_wp_get_attachment_relative_path( string $file ): string
- Since
- 4.4.1
- Source
wp-includes/media.php:1230
Compatibility
- WordPress
- since 4.4.1
- 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
$filestring- Attachment file name.
Return value
string- Attachment path relative to the upload directory.
Performance profile
How much work a call to _wp_get_attachment_relative_path() 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
- Trivial
- Scaling
- Constant
- Instructions
- 5–16
- Plugin surface
- None
- Called by
- 3
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 17.
Nothing here hands control to plugin code.
3 places in core call this, so the cost is paid more often than your own code shows.
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost _wp_get_attachment_relative_path() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 5–7 | none |
$dirname !== "." && $dirname | 16 | ltrim() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 17 | 5–16 | 2 | |
| 8.5 | 17 | 5–16 | 2 | |
| 8.4 | 17 | 5–16 | 2 | 12 fewer instructions than PHP 8.3 |
| 8.3 | 29 | 8–28 | 2 | |
| 8.2 | 29 | 8–28 | 2 | |
| 8.1 | 29 | 8–28 | 2 | |
| 7.4 | 29 | 8–28 | 2 |
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
- str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
Used by · 3
- wp_calculate_image_srcset()A helper function to calculate the image sources to include in a 'srcset' attribute.
- wp_get_attachment_url()Retrieves the URL for an attachment.
- wp_image_file_matches_image_meta()Determines if the image meta data is for the image source file.
Source code
function _wp_get_attachment_relative_path( $file ) { $dirname = dirname( $file ); if ( '.' === $dirname ) { return ''; } if ( str_contains( $dirname, 'wp-content/uploads' ) ) { // Get the directory name relative to the upload directory (back compat for pre-2.7 uploads). $dirname = substr( $dirname, strpos( $dirname, 'wp-content/uploads' ) + 18 ); $dirname = ltrim( $dirname, '/' ); } return $dirname;}Changelog
Introduced in 4.4.1. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.8.8 tag, from
src/wp-includes/media.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.