Question

wp_unique_filename( string $dir,  string $filename,  callable $unique_filename_callback = null )

Get a filename that is sanitized and unique for the given directory.

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description

If the filename is not unique, then a number will be added to the filename before the extension, and will continue adding numbers until the filename is unique.

The callback is passed three parameters, the first one is the directory, the second is the filename, and the third is the extension.

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参数

$dir

(string) (Required) Directory.

$filename

(string) (Required) File name.

$unique_filename_callback

(callable) (Optional) Callback.

Default value: null

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返回值

(string) New filename, if given wasn't unique.

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源代码

File: wp-includes/functions.php

function wp_unique_filename( $dir, $filename, $unique_filename_callback = null ) {
	// Sanitize the file name before we begin processing.
	$filename = sanitize_file_name($filename);

	// 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 {
		$number = '';

		// Change '.ext' to lower case.
		if ( $ext && strtolower($ext) != $ext ) {
			$ext2 = strtolower($ext);
			$filename2 = preg_replace( '|' . preg_quote($ext) . '$|', $ext2, $filename );

			// Check for both lower and upper case extension or image sub-sizes may be overwritten.
			while ( file_exists($dir . "/$filename") || file_exists($dir . "/$filename2") ) {
				$new_number = (int) $number + 1;
				$filename = str_replace( array( "-$number$ext", "$number$ext" ), "-$new_number$ext", $filename );
				$filename2 = str_replace( array( "-$number$ext2", "$number$ext2" ), "-$new_number$ext2", $filename2 );
				$number = $new_number;
			}

			/**
			 * Filters the result when generating a unique file name.
			 *
			 * @since 4.5.0
			 *
			 * @param string        $filename                 Unique file name.
			 * @param string        $ext                      File extension, eg. ".png".
			 * @param string        $dir                      Directory path.
			 * @param callable|null $unique_filename_callback Callback function that generates the unique file name.
			 */
			return apply_filters( 'wp_unique_filename', $filename2, $ext, $dir, $unique_filename_callback );
		}

		while ( file_exists( $dir . "/$filename" ) ) {
			$new_number = (int) $number + 1;
			if ( '' == "$number$ext" ) {
				$filename = "$filename-" . $new_number;
			} else {
				$filename = str_replace( array( "-$number$ext", "$number$ext" ), "-" . $new_number . $ext, $filename );
			}
			$number = $new_number;
		}
	}

	/** This filter is documented in wp-includes/functions.php */
	return apply_filters( 'wp_unique_filename', $filename, $ext, $dir, $unique_filename_callback );
}

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更新日志

Version	description
2.5.0	Introduced.

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相关函数

Uses

• wp-includes/functions.php: wp_unique_filename
• wp-includes/formatting.php: sanitize_file_name()
• wp-includes/plugin.php: apply_filters()

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Used By

• wp-admin/includes/file.php: _wp_handle_upload()
• wp-admin/includes/image.php: _copy_image_file()
• wp-admin/includes/image.php: wp_generate_attachment_metadata()
• wp-admin/includes/image.php: wp_crop_image()
• wp-admin/includes/file.php: wp_tempnam()
• wp-includes/functions.php: wp_upload_bits()
Show 1 more used by Hide more used by

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User Contributed Notes

1. Skip to note content You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note Contributed by Codex

   Example

   
   $newfilename = wp_unique_filename( $path_being_saved_to, $filename_to_check );