+
+/**
+ * Permanently deletes posts, pages, attachments, and comments which have been in the trash for EMPTY_TRASH_DAYS.
+ *
+ * @since 2.9.0
+ */
+function wp_scheduled_delete() {
+ global $wpdb;
+
+ $delete_timestamp = time() - (60*60*24*EMPTY_TRASH_DAYS);
+
+ $posts_to_delete = $wpdb->get_results($wpdb->prepare("SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_wp_trash_meta_time' AND meta_value < '%d'", $delete_timestamp), ARRAY_A);
+
+ foreach ( (array) $posts_to_delete as $post ) {
+ $post_id = (int) $post['post_id'];
+ if ( !$post_id )
+ continue;
+
+ $del_post = get_post($post_id);
+
+ if ( !$del_post || 'trash' != $del_post->post_status ) {
+ delete_post_meta($post_id, '_wp_trash_meta_status');
+ delete_post_meta($post_id, '_wp_trash_meta_time');
+ } else {
+ wp_delete_post($post_id);
+ }
+ }
+
+ $comments_to_delete = $wpdb->get_results($wpdb->prepare("SELECT comment_id FROM $wpdb->commentmeta WHERE meta_key = '_wp_trash_meta_time' AND meta_value < '%d'", $delete_timestamp), ARRAY_A);
+
+ foreach ( (array) $comments_to_delete as $comment ) {
+ $comment_id = (int) $comment['comment_id'];
+ if ( !$comment_id )
+ continue;
+
+ $del_comment = get_comment($comment_id);
+
+ if ( !$del_comment || 'trash' != $del_comment->comment_approved ) {
+ delete_comment_meta($comment_id, '_wp_trash_meta_time');
+ delete_comment_meta($comment_id, '_wp_trash_meta_status');
+ } else {
+ wp_delete_comment($comment_id);
+ }
+ }
+}
+
+/**
+ * Retrieve metadata from a file.
+ *
+ * Searches for metadata in the first 8kiB of a file, such as a plugin or theme.
+ * Each piece of metadata must be on its own line. Fields can not span multple
+ * lines, the value will get cut at the end of the first line.
+ *
+ * If the file data is not within that first 8kiB, then the author should correct
+ * their plugin file and move the data headers to the top.
+ *
+ * @see http://codex.wordpress.org/File_Header
+ *
+ * @since 2.9.0
+ * @param string $file Path to the file
+ * @param array $default_headers List of headers, in the format array('HeaderKey' => 'Header Name')
+ * @param string $context If specified adds filter hook "extra_{$context}_headers"
+ */
+function get_file_data( $file, $default_headers, $context = '' ) {
+ // We don't need to write to the file, so just open for reading.
+ $fp = fopen( $file, 'r' );
+
+ // Pull only the first 8kiB of the file in.
+ $file_data = fread( $fp, 8192 );
+
+ // PHP will close file handle, but we are good citizens.
+ fclose( $fp );
+
+ if ( $context != '' ) {
+ $extra_headers = apply_filters( "extra_{$context}_headers", array() );
+
+ $extra_headers = array_flip( $extra_headers );
+ foreach( $extra_headers as $key=>$value ) {
+ $extra_headers[$key] = $key;
+ }
+ $all_headers = array_merge( $extra_headers, (array) $default_headers );
+ } else {
+ $all_headers = $default_headers;
+ }
+
+ foreach ( $all_headers as $field => $regex ) {
+ preg_match( '/^[ \t\/*#@]*' . preg_quote( $regex, '/' ) . ':(.*)$/mi', $file_data, ${$field});
+ if ( !empty( ${$field} ) )
+ ${$field} = _cleanup_header_comment( ${$field}[1] );
+ else
+ ${$field} = '';
+ }
+
+ $file_data = compact( array_keys( $all_headers ) );
+
+ return $file_data;
+}
+
+/**
+ * Used internally to tidy up the search terms
+ *
+ * @access private
+ * @since 2.9.0
+ *
+ * @param string $t
+ * @return string
+ */
+function _search_terms_tidy($t) {
+ return trim($t, "\"'\n\r ");
+}
+
+/**
+ * Returns true
+ *
+ * Useful for returning true to filters easily
+ *
+ * @since 3.0.0
+ * @see __return_false()
+ * @return bool true
+ */
+function __return_true() {
+ return true;
+}
+
+/**
+ * Returns false
+ *
+ * Useful for returning false to filters easily
+ *
+ * @since 3.0.0
+ * @see __return_true()
+ * @return bool false
+ */
+function __return_false() {
+ return false;
+}
+
+/**
+ * Returns 0
+ *
+ * Useful for returning 0 to filters easily
+ *
+ * @since 3.0.0
+ * @see __return_zero()
+ * @return int 0
+ */
+function __return_zero() {
+ return 0;
+}
+
+/**
+ * Returns an empty array
+ *
+ * Useful for returning an empty array to filters easily
+ *
+ * @since 3.0.0
+ * @see __return_zero()
+ * @return array Empty array
+ */
+function __return_empty_array() {
+ return array();
+}
+
+/**
+ * Send a HTTP header to disable content type sniffing in browsers which support it.
+ *
+ * @link http://blogs.msdn.com/ie/archive/2008/07/02/ie8-security-part-v-comprehensive-protection.aspx
+ * @link http://src.chromium.org/viewvc/chrome?view=rev&revision=6985
+ *
+ * @since 3.0.0
+ * @return none
+ */
+function send_nosniff_header() {
+ @header( 'X-Content-Type-Options: nosniff' );
+}
+
+/**
+ * Returns a MySQL expression for selecting the week number based on the start_of_week option.
+ *
+ * @internal
+ * @since 3.0.0
+ * @param string $column
+ * @return string
+ */
+function _wp_mysql_week( $column ) {
+ switch ( $start_of_week = (int) get_option( 'start_of_week' ) ) {
+ default :
+ case 0 :
+ return "WEEK( $column, 0 )";
+ case 1 :
+ return "WEEK( $column, 1 )";
+ case 2 :
+ case 3 :
+ case 4 :
+ case 5 :
+ case 6 :
+ return "WEEK( DATE_SUB( $column, INTERVAL $start_of_week DAY ), 0 )";
+ }
+}
+
+/**
+ * Finds hierarchy loops using a callback function that maps object IDs to parent IDs.
+ *
+ * @since 3.1.0
+ * @access private
+ *
+ * @param callback $callback function that accepts ( ID, $callback_args ) and outputs parent_ID
+ * @param int $start The ID to start the loop check at
+ * @param int $start_parent the parent_ID of $start to use instead of calling $callback( $start ). Use null to always use $callback
+ * @param array $callback_args optional additional arguments to send to $callback
+ * @return array IDs of all members of loop
+ */
+function wp_find_hierarchy_loop( $callback, $start, $start_parent, $callback_args = array() ) {
+ $override = is_null( $start_parent ) ? array() : array( $start => $start_parent );
+
+ if ( !$arbitrary_loop_member = wp_find_hierarchy_loop_tortoise_hare( $callback, $start, $override, $callback_args ) )
+ return array();
+
+ return wp_find_hierarchy_loop_tortoise_hare( $callback, $arbitrary_loop_member, $override, $callback_args, true );
+}
+
+/**
+ * Uses the "The Tortoise and the Hare" algorithm to detect loops.
+ *
+ * For every step of the algorithm, the hare takes two steps and the tortoise one.
+ * If the hare ever laps the tortoise, there must be a loop.
+ *
+ * @since 3.1.0
+ * @access private
+ *
+ * @param callback $callback function that accupts ( ID, callback_arg, ... ) and outputs parent_ID
+ * @param int $start The ID to start the loop check at
+ * @param array $override an array of ( ID => parent_ID, ... ) to use instead of $callback
+ * @param array $callback_args optional additional arguments to send to $callback
+ * @param bool $_return_loop Return loop members or just detect presence of loop?
+ * Only set to true if you already know the given $start is part of a loop
+ * (otherwise the returned array might include branches)
+ * @return mixed scalar ID of some arbitrary member of the loop, or array of IDs of all members of loop if $_return_loop
+ */
+function wp_find_hierarchy_loop_tortoise_hare( $callback, $start, $override = array(), $callback_args = array(), $_return_loop = false ) {
+ $tortoise = $hare = $evanescent_hare = $start;
+ $return = array();
+
+ // Set evanescent_hare to one past hare
+ // Increment hare two steps
+ while (
+ $tortoise
+ &&
+ ( $evanescent_hare = isset( $override[$hare] ) ? $override[$hare] : call_user_func_array( $callback, array_merge( array( $hare ), $callback_args ) ) )
+ &&
+ ( $hare = isset( $override[$evanescent_hare] ) ? $override[$evanescent_hare] : call_user_func_array( $callback, array_merge( array( $evanescent_hare ), $callback_args ) ) )
+ ) {
+ if ( $_return_loop )
+ $return[$tortoise] = $return[$evanescent_hare] = $return[$hare] = true;
+
+ // tortoise got lapped - must be a loop
+ if ( $tortoise == $evanescent_hare || $tortoise == $hare )
+ return $_return_loop ? $return : $tortoise;
+
+ // Increment tortoise by one step
+ $tortoise = isset( $override[$tortoise] ) ? $override[$tortoise] : call_user_func_array( $callback, array_merge( array( $tortoise ), $callback_args ) );
+ }
+
+ return false;
+}
+