filesystem character encoding.

Example

Run this code

#include <filesystem>
#include <iomanip>
#include <iostream>
#include <utility>
namespace fs = std::filesystem;
 
int main()
{
    std::cout << "Path:             Ext:       Result:\n" << std::left;
    for (const auto& [path, extension] : {
            std::make_pair( "/foo/bar.jpg", ".png" ),
            std::make_pair( "/foo/bar.jpg", "png"  ),
            std::make_pair( "/foo/bar.jpg", "."    ),
            std::make_pair( "/foo/bar.jpg", ""     ),
            std::make_pair( "/foo/bar."   , "png"  ),
            std::make_pair( "/foo/bar"    , ".png" ),
            std::make_pair( "/foo/bar"    , "png"  ),
            std::make_pair( "/foo/bar"    , "."    ),
            std::make_pair( "/foo/bar"    , ""     ),
            std::make_pair( "/foo/."      , ".png" ),
            std::make_pair( "/foo/."      , "png"  ),
            std::make_pair( "/foo/."      , "."    ),
            std::make_pair( "/foo/."      , ""     ),
            std::make_pair( "/foo/"       , ".png" ),
            std::make_pair( "/foo/"       , "png"  ), })
    {
        fs::path p = path, e = extension;
        std::cout << std::setw(18) << p << std::setw(11) << e;
        p.replace_extension(e);
        std::cout << p << '\n';
    }
}

Output:

Path:             Ext:       Result:
"/foo/bar.jpg"    ".png"     "/foo/bar.png"
"/foo/bar.jpg"    "png"      "/foo/bar.png"
"/foo/bar.jpg"    "."        "/foo/bar."
"/foo/bar.jpg"    ""         "/foo/bar"
"/foo/bar."       "png"      "/foo/bar.png"
"/foo/bar"        ".png"     "/foo/bar.png"
"/foo/bar"        "png"      "/foo/bar.png"
"/foo/bar"        "."        "/foo/bar."
"/foo/bar"        ""         "/foo/bar"
"/foo/."          ".png"     "/foo/..png"
"/foo/."          "png"      "/foo/..png"
"/foo/."          "."        "/foo/.."
"/foo/."          ""         "/foo/."
"/foo/"           ".png"     "/foo/.png"
"/foo/"           "png"      "/foo/.png"

See also

extension	returns the file extension path component (public member function)
filename	returns the filename path component (public member function)
stem	returns the stem path component (filename without the final extension) (public member function)
has_extension	checks if the corresponding path element is not empty (public member function)