Уникализирует имя файла. Используется перед сохранением файла в указанную папку, чтобы изменить его имя, если такой файл уже существует.
Если файл в таким именем существует в директории, то функция добавит в конец имени файла число и проверит новое имя. И так до тех пор, пока имя не станет уникальным. Функция вернет уникальное имя файла.
В третий параметр функции $unique_filename_callback можно передать название функции, которая будет уникализировать имя файла. По умолчанию к названию файла прибавляются цифры: name1.jpg, name2.jpg и т.д.
Заметка: wp_unique_filename() автоматически использует, функцию очистки имени файла sanitize_file_name().
Путь до каталога (директории), в котором находится файл.
$filename(строка) (обязательный)
Имя файла (только имя, не путь с именем), который нужно проверить на уникальность.
$unique_filename_callback(callback)
Название функции, которая будет проверять уникальность. По умолчанию - встроенная функция. По умолчанию: null
Примеры
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#1 Уникализируем имя файла перед сохранением его в каталог
Допустим мы сохраняем файл file.jpg в каталог /home/files и там уже есть файл с таким именем. Тогда, чтобы не перезаписать имеющийся файл новым, а добавить новый файл, мы можем создать новое уникальное имя налету, так:
function wp_unique_filename( $dir, $filename, $unique_filename_callback = null ) {
// Sanitize the file name before we begin processing.
$filename = sanitize_file_name( $filename );
$ext2 = null;
// Initialize vars used in the wp_unique_filename filter.
$number = '';
$alt_filenames = array();
// Separate the filename into a name and extension.
$ext = pathinfo( $filename, PATHINFO_EXTENSION );
$name = pathinfo( $filename, PATHINFO_BASENAME );
if ( $ext ) {
$ext = '.' . $ext;
}
// Edge case: if file is named '.ext', treat as an empty name.
if ( $name === $ext ) {
$name = '';
}
/*
* Increment the file number until we have a unique file to save in $dir.
* Use callback if supplied.
*/
if ( $unique_filename_callback && is_callable( $unique_filename_callback ) ) {
$filename = call_user_func( $unique_filename_callback, $dir, $name, $ext );
} else {
$fname = pathinfo( $filename, PATHINFO_FILENAME );
// Always append a number to file names that can potentially match image sub-size file names.
if ( $fname && preg_match( '/-(?:\d+x\d+|scaled|rotated)$/', $fname ) ) {
$number = 1;
// At this point the file name may not be unique. This is tested below and the $number is incremented.
$filename = str_replace( "{$fname}{$ext}", "{$fname}-{$number}{$ext}", $filename );
}
/*
* Get the mime type. Uploaded files were already checked with wp_check_filetype_and_ext()
* in _wp_handle_upload(). Using wp_check_filetype() would be sufficient here.
*/
$file_type = wp_check_filetype( $filename );
$mime_type = $file_type['type'];
$is_image = ( ! empty( $mime_type ) && str_starts_with( $mime_type, 'image/' ) );
$upload_dir = wp_get_upload_dir();
$lc_filename = null;
$lc_ext = strtolower( $ext );
$_dir = trailingslashit( $dir );
/*
* If the extension is uppercase add an alternate file name with lowercase extension.
* Both need to be tested for uniqueness as the extension will be changed to lowercase
* for better compatibility with different filesystems. Fixes an inconsistency in WP < 2.9
* where uppercase extensions were allowed but image sub-sizes were created with
* lowercase extensions.
*/
if ( $ext && $lc_ext !== $ext ) {
$lc_filename = preg_replace( '|' . preg_quote( $ext ) . '$|', $lc_ext, $filename );
}
/*
* Increment the number added to the file name if there are any files in $dir
* whose names match one of the possible name variations.
*/
while ( file_exists( $_dir . $filename ) || ( $lc_filename && file_exists( $_dir . $lc_filename ) ) ) {
$new_number = (int) $number + 1;
if ( $lc_filename ) {
$lc_filename = str_replace(
array( "-{$number}{$lc_ext}", "{$number}{$lc_ext}" ),
"-{$new_number}{$lc_ext}",
$lc_filename
);
}
if ( '' === "{$number}{$ext}" ) {
$filename = "{$filename}-{$new_number}";
} else {
$filename = str_replace(
array( "-{$number}{$ext}", "{$number}{$ext}" ),
"-{$new_number}{$ext}",
$filename
);
}
$number = $new_number;
}
// Change the extension to lowercase if needed.
if ( $lc_filename ) {
$filename = $lc_filename;
}
/*
* Prevent collisions with existing file names that contain dimension-like strings
* (whether they are subsizes or originals uploaded prior to #42437).
*/
$files = array();
$count = 10000;
// The (resized) image files would have name and extension, and will be in the uploads dir.
if ( $name && $ext && @is_dir( $dir ) && str_contains( $dir, $upload_dir['basedir'] ) ) {
/**
* Filters the file list used for calculating a unique filename for a newly added file.
*
* Returning an array from the filter will effectively short-circuit retrieval
* from the filesystem and return the passed value instead.
*
* @since 5.5.0
*
* @param array|null $files The list of files to use for filename comparisons.
* Default null (to retrieve the list from the filesystem).
* @param string $dir The directory for the new file.
* @param string $filename The proposed filename for the new file.
*/
$files = apply_filters( 'pre_wp_unique_filename_file_list', null, $dir, $filename );
if ( null === $files ) {
// List of all files and directories contained in $dir.
$files = @scandir( $dir );
}
if ( ! empty( $files ) ) {
// Remove "dot" dirs.
$files = array_diff( $files, array( '.', '..' ) );
}
if ( ! empty( $files ) ) {
$count = count( $files );
/*
* Ensure this never goes into infinite loop as it uses pathinfo() and regex in the check,
* but string replacement for the changes.
*/
$i = 0;
while ( $i <= $count && _wp_check_existing_file_names( $filename, $files ) ) {
$new_number = (int) $number + 1;
// If $ext is uppercase it was replaced with the lowercase version after the previous loop.
$filename = str_replace(
array( "-{$number}{$lc_ext}", "{$number}{$lc_ext}" ),
"-{$new_number}{$lc_ext}",
$filename
);
$number = $new_number;
++$i;
}
}
}
/*
* Check if an image will be converted after uploading or some existing image sub-size file names may conflict
* when regenerated. If yes, ensure the new file name will be unique and will produce unique sub-sizes.
*/
if ( $is_image ) {
/** This filter is documented in wp-includes/class-wp-image-editor.php */
$output_formats = apply_filters( 'image_editor_output_format', array(), $_dir . $filename, $mime_type );
$alt_types = array();
if ( ! empty( $output_formats[ $mime_type ] ) ) {
// The image will be converted to this format/mime type.
$alt_mime_type = $output_formats[ $mime_type ];
// Other types of images whose names may conflict if their sub-sizes are regenerated.
$alt_types = array_keys( array_intersect( $output_formats, array( $mime_type, $alt_mime_type ) ) );
$alt_types[] = $alt_mime_type;
} elseif ( ! empty( $output_formats ) ) {
$alt_types = array_keys( array_intersect( $output_formats, array( $mime_type ) ) );
}
// Remove duplicates and the original mime type. It will be added later if needed.
$alt_types = array_unique( array_diff( $alt_types, array( $mime_type ) ) );
foreach ( $alt_types as $alt_type ) {
$alt_ext = wp_get_default_extension_for_mime_type( $alt_type );
if ( ! $alt_ext ) {
continue;
}
$alt_ext = ".{$alt_ext}";
$alt_filename = preg_replace( '|' . preg_quote( $lc_ext ) . '$|', $alt_ext, $filename );
$alt_filenames[ $alt_ext ] = $alt_filename;
}
if ( ! empty( $alt_filenames ) ) {
/*
* Add the original filename. It needs to be checked again
* together with the alternate filenames when $number is incremented.
*/
$alt_filenames[ $lc_ext ] = $filename;
// Ensure no infinite loop.
$i = 0;
while ( $i <= $count && _wp_check_alternate_file_names( $alt_filenames, $_dir, $files ) ) {
$new_number = (int) $number + 1;
foreach ( $alt_filenames as $alt_ext => $alt_filename ) {
$alt_filenames[ $alt_ext ] = str_replace(
array( "-{$number}{$alt_ext}", "{$number}{$alt_ext}" ),
"-{$new_number}{$alt_ext}",
$alt_filename
);
}
/*
* Also update the $number in (the output) $filename.
* If the extension was uppercase it was already replaced with the lowercase version.
*/
$filename = str_replace(
array( "-{$number}{$lc_ext}", "{$number}{$lc_ext}" ),
"-{$new_number}{$lc_ext}",
$filename
);
$number = $new_number;
++$i;
}
}
}
}
/**
* Filters the result when generating a unique file name.
*
* @since 4.5.0
* @since 5.8.1 The `$alt_filenames` and `$number` parameters were added.
*
* @param string $filename Unique file name.
* @param string $ext File extension. Example: ".png".
* @param string $dir Directory path.
* @param callable|null $unique_filename_callback Callback function that generates the unique file name.
* @param string[] $alt_filenames Array of alternate file names that were checked for collisions.
* @param int|string $number The highest number that was used to make the file name unique
* or an empty string if unused.
*/
return apply_filters( 'wp_unique_filename', $filename, $ext, $dir, $unique_filename_callback, $alt_filenames, $number );
}