wp_check_filetype_and_ext( string $file, string $filename, array $mimes = null )
Attempt to determine the real file type of a file.
Description
If unable to, the file name extension will be used to determine type.
If it’s determined that the extension does not match the file’s real type, then the "proper_filename" value will be set with a proper filename and extension.
Currently this function only supports renaming images validated via wp_get_image_mime().
Parameters
- $file
-
(Required) Full path to the file.
- $filename
-
(Required) The name of the file (may differ from $file due to $file being in a tmp directory).
- $mimes
-
(Optional) Key is the file extension with value as the mime type.
Default value: null
Return
(array) Values for the extension, MIME, and either a corrected filename or false if original $filename is valid.
Source
File: wp-includes/functions.php
function wp_check_filetype_and_ext( $file, $filename, $mimes = null ) {
$proper_filename = false;
// Do basic extension validation and MIME mapping
$wp_filetype = wp_check_filetype( $filename, $mimes );
$ext = $wp_filetype['ext'];
$type = $wp_filetype['type'];
// We can't do any further validation without a file to work with
if ( ! file_exists( $file ) ) {
return compact( 'ext', 'type', 'proper_filename' );
}
$real_mime = false;
// Validate image types.
if ( $type && 0 === strpos( $type, 'image/' ) ) {
// Attempt to figure out what type of image it actually is
$real_mime = wp_get_image_mime( $file );
if ( $real_mime && $real_mime != $type ) {
/**
* Filters the list mapping image mime types to their respective extensions.
*
* @since WP-3.0.0
*
* @param array $mime_to_ext Array of image mime types and their matching extensions.
*/
$mime_to_ext = apply_filters( 'getimagesize_mimes_to_exts', array(
'image/jpeg' => 'jpg',
'image/png' => 'png',
'image/gif' => 'gif',
'image/bmp' => 'bmp',
'image/tiff' => 'tif',
) );
// Replace whatever is after the last period in the filename with the correct extension
if ( ! empty( $mime_to_ext[ $real_mime ] ) ) {
$filename_parts = explode( '.', $filename );
array_pop( $filename_parts );
$filename_parts[] = $mime_to_ext[ $real_mime ];
$new_filename = implode( '.', $filename_parts );
if ( $new_filename != $filename ) {
$proper_filename = $new_filename; // Mark that it changed
}
// Redefine the extension / MIME
$wp_filetype = wp_check_filetype( $new_filename, $mimes );
$ext = $wp_filetype['ext'];
$type = $wp_filetype['type'];
} else {
// Reset $real_mime and try validating again.
$real_mime = false;
}
}
}
// Validate files that didn't get validated during previous checks.
if ( $type && ! $real_mime && extension_loaded( 'fileinfo' ) ) {
$finfo = finfo_open( FILEINFO_MIME_TYPE );
$real_mime = finfo_file( $finfo, $file );
finfo_close( $finfo );
// fileinfo often misidentifies obscure files as one of these types
$nonspecific_types = array(
'application/octet-stream',
'application/encrypted',
'application/CDFV2-encrypted',
'application/zip',
);
/*
* If $real_mime doesn't match the content type we're expecting from the file's extension,
* we need to do some additional vetting. Media types and those listed in $nonspecific_types are
* allowed some leeway, but anything else must exactly match the real content type.
*/
if ( in_array( $real_mime, $nonspecific_types, true ) ) {
// File is a non-specific binary type. That's ok if it's a type that generally tends to be binary.
if ( !in_array( substr( $type, 0, strcspn( $type, '/' ) ), array( 'application', 'video', 'audio' ) ) ) {
$type = $ext = false;
}
} elseif ( 0 === strpos( $real_mime, 'video/' ) || 0 === strpos( $real_mime, 'audio/' ) ) {
/*
* For these types, only the major type must match the real value.
* This means that common mismatches are forgiven: application/vnd.apple.numbers is often misidentified as application/zip,
* and some media files are commonly named with the wrong extension (.mov instead of .mp4)
*/
if ( substr( $real_mime, 0, strcspn( $real_mime, '/' ) ) !== substr( $type, 0, strcspn( $type, '/' ) ) ) {
$type = $ext = false;
}
} elseif ( 'text/plain' === $real_mime ) {
// A few common file types are occasionally detected as text/plain; allow those.
if ( ! in_array(
$type,
array(
'text/plain',
'text/csv',
'text/richtext',
'text/tsv',
'text/vtt',
)
)
) {
$type = $ext = false;
}
} elseif ( 'text/rtf' === $real_mime ) {
// Special casing for RTF files.
if ( ! in_array(
$type,
array(
'text/rtf',
'text/plain',
'application/rtf',
)
)
) {
$type = $ext = false;
}
} else {
if ( $type !== $real_mime ) {
/*
* Everything else including image/* and application/*:
* If the real content type doesn't match the file extension, assume it's dangerous.
*/
$type = $ext = false;
}
}
}
// The mime type must be allowed
if ( $type ) {
$allowed = get_allowed_mime_types();
if ( ! in_array( $type, $allowed ) ) {
$type = $ext = false;
}
}
/**
* Filters the "real" file type of the given file.
*
* @since WP-3.0.0
* @since WP-5.1.0 The $real_mime parameter was added.
*
* @param array $wp_check_filetype_and_ext File data array containing 'ext', 'type', and
* 'proper_filename' keys.
* @param string $file Full path to the file.
* @param string $filename The name of the file (may differ from $file due to
* $file being in a tmp directory).
* @param array $mimes Key is the file extension with value as the mime type.
* @param string|bool $real_mime The actual mime type or false if the type cannot be determined.
*/
return apply_filters( 'wp_check_filetype_and_ext', compact( 'ext', 'type', 'proper_filename' ), $file, $filename, $mimes, $real_mime );
}
Changelog
Version | Description |
---|---|
WP-3.0.0 | Introduced. |