wp_is_internal_link( string $link ): bool
- Since
- 6.2.0
- Source
wp-includes/link-template.php:4898
Compatibility
- WordPress
- since 6.2.0
- 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.
Parameters
$linkstring- The URL to test.
Return value
bool- Returns true for internal URLs and false for all other URLs.
Performance profile
How much work a call to wp_is_internal_link() 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
- 15–23
- 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 24.
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 it touches
- hookthird-party callbacks
apply_filters()one call below wp_is_internal_link()
Further down the call graph this can also reach option, cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
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_is_internal_link() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 15 | strtolower(), wp_parse_url(), wp_allowed_protocols() |
| always | 23 | strtolower(), wp_parse_url(), wp_allowed_protocols(), wp_parse_url(), wp_internal_hosts() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 24 | 15–23 | 1 | |
| 8.5 | 24 | 15–23 | 1 | |
| 8.4 | 24 | 15–23 | 1 | 6 fewer instructions than PHP 8.3 |
| 8.3 | 30 | 18–29 | 1 | |
| 8.2 | 30 | 18–29 | 1 | |
| 8.1 | 30 | 18–29 | 1 | |
| 7.4 | 30 | 18–29 | 1 |
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 · 3
- wp_parse_url()A wrapper for PHP's parse_url() function that handles consistency in the return values across PHP versions.
- wp_allowed_protocols()Retrieves a list of protocols to allow in HTML attributes.
- wp_internal_hosts()Returns an array of URL hosts which are considered to be internal hosts.
Used by · 3
- _make_clickable_rel_attr()Helper function used to build the "rel" attribute for a URL when creating an anchor using make_clickable().
- get_comment_author_link()Retrieves the HTML link to the URL of the author of the current comment.
- wp_rel_callback()Callback to add a rel attribute to HTML A element.
Source code
function wp_is_internal_link( $link ) { $link = strtolower( $link ); if ( in_array( wp_parse_url( $link, PHP_URL_SCHEME ), wp_allowed_protocols(), true ) ) { return in_array( wp_parse_url( $link, PHP_URL_HOST ), wp_internal_hosts(), true ); } return false;}Changelog
Introduced in 6.2.0. 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/link-template.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.