Title: wp-includes/functions.php | Page 2 of 10 | Developer.WordPress.org --- # File: wp-includes/functions.php * function[wp_json_file_decode()](https://developer.wordpress.org/reference/functions/wp_json_file_decode/) * Reads and decodes a JSON file. * Used by [5 functions](https://developer.wordpress.org/reference/functions/wp_json_file_decode/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/wp_json_file_decode/#uses) | Source: [wp-includes/functions.php:4725](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4725-L4758) * function[_wp_check_alternate_file_names()](https://developer.wordpress.org/reference/functions/_wp_check_alternate_file_names/) * Helper function to test if each of an array of file names could conflict with existing files. * Used by [1 function](https://developer.wordpress.org/reference/functions/_wp_check_alternate_file_names/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/_wp_check_alternate_file_names/#uses) | Source: [wp-includes/functions.php:2846](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L2846-L2858) * function[wp_get_default_extension_for_mime_type()](https://developer.wordpress.org/reference/functions/wp_get_default_extension_for_mime_type/) * Returns the first matched extension for the mime type, as mapped from wp_get_mime_types(). * Used by [2 functions](https://developer.wordpress.org/reference/functions/wp_get_default_extension_for_mime_type/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_get_default_extension_for_mime_type/#uses) | Source: [wp-includes/functions.php:3053](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L3053-L3061) * function[_wp_array_set()](https://developer.wordpress.org/reference/functions/_wp_array_set/) * Sets an array in depth based on a path of keys. * Used by [18 functions](https://developer.wordpress.org/reference/functions/_wp_array_set/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/_wp_array_set/#uses) | Source: [wp-includes/functions.php:5239](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5239-L5277) * function[_wp_to_kebab_case()](https://developer.wordpress.org/reference/functions/_wp_to_kebab_case/) * This function is trying to replicate what lodash’s kebabCase (JS library) does in the client. * Used by [10 functions](https://developer.wordpress.org/reference/functions/_wp_to_kebab_case/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/_wp_to_kebab_case/#uses) | Source: [wp-includes/functions.php:5306](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5306-L5355) * function[wp_get_update_https_url()](https://developer.wordpress.org/reference/functions/wp_get_update_https_url/) * Gets the URL to learn more about updating the site to use HTTPS. * Used by [1 function](https://developer.wordpress.org/reference/functions/wp_get_update_https_url/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/wp_get_update_https_url/#uses) | Source: [wp-includes/functions.php:8814](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L8814-L8838) * hook[wp_update_https_url](https://developer.wordpress.org/reference/hooks/wp_update_https_url/) * Filters the URL to learn more about updating the HTTPS version the site is running on. * Used by [1 function](https://developer.wordpress.org/reference/hooks/wp_update_https_url/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/wp_update_https_url/#uses) | Source: [wp-includes/functions.php:8832](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L8832-L8832) * function[wp_get_default_update_https_url()](https://developer.wordpress.org/reference/functions/wp_get_default_update_https_url/) * Gets the default URL to learn more about updating the site to use HTTPS. * Used by [2 functions](https://developer.wordpress.org/reference/functions/wp_get_default_update_https_url/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_get_default_update_https_url/#uses) | Source: [wp-includes/functions.php:8852](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L8852-L8855) * function[wp_get_direct_update_https_url()](https://developer.wordpress.org/reference/functions/wp_get_direct_update_https_url/) * Gets the URL for directly updating the site to use HTTPS. * Used by [1 function](https://developer.wordpress.org/reference/functions/wp_get_direct_update_https_url/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_get_direct_update_https_url/#uses) | Source: [wp-includes/functions.php:8868](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L8868-L8885) * hook[wp_direct_update_https_url](https://developer.wordpress.org/reference/hooks/wp_direct_update_https_url/) * Filters the URL for directly updating the PHP version the site is running on from the host. * Used by [1 function](https://developer.wordpress.org/reference/hooks/wp_direct_update_https_url/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/wp_direct_update_https_url/#uses) | Source: [wp-includes/functions.php:8882](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L8882-L8882) * hook[pre_recurse_dirsize](https://developer.wordpress.org/reference/hooks/pre_recurse_dirsize/) * Filters the amount of storage space used by one directory and all its children, in megabytes. * Used by [1 function](https://developer.wordpress.org/reference/hooks/pre_recurse_dirsize/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/pre_recurse_dirsize/#uses) | Source: [wp-includes/functions.php:8987](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L8987-L8987) * function[clean_dirsize_cache()](https://developer.wordpress.org/reference/functions/clean_dirsize_cache/) * Cleans directory size cache used by recurse_dirsize(). * Used by [3 functions](https://developer.wordpress.org/reference/functions/clean_dirsize_cache/#used-by) | Uses [6 functions](https://developer.wordpress.org/reference/functions/clean_dirsize_cache/#uses) | Source: [wp-includes/functions.php:9044](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L9044-L9090) * function[_wp_array_get()](https://developer.wordpress.org/reference/functions/_wp_array_get/) * Accesses an array in depth based on a path of keys. * Used by [32 functions](https://developer.wordpress.org/reference/functions/_wp_array_get/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/_wp_array_get/#uses) | Source: [wp-includes/functions.php:5169](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5169-L5208) * hook[pre_wp_unique_filename_file_list](https://developer.wordpress.org/reference/hooks/pre_wp_unique_filename_file_list/) * Filters the file list used for calculating a unique filename for a newly added file. * Used by [1 function](https://developer.wordpress.org/reference/hooks/pre_wp_unique_filename_file_list/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/pre_wp_unique_filename_file_list/#uses) | Source: [wp-includes/functions.php:2708](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L2708-L2708) * function[_wp_check_existing_file_names()](https://developer.wordpress.org/reference/functions/_wp_check_existing_file_names/) * Helper function to check if a file name could match an existing image sub-size file name. * Used by [2 functions](https://developer.wordpress.org/reference/functions/_wp_check_existing_file_names/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/_wp_check_existing_file_names/#uses) | Source: [wp-includes/functions.php:2870](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L2870-L2892) * function[do_favicon()](https://developer.wordpress.org/reference/functions/do_favicon/) * Displays the favicon.ico file content. * Used by [0 functions](https://developer.wordpress.org/reference/functions/do_favicon/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/do_favicon/#uses) | Source: [wp-includes/functions.php:1749](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L1749-L1759) * hook[do_faviconico](https://developer.wordpress.org/reference/hooks/do_faviconico/) * Fires when serving the favicon.ico file. * Used by [1 function](https://developer.wordpress.org/reference/hooks/do_faviconico/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/do_faviconico/#uses) | Source: [wp-includes/functions.php:1755](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L1755-L1755) * function[wp_fuzzy_number_match()](https://developer.wordpress.org/reference/functions/wp_fuzzy_number_match/) * Checks if two numbers are nearly the same. * Used by [2 functions](https://developer.wordpress.org/reference/functions/wp_fuzzy_number_match/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/wp_fuzzy_number_match/#uses) | Source: [wp-includes/functions.php:9172](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L9172-L9174) * function[current_datetime()](https://developer.wordpress.org/reference/functions/current_datetime/) * Retrieves the current time as an object using the site’s timezone. * Used by [1 function](https://developer.wordpress.org/reference/functions/current_datetime/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/current_datetime/#uses) | Source: [wp-includes/functions.php:101](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L101-L103) * function[wp_timezone_string()](https://developer.wordpress.org/reference/functions/wp_timezone_string/) * Retrieves the timezone of the site as a string. * Used by [2 functions](https://developer.wordpress.org/reference/functions/wp_timezone_string/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_timezone_string/#uses) | Source: [wp-includes/functions.php:124](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L124-L141) * function[wp_timezone()](https://developer.wordpress.org/reference/functions/wp_timezone/) * Retrieves the timezone of the site as a `DateTimeZone` object. * Used by [10 functions](https://developer.wordpress.org/reference/functions/wp_timezone/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_timezone/#uses) | Source: [wp-includes/functions.php:152](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L152-L154) * function[wp_date()](https://developer.wordpress.org/reference/functions/wp_date/) * Retrieves the date, in localized format. * Used by [6 functions](https://developer.wordpress.org/reference/functions/wp_date/#used-by) | Uses [8 functions](https://developer.wordpress.org/reference/functions/wp_date/#uses) | Source: [wp-includes/functions.php:243](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L243-L321) * hook[wp_date](https://developer.wordpress.org/reference/hooks/wp_date/) * Filters the date formatted based on the locale. * Used by [1 function](https://developer.wordpress.org/reference/hooks/wp_date/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/wp_date/#uses) | Source: [wp-includes/functions.php:318](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L318-L318) * function[is_wp_version_compatible()](https://developer.wordpress.org/reference/functions/is_wp_version_compatible/) * Checks compatibility with the current WordPress version. * Used by [16 functions](https://developer.wordpress.org/reference/functions/is_wp_version_compatible/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/is_wp_version_compatible/#uses) | Source: [wp-includes/functions.php:9123](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L9123-L9146) * function[is_php_version_compatible()](https://developer.wordpress.org/reference/functions/is_php_version_compatible/) * Checks compatibility with the current PHP version. * Used by [18 functions](https://developer.wordpress.org/reference/functions/is_php_version_compatible/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/is_php_version_compatible/#uses) | Source: [wp-includes/functions.php:9156](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L9156-L9158) * function[wp_get_update_php_annotation()](https://developer.wordpress.org/reference/functions/wp_get_update_php_annotation/) * Returns the default annotation for the web hosting altering the “Update PHP” page URL. * Used by [6 functions](https://developer.wordpress.org/reference/functions/wp_get_update_php_annotation/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/wp_get_update_php_annotation/#uses) | Source: [wp-includes/functions.php:8728](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L8728-L8743) * function[_jsonp_wp_die_handler()](https://developer.wordpress.org/reference/functions/_jsonp_wp_die_handler/) * Kills WordPress execution and displays JSONP response with an error message. * Used by [0 functions](https://developer.wordpress.org/reference/functions/_jsonp_wp_die_handler/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/_jsonp_wp_die_handler/#uses) | Source: [wp-includes/functions.php:4196](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4196-L4228) * function[_xml_wp_die_handler()](https://developer.wordpress.org/reference/functions/_xml_wp_die_handler/) * Kills WordPress execution and displays XML response with an error message. * Used by [0 functions](https://developer.wordpress.org/reference/functions/_xml_wp_die_handler/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/_xml_wp_die_handler/#uses) | Source: [wp-includes/functions.php:4276](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4276-L4306) * hook[wp_die_jsonp_handler](https://developer.wordpress.org/reference/hooks/wp_die_jsonp_handler/) * Filters the callback for killing WordPress execution for JSONP REST requests. * Used by [1 function](https://developer.wordpress.org/reference/hooks/wp_die_jsonp_handler/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/wp_die_jsonp_handler/#uses) | Source: [wp-includes/functions.php:3856](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L3856-L3856) * hook[wp_die_xml_handler](https://developer.wordpress.org/reference/hooks/wp_die_xml_handler/) * Filters the callback for killing WordPress execution for XML requests. * Used by [1 function](https://developer.wordpress.org/reference/hooks/wp_die_xml_handler/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/wp_die_xml_handler/#uses) | Source: [wp-includes/functions.php:3878](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L3878-L3878) [Previous Page](https://developer.wordpress.org/reference/files/wp-includes/functions.php/?output_format=md) [1](https://developer.wordpress.org/reference/files/wp-includes/functions.php/?output_format=md) 2 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