Title: wp-includes/functions.php | Page 7 of 10 | Developer.WordPress.org --- # File: wp-includes/functions.php * function[is_lighttpd_before_150()](https://developer.wordpress.org/reference/functions/is_lighttpd_before_150/) * Determines whether the server is running an earlier than 1.5.0 version of lighttpd. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_lighttpd_before_150/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/is_lighttpd_before_150/#uses) | Source: [wp-includes/functions.php:6270](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L6270-L6275) * function[apache_mod_loaded()](https://developer.wordpress.org/reference/functions/apache_mod_loaded/) * Determines whether the specified module exist in the Apache config. * Used by [2 functions](https://developer.wordpress.org/reference/functions/apache_mod_loaded/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/apache_mod_loaded/#uses) | Source: [wp-includes/functions.php:6288](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L6288-L6319) * function[iis7_supports_permalinks()](https://developer.wordpress.org/reference/functions/iis7_supports_permalinks/) * Checks if IIS 7+ supports pretty permalinks. * Used by [4 functions](https://developer.wordpress.org/reference/functions/iis7_supports_permalinks/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/iis7_supports_permalinks/#uses) | Source: [wp-includes/functions.php:6330](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L6330-L6355) * hook[iis7_supports_permalinks](https://developer.wordpress.org/reference/hooks/iis7_supports_permalinks/) * Filters whether IIS 7+ supports pretty permalinks. * Used by [1 function](https://developer.wordpress.org/reference/hooks/iis7_supports_permalinks/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/iis7_supports_permalinks/#uses) | Source: [wp-includes/functions.php:6354](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L6354-L6354) * function[_deprecated_function()](https://developer.wordpress.org/reference/functions/_deprecated_function/) * Marks a function as deprecated and inform when it has been used. * Used by [425 functions](https://developer.wordpress.org/reference/functions/_deprecated_function/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/_deprecated_function/#uses) | Source: [wp-includes/functions.php:5643](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5643-L5700) * function[validate_file()](https://developer.wordpress.org/reference/functions/validate_file/) * Validates a file name and path against an allowed set of rules. * Used by [14 functions](https://developer.wordpress.org/reference/functions/validate_file/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/validate_file/#uses) | Source: [wp-includes/functions.php:6372](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L6372-L6408) * hook[deprecated_function_run](https://developer.wordpress.org/reference/hooks/deprecated_function_run/) * Fires when a deprecated function is called. * Used by [1 function](https://developer.wordpress.org/reference/hooks/deprecated_function_run/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/deprecated_function_run/#uses) | Source: [wp-includes/functions.php:5654](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5654-L5654) * function[_config_wp_siteurl()](https://developer.wordpress.org/reference/functions/_config_wp_siteurl/) * Retrieves the WordPress site URL. * Used by [0 functions](https://developer.wordpress.org/reference/functions/_config_wp_siteurl/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/_config_wp_siteurl/#uses) | Source: [wp-includes/functions.php:4797](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4797-L4802) * function[_mce_set_direction()](https://developer.wordpress.org/reference/functions/_mce_set_direction/) * Sets the localized direction for MCE plugin. * Used by [0 functions](https://developer.wordpress.org/reference/functions/_mce_set_direction/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/_mce_set_direction/#uses) | Source: [wp-includes/functions.php:4831](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4831-L4846) * function[smilies_init()](https://developer.wordpress.org/reference/functions/smilies_init/) * Converts smiley code to the icon graphic file equivalent. * Used by [0 functions](https://developer.wordpress.org/reference/functions/smilies_init/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/smilies_init/#uses) | Source: [wp-includes/functions.php:4888](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4888-L4996) * function[wp_parse_args()](https://developer.wordpress.org/reference/functions/wp_parse_args/) * Merges user defined arguments into defaults array. * Used by [214 functions](https://developer.wordpress.org/reference/functions/wp_parse_args/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_parse_args/#uses) | Source: [wp-includes/functions.php:5012](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5012-L5025) * function[wp_parse_id_list()](https://developer.wordpress.org/reference/functions/wp_parse_id_list/) * Cleans up an array, comma- or space-separated list of IDs. * Used by [17 functions](https://developer.wordpress.org/reference/functions/wp_parse_id_list/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_parse_id_list/#uses) | Source: [wp-includes/functions.php:5065](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5065-L5069) * function[wp_array_slice_assoc()](https://developer.wordpress.org/reference/functions/wp_array_slice_assoc/) * Extracts a slice of an array, given a list of keys. * Used by [27 functions](https://developer.wordpress.org/reference/functions/wp_array_slice_assoc/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/wp_array_slice_assoc/#uses) | Source: [wp-includes/functions.php:5109](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5109-L5119) * function[wp_filter_object_list()](https://developer.wordpress.org/reference/functions/wp_filter_object_list/) * Filters a list of objects, based on a set of key => value arguments. * Used by [8 functions](https://developer.wordpress.org/reference/functions/wp_filter_object_list/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_filter_object_list/#uses) | Source: [wp-includes/functions.php:5419](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5419-L5433) * function[wp_list_filter()](https://developer.wordpress.org/reference/functions/wp_list_filter/) * Filters a list of objects, based on a set of key => value arguments. * Used by [15 functions](https://developer.wordpress.org/reference/functions/wp_list_filter/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_list_filter/#uses) | Source: [wp-includes/functions.php:5461](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5461-L5463) * function[wp_list_pluck()](https://developer.wordpress.org/reference/functions/wp_list_pluck/) * Plucks a certain field out of each object or array in an array. * Used by [44 functions](https://developer.wordpress.org/reference/functions/wp_list_pluck/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_list_pluck/#uses) | Source: [wp-includes/functions.php:5483](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5483-L5491) * function[wp_maybe_load_widgets()](https://developer.wordpress.org/reference/functions/wp_maybe_load_widgets/) * Determines if Widgets library should be loaded. * Used by [0 functions](https://developer.wordpress.org/reference/functions/wp_maybe_load_widgets/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/wp_maybe_load_widgets/#uses) | Source: [wp-includes/functions.php:5525](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5525-L5544) * hook[load_default_widgets](https://developer.wordpress.org/reference/hooks/load_default_widgets/) * Filters whether to load the Widgets library. * Used by [1 function](https://developer.wordpress.org/reference/hooks/load_default_widgets/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/load_default_widgets/#uses) | Source: [wp-includes/functions.php:5537](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5537-L5537) * function[_scalar_wp_die_handler()](https://developer.wordpress.org/reference/functions/_scalar_wp_die_handler/) * Kills WordPress execution and displays an error message. * Used by [0 functions](https://developer.wordpress.org/reference/functions/_scalar_wp_die_handler/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/_scalar_wp_die_handler/#uses) | Source: [wp-includes/functions.php:4322](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4322-L4335) * function[wp_widgets_add_menu()](https://developer.wordpress.org/reference/functions/wp_widgets_add_menu/) * Appends the Widgets menu to the themes main menu. * Used by [0 functions](https://developer.wordpress.org/reference/functions/wp_widgets_add_menu/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/wp_widgets_add_menu/#uses) | Source: [wp-includes/functions.php:5554](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5554-L5569) * function[wp_send_json()](https://developer.wordpress.org/reference/functions/wp_send_json/) * Sends a JSON response back to an Ajax request. * Used by [4 functions](https://developer.wordpress.org/reference/functions/wp_send_json/#used-by) | Uses [8 functions](https://developer.wordpress.org/reference/functions/wp_send_json/#uses) | Source: [wp-includes/functions.php:4587](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4587-L4621) * function[wp_ob_end_flush_all()](https://developer.wordpress.org/reference/functions/wp_ob_end_flush_all/) * Flushes all output buffers for PHP 5.2. * Used by [3 functions](https://developer.wordpress.org/reference/functions/wp_ob_end_flush_all/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/wp_ob_end_flush_all/#uses) | Source: [wp-includes/functions.php:5578](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5578-L5583) * function[wp_send_json_success()](https://developer.wordpress.org/reference/functions/wp_send_json_success/) * Sends a JSON response back to an Ajax request, indicating success. * Used by [62 functions](https://developer.wordpress.org/reference/functions/wp_send_json_success/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/wp_send_json_success/#uses) | Source: [wp-includes/functions.php:4635](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4635-L4643) * function[dead_db()](https://developer.wordpress.org/reference/functions/dead_db/) * Loads custom DB error or display WordPress DB error. * Used by [4 functions](https://developer.wordpress.org/reference/functions/dead_db/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/dead_db/#uses) | Source: [wp-includes/functions.php:5605](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L5605-L5623) * function[wp_send_json_error()](https://developer.wordpress.org/reference/functions/wp_send_json_error/) * Sends a JSON response back to an Ajax request, indicating failure. * Used by [63 functions](https://developer.wordpress.org/reference/functions/wp_send_json_error/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/wp_send_json_error/#uses) | Source: [wp-includes/functions.php:4663](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4663-L4685) * function[_config_wp_home()](https://developer.wordpress.org/reference/functions/_config_wp_home/) * Retrieves the WordPress home page URL. * Used by [0 functions](https://developer.wordpress.org/reference/functions/_config_wp_home/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/_config_wp_home/#uses) | Source: [wp-includes/functions.php:4775](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L4775-L4780) * hook[mime_types](https://developer.wordpress.org/reference/hooks/mime_types/) * Filters the list of mime types and file extensions. * Used by [1 function](https://developer.wordpress.org/reference/hooks/mime_types/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/mime_types/#uses) | Source: [wp-includes/functions.php:3483](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L3483-L3597) * function[get_allowed_mime_types()](https://developer.wordpress.org/reference/functions/get_allowed_mime_types/) * Retrieves the list of allowed mime types and file extensions. * Used by [10 functions](https://developer.wordpress.org/reference/functions/get_allowed_mime_types/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/get_allowed_mime_types/#uses) | Source: [wp-includes/functions.php:3693](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L3693-L3714) * hook[upload_mimes](https://developer.wordpress.org/reference/hooks/upload_mimes/) * Filters the list of allowed mime types and file extensions. * Used by [1 function](https://developer.wordpress.org/reference/hooks/upload_mimes/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/hooks/upload_mimes/#uses) | Source: [wp-includes/functions.php:3713](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L3713-L3713) * function[wp_nonce_ays()](https://developer.wordpress.org/reference/functions/wp_nonce_ays/) * Displays “Are You Sure” message to confirm the action being taken. * Used by [1 function](https://developer.wordpress.org/reference/functions/wp_nonce_ays/#used-by) | Uses [9 functions](https://developer.wordpress.org/reference/functions/wp_nonce_ays/#uses) | Source: [wp-includes/functions.php:3727](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/functions.php#L3727-L3765) [Previous Page](https://developer.wordpress.org/reference/files/wp-includes/functions.php/page/6/?output_format=md) [1](https://developer.wordpress.org/reference/files/wp-includes/functions.php/?output_format=md)… 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