wp_set_lang_dir()
- Since
- 3.0.0
- Source
wp-includes/load.php:663
Description
To set directory manually, define the WP_LANG_DIR constant in wp-config.php.
If the language directory exists within WP_CONTENT_DIR, it is used. Otherwise the language directory is assumed to live in WPINC.
Compatibility
- WordPress
- since 3.0.0
- 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.
Performance profile
How much work a call to wp_set_lang_dir() 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
- Heavy
- Scaling
- Constant
- Instructions
- 3–43
- Plugin surface
- None
- Called by
- 0
Reads or writes the filesystem via file_exists().
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 53.
Nothing here hands control to plugin code.
Nothing in core calls this; the cost is only what you spend yourself.
What it touches
- filesystemfilesystem access
file_exists()called directly
What one call costs · 5 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_set_lang_dir() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
defined('WP_LANG_DIR') | 3 | none |
!defined('WP_LANG_DIR') | 25–29 | file_exists(), is_dir(), define() |
!defined('WP_LANG_DIR') && !file_exists() && is_dir() && !defined('LANGDIR') | 35 | file_exists(), is_dir(), define(), define() |
!defined('WP_LANG_DIR') && file_exists() && !is_dir() | 35–37 | file_exists(), is_dir(), is_dir(), define() |
!defined('WP_LANG_DIR') && file_exists() && !defined('LANGDIR') | 43 | file_exists(), is_dir(), is_dir(), define(), define() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 53 instructions, 3–43 executed per call, 6 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.
Source code
function wp_set_lang_dir() { if ( ! defined( 'WP_LANG_DIR' ) ) { if ( file_exists( WP_CONTENT_DIR . '/languages' ) && @is_dir( WP_CONTENT_DIR . '/languages' ) || ! @is_dir( ABSPATH . WPINC . '/languages' ) ) { /** * Server path of the language directory. * * No leading slash, no trailing slash, full path, not relative to ABSPATH * * @since 2.1.0 */ define( 'WP_LANG_DIR', WP_CONTENT_DIR . '/languages' ); if ( ! defined( 'LANGDIR' ) ) { // Old static relative path maintained for limited backward compatibility - won't work in some cases. define( 'LANGDIR', 'wp-content/languages' ); } } else { /** * Server path of the language directory. * * No leading slash, no trailing slash, full path, not relative to `ABSPATH`. * * @since 2.1.0 */ define( 'WP_LANG_DIR', ABSPATH . WPINC . '/languages' ); if ( ! defined( 'LANGDIR' ) ) { // Old relative path maintained for backward compatibility. define( 'LANGDIR', WPINC . '/languages' ); } } }}Changelog
Introduced in 3.0.0. 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 7.1.0 tag, from
src/wp-includes/load.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.