wp_check_filetype( string $filename, string[]|null $mimes = null ): array
- Since
- 2.0.4
- Source
wp-includes/functions.php:3047
Description
You can optionally define the mime array, if needed.
Compatibility
- WordPress
- since 2.0.4
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$filenamestring- File name or path.
$mimesstring[]|nulloptional- Array of allowed mime types keyed by their file extension regex.
Defaults to the result of get_allowed_mime_types().Default:null
Return value
array- Values for the extension and mime type.
$extstring|falseFile extension, or false if the file doesn't match a mime type.$typestring|falseFile mime type, or false if the file doesn't match a mime type.
Performance profile
How much work a call to wp_check_filetype() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Light
- Scaling
- Scales with input
- Instructions
- 13–30
- Plugin surface
- None
- Called by
- 12
Touches nothing outside its own arguments.
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 30.
Nothing here hands control to plugin code.
12 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()one call below wp_check_filetype()
Further down the call graph this can also reach query. That is the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 4 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_check_filetype() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!empty($mimes) | 13–14 | compact() |
empty($mimes) | 16–17 | get_allowed_mime_types(), compact() |
!empty($mimes) && !$mimes && preg_match() | 27 | preg_match(), compact() |
empty($mimes) && !$mimes && preg_match() | 30 | get_allowed_mime_types(), preg_match(), compact() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 30 instructions, 13–30 executed per call, 4 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 1
- get_allowed_mime_types()Retrieves the list of allowed mime types and file extensions.
Used by · 12
- WP_Customize_Manager::prepare_starter_content_attachments()Prepares starter content attachments.
- WP_Theme_JSON_Resolver::get_resolved_theme_uris()Resolves relative paths in theme.json styles to theme absolute paths and returns them in an array that can be embedded as the value of `_link` object in REST API responses.
- get_header_video_settings()Retrieves header video settings.
- sanitize_file_name()Sanitizes a filename, replacing whitespace with dashes.
- wp_attachment_is()Verifies an attachment is of a given type.
- wp_audio_shortcode()Builds the Audio shortcode output.
- wp_check_filetype_and_ext()Attempts to determine the real file type of a file.
- wp_get_image_editor()Returns a WP_Image_Editor instance and loads file into it.
- wp_playlist_shortcode()Builds the Playlist shortcode output.
- wp_unique_filename()Gets a filename that is sanitized and unique for the given directory.
- wp_upload_bits()Creates a file in the upload folder with given content.
- wp_video_shortcode()Builds the Video shortcode output.
Source code
function wp_check_filetype( $filename, $mimes = null ) { if ( empty( $mimes ) ) { $mimes = get_allowed_mime_types(); } $type = false; $ext = false; foreach ( $mimes as $ext_preg => $mime_match ) { $ext_preg = '!\.(' . $ext_preg . ')$!i'; if ( preg_match( $ext_preg, $filename, $ext_matches ) ) { $type = $mime_match; $ext = $ext_matches[1]; break; } } return compact( 'ext', 'type' );}Changelog
Introduced in 2.0.4. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
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src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
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