/wp-includes/functions.php

Large files files are truncated, but you can click here to view the full file

<?php
/**
 * Main WordPress API
 *
 * @package WordPress
 */

require ABSPATH . WPINC . '/option.php';

/**
 * Convert given MySQL date string into a different format.
 *
 * `$format` should be a PHP date format string.
 * 'U' and 'G' formats will return a sum of timestamp with timezone offset.
 * `$date` is expected to be local time in MySQL format (`Y-m-d H:i:s`).
 *
 * Historically UTC time could be passed to the function to produce Unix timestamp.
 *
 * If `$translate` is true then the given date and format string will
 * be passed to `wp_date()` for translation.
 *
 * @since 0.71
 *
 * @param string $format    Format of the date to return.
 * @param string $date      Date string to convert.
 * @param bool   $translate Whether the return date should be translated. Default true.
 * @return string|int|false Formatted date string or sum of Unix timestamp and timezone offset.
 *                          False on failure.
 */
function mysql2date( $format, $date, $translate = true ) {
	if ( empty( $date ) ) {
		return false;
	}

	$datetime = date_create( $date, wp_timezone() );

	if ( false === $datetime ) {
		return false;
	}

	// Returns a sum of timestamp with timezone offset. Ideally should never be used.
	if ( 'G' === $format || 'U' === $format ) {
		return $datetime->getTimestamp() + $datetime->getOffset();
	}

	if ( $translate ) {
		return wp_date( $format, $datetime->getTimestamp() );
	}

	return $datetime->format( $format );
}

/**
 * Retrieves the current time based on specified type.
 *
 * The 'mysql' type will return the time in the format for MySQL DATETIME field.
 * The 'timestamp' type will return the current timestamp or a sum of timestamp
 * and timezone offset, depending on `$gmt`.
 * Other strings will be interpreted as PHP date formats (e.g. 'Y-m-d').
 *
 * If $gmt is set to either '1' or 'true', then both types will use GMT time.
 * if $gmt is false, the output is adjusted with the GMT offset in the WordPress option.
 *
 * @since 1.0.0
 *
 * @param string   $type Type of time to retrieve. Accepts 'mysql', 'timestamp',
 *                       or PHP date format string (e.g. 'Y-m-d').
 * @param int|bool $gmt  Optional. Whether to use GMT timezone. Default false.
 * @return int|string Integer if $type is 'timestamp', string otherwise.
 */
function current_time( $type, $gmt = 0 ) {
	// Don't use non-GMT timestamp, unless you know the difference and really need to.
	if ( 'timestamp' === $type || 'U' === $type ) {
		return $gmt ? time() : time() + (int) ( get_option( 'gmt_offset' ) * HOUR_IN_SECONDS );
	}

	if ( 'mysql' === $type ) {
		$type = 'Y-m-d H:i:s';
	}

	$timezone = $gmt ? new DateTimeZone( 'UTC' ) : wp_timezone();
	$datetime = new DateTime( 'now', $timezone );

	return $datetime->format( $type );
}

/**
 * Retrieves the current time as an object with the timezone from settings.
 *
 * @since 5.3.0
 *
 * @return DateTimeImmutable Date and time object.
 */
function current_datetime() {
	return new DateTimeImmutable( 'now', wp_timezone() );
}

/**
 * Retrieves the timezone from site settings as a string.
 *
 * Uses the `timezone_string` option to get a proper timezone if available,
 * otherwise falls back to an offset.
 *
 * @since 5.3.0
 *
 * @return string PHP timezone string or a ±HH:MM offset.
 */
function wp_timezone_string() {
	$timezone_string = get_option( 'timezone_string' );

	if ( $timezone_string ) {
		return $timezone_string;
	}

	$offset  = (float) get_option( 'gmt_offset' );
	$hours   = (int) $offset;
	$minutes = ( $offset - $hours );

	$sign      = ( $offset < 0 ) ? '-' : '+';
	$abs_hour  = abs( $hours );
	$abs_mins  = abs( $minutes * 60 );
	$tz_offset = sprintf( '%s%02d:%02d', $sign, $abs_hour, $abs_mins );

	return $tz_offset;
}

/**
 * Retrieves the timezone from site settings as a `DateTimeZone` object.
 *
 * Timezone can be based on a PHP timezone string or a ±HH:MM offset.
 *
 * @since 5.3.0
 *
 * @return DateTimeZone Timezone object.
 */
function wp_timezone() {
	return new DateTimeZone( wp_timezone_string() );
}

/**
 * Retrieves the date in localized format, based on a sum of Unix timestamp and
 * timezone offset in seconds.
 *
 * If the locale specifies the locale month and weekday, then the locale will
 * take over the format for the date. If it isn't, then the date format string
 * will be used instead.
 *
 * Note that due to the way WP typically generates a sum of timestamp and offset
 * with `strtotime()`, it implies offset added at a _current_ time, not at the time
 * the timestamp represents. Storing such timestamps or calculating them differently
 * will lead to invalid output.
 *
 * @since 0.71
 * @since 5.3.0 Converted into a wrapper for wp_date().
 *
 * @global WP_Locale $wp_locale WordPress date and time locale object.
 *
 * @param string   $format                Format to display the date.
 * @param int|bool $timestamp_with_offset Optional. A sum of Unix timestamp and timezone offset
 *                                        in seconds. Default false.
 * @param bool     $gmt                   Optional. Whether to use GMT timezone. Only applies
 *                                        if timestamp is not provided. Default false.
 * @return string The date, translated if locale specifies it.
 */
function date_i18n( $format, $timestamp_with_offset = false, $gmt = false ) {
	$timestamp = $timestamp_with_offset;

	// If timestamp is omitted it should be current time (summed with offset, unless `$gmt` is true).
	if ( ! is_numeric( $timestamp ) ) {
		$timestamp = current_time( 'timestamp', $gmt );
	}

	/*
	 * This is a legacy implementation quirk that the returned timestamp is also with offset.
	 * Ideally this function should never be used to produce a timestamp.
	 */
	if ( 'U' === $format ) {
		$date = $timestamp;
	} elseif ( $gmt && false === $timestamp_with_offset ) { // Current time in UTC.
		$date = wp_date( $format, null, new DateTimeZone( 'UTC' ) );
	} elseif ( false === $timestamp_with_offset ) { // Current time in site's timezone.
		$date = wp_date( $format );
	} else {
		/*
		 * Timestamp with offset is typically produced by a UTC `strtotime()` call on an input without timezone.
		 * This is the best attempt to reverse that operation into a local time to use.
		 */
		$local_time = gmdate( 'Y-m-d H:i:s', $timestamp );
		$timezone   = wp_timezone();
		$datetime   = date_create( $local_time, $timezone );
		$date       = wp_date( $format, $datetime->getTimestamp(), $timezone );
	}

	/**
	 * Filters the date formatted based on the locale.
	 *
	 * @since 2.8.0
	 *
	 * @param string $date      Formatted date string.
	 * @param string $format    Format to display the date.
	 * @param int    $timestamp A sum of Unix timestamp and timezone offset in seconds.
	 *                          Might be without offset if input omitted timestamp but requested GMT.
	 * @param bool   $gmt       Whether to use GMT timezone. Only applies if timestamp was not provided.
	 *                          Default false.
	 */
	$date = apply_filters( 'date_i18n', $date, $format, $timestamp, $gmt );

	return $date;
}

/**
 * Retrieves the date, in localized format.
 *
 * This is a newer function, intended to replace `date_i18n()` without legacy quirks in it.
 *
 * Note that, unlike `date_i18n()`, this function accepts a true Unix timestamp, not summed
 * with timezone offset.
 *
 * @since 5.3.0
 *
 * @param string       $format    PHP date format.
 * @param int          $timestamp Optional. Unix timestamp. Defaults to current time.
 * @param DateTimeZone $timezone  Optional. Timezone to output result in. Defaults to timezone
 *                                from site settings.
 * @return string|false The date, translated if locale specifies it. False on invalid timestamp input.
 */
function wp_date( $format, $timestamp = null, $timezone = null ) {
	global $wp_locale;

	if ( null === $timestamp ) {
		$timestamp = time();
	} elseif ( ! is_numeric( $timestamp ) ) {
		return false;
	}

	if ( ! $timezone ) {
		$timezone = wp_timezone();
	}

	$datetime = date_create( '@' . $timestamp );
	$datetime->setTimezone( $timezone );

	if ( empty( $wp_locale->month ) || empty( $wp_locale->weekday ) ) {
		$date = $datetime->format( $format );
	} else {
		// We need to unpack shorthand `r` format because it has parts that might be localized.
		$format = preg_replace( '/(?<!\\\\)r/', DATE_RFC2822, $format );

		$new_format    = '';
		$format_length = strlen( $format );
		$month         = $wp_locale->get_month( $datetime->format( 'm' ) );
		$weekday       = $wp_locale->get_weekday( $datetime->format( 'w' ) );

		for ( $i = 0; $i < $format_length; $i ++ ) {
			switch ( $format[ $i ] ) {
				case 'D':
					$new_format .= addcslashes( $wp_locale->get_weekday_abbrev( $weekday ), '\\A..Za..z' );
					break;
				case 'F':
					$new_format .= addcslashes( $month, '\\A..Za..z' );
					break;
				case 'l':
					$new_format .= addcslashes( $weekday, '\\A..Za..z' );
					break;
				case 'M':
					$new_format .= addcslashes( $wp_locale->get_month_abbrev( $month ), '\\A..Za..z' );
					break;
				case 'a':
					$new_format .= addcslashes( $wp_locale->get_meridiem( $datetime->format( 'a' ) ), '\\A..Za..z' );
					break;
				case 'A':
					$new_format .= addcslashes( $wp_locale->get_meridiem( $datetime->format( 'A' ) ), '\\A..Za..z' );
					break;
				case '\\':
					$new_format .= $format[ $i ];

					// If character follows a slash, we add it without translating.
					if ( $i < $format_length ) {
						$new_format .= $format[ ++$i ];
					}
					break;
				default:
					$new_format .= $format[ $i ];
					break;
			}
		}

		$date = $datetime->format( $new_format );
		$date = wp_maybe_decline_date( $date, $format );
	}

	/**
	 * Filters the date formatted based on the locale.
	 *
	 * @since 5.3.0
	 *
	 * @param string       $date      Formatted date string.
	 * @param string       $format    Format to display the date.
	 * @param int          $timestamp Unix timestamp.
	 * @param DateTimeZone $timezone  Timezone.
	 *
	 */
	$date = apply_filters( 'wp_date', $date, $format, $timestamp, $timezone );

	return $date;
}

/**
 * Determines if the date should be declined.
 *
 * If the locale specifies that month names require a genitive case in certain
 * formats (like 'j F Y'), the month name will be replaced with a correct form.
 *
 * @since 4.4.0
 * @since 5.4.0 The `$format` parameter was added.
 *
 * @global WP_Locale $wp_locale WordPress date and time locale object.
 *
 * @param string $date   Formatted date string.
 * @param string $format Optional. Date format to check. Default empty string.
 * @return string The date, declined if locale specifies it.
 */
function wp_maybe_decline_date( $date, $format = '' ) {
	global $wp_locale;

	// i18n functions are not available in SHORTINIT mode.
	if ( ! function_exists( '_x' ) ) {
		return $date;
	}

	/*
	 * translators: If months in your language require a genitive case,
	 * translate this to 'on'. Do not translate into your own language.
	 */
	if ( 'on' === _x( 'off', 'decline months names: on or off' ) ) {

		$months          = $wp_locale->month;
		$months_genitive = $wp_locale->month_genitive;

		/*
		 * Match a format like 'j F Y' or 'j. F' (day of the month, followed by month name)
		 * and decline the month.
		 */
		if ( $format ) {
			$decline = preg_match( '#[dj]\.? F#', $format );
		} else {
			// If the format is not passed, try to guess it from the date string.
			$decline = preg_match( '#\b\d{1,2}\.? [^\d ]+\b#u', $date );
		}

		if ( $decline ) {
			foreach ( $months as $key => $month ) {
				$months[ $key ] = '# ' . preg_quote( $month, '#' ) . '\b#u';
			}

			foreach ( $months_genitive as $key => $month ) {
				$months_genitive[ $key ] = ' ' . $month;
			}

			$date = preg_replace( $months, $months_genitive, $date );
		}

		/*
		 * Match a format like 'F jS' or 'F j' (month name, followed by day with an optional ordinal suffix)
		 * and change it to declined 'j F'.
		 */
		if ( $format ) {
			$decline = preg_match( '#F [dj]#', $format );
		} else {
			// If the format is not passed, try to guess it from the date string.
			$decline = preg_match( '#\b[^\d ]+ \d{1,2}(st|nd|rd|th)?\b#u', trim( $date ) );
		}

		if ( $decline ) {
			foreach ( $months as $key => $month ) {
				$months[ $key ] = '#\b' . preg_quote( $month, '#' ) . ' (\d{1,2})(st|nd|rd|th)?([-–]\d{1,2})?(st|nd|rd|th)?\b#u';
			}

			foreach ( $months_genitive as $key => $month ) {
				$months_genitive[ $key ] = '$1$3 ' . $month;
			}

			$date = preg_replace( $months, $months_genitive, $date );
		}
	}

	// Used for locale-specific rules.
	$locale = get_locale();

	if ( 'ca' === $locale ) {
		// " de abril| de agost| de octubre..." -> " d'abril| d'agost| d'octubre..."
		$date = preg_replace( '# de ([ao])#i', " d'\\1", $date );
	}

	return $date;
}

/**
 * Convert float number to format based on the locale.
 *
 * @since 2.3.0
 *
 * @global WP_Locale $wp_locale WordPress date and time locale object.
 *
 * @param float $number   The number to convert based on locale.
 * @param int   $decimals Optional. Precision of the number of decimal places. Default 0.
 * @return string Converted number in string format.
 */
function number_format_i18n( $number, $decimals = 0 ) {
	global $wp_locale;

	if ( isset( $wp_locale ) ) {
		$formatted = number_format( $number, absint( $decimals ), $wp_locale->number_format['decimal_point'], $wp_locale->number_format['thousands_sep'] );
	} else {
		$formatted = number_format( $number, absint( $decimals ) );
	}

	/**
	 * Filters the number formatted based on the locale.
	 *
	 * @since 2.8.0
	 * @since 4.9.0 The `$number` and `$decimals` parameters were added.
	 *
	 * @param string $formatted Converted number in string format.
	 * @param float  $number    The number to convert based on locale.
	 * @param int    $decimals  Precision of the number of decimal places.
	 */
	return apply_filters( 'number_format_i18n', $formatted, $number, $decimals );
}

/**
 * Convert number of bytes largest unit bytes will fit into.
 *
 * It is easier to read 1 KB than 1024 bytes and 1 MB than 1048576 bytes. Converts
 * number of bytes to human readable number by taking the number of that unit
 * that the bytes will go into it. Supports TB value.
 *
 * Please note that integers in PHP are limited to 32 bits, unless they are on
 * 64 bit architecture, then they have 64 bit size. If you need to place the
 * larger size then what PHP integer type will hold, then use a string. It will
 * be converted to a double, which should always have 64 bit length.
 *
 * Technically the correct unit names for powers of 1024 are KiB, MiB etc.
 *
 * @since 2.3.0
 *
 * @param int|string $bytes    Number of bytes. Note max integer size for integers.
 * @param int        $decimals Optional. Precision of number of decimal places. Default 0.
 * @return string|false False on failure. Number string on success.
 */
function size_format( $bytes, $decimals = 0 ) {
	$quant = array(
		'TB' => TB_IN_BYTES,
		'GB' => GB_IN_BYTES,
		'MB' => MB_IN_BYTES,
		'KB' => KB_IN_BYTES,
		'B'  => 1,
	);

	if ( 0 === $bytes ) {
		return number_format_i18n( 0, $decimals ) . ' B';
	}

	foreach ( $quant as $unit => $mag ) {
		if ( doubleval( $bytes ) >= $mag ) {
			return number_format_i18n( $bytes / $mag, $decimals ) . ' ' . $unit;
		}
	}

	return false;
}

/**
 * Convert a duration to human readable format.
 *
 * @since 5.1.0
 *
 * @param string $duration Duration will be in string format (HH:ii:ss) OR (ii:ss),
 *                         with a possible prepended negative sign (-).
 * @return string|false A human readable duration string, false on failure.
 */
function human_readable_duration( $duration = '' ) {
	if ( ( empty( $duration ) || ! is_string( $duration ) ) ) {
		return false;
	}

	$duration = trim( $duration );

	// Remove prepended negative sign.
	if ( '-' === substr( $duration, 0, 1 ) ) {
		$duration = substr( $duration, 1 );
	}

	// Extract duration parts.
	$duration_parts = array_reverse( explode( ':', $duration ) );
	$duration_count = count( $duration_parts );

	$hour   = null;
	$minute = null;
	$second = null;

	if ( 3 === $duration_count ) {
		// Validate HH:ii:ss duration format.
		if ( ! ( (bool) preg_match( '/^([0-9]+):([0-5]?[0-9]):([0-5]?[0-9])$/', $duration ) ) ) {
			return false;
		}
		// Three parts: hours, minutes & seconds.
		list( $second, $minute, $hour ) = $duration_parts;
	} elseif ( 2 === $duration_count ) {
		// Validate ii:ss duration format.
		if ( ! ( (bool) preg_match( '/^([0-5]?[0-9]):([0-5]?[0-9])$/', $duration ) ) ) {
			return false;
		}
		// Two parts: minutes & seconds.
		list( $second, $minute ) = $duration_parts;
	} else {
		return false;
	}

	$human_readable_duration = array();

	// Add the hour part to the string.
	if ( is_numeric( $hour ) ) {
		/* translators: %s: Time duration in hour or hours. */
		$human_readable_duration[] = sprintf( _n( '%s hour', '%s hours', $hour ), (int) $hour );
	}

	// Add the minute part to the string.
	if ( is_numeric( $minute ) ) {
		/* translators: %s: Time duration in minute or minutes. */
		$human_readable_duration[] = sprintf( _n( '%s minute', '%s minutes', $minute ), (int) $minute );
	}

	// Add the second part to the string.
	if ( is_numeric( $second ) ) {
		/* translators: %s: Time duration in second or seconds. */
		$human_readable_duration[] = sprintf( _n( '%s second', '%s seconds', $second ), (int) $second );
	}

	return implode( ', ', $human_readable_duration );
}

/**
 * Get the week start and end from the datetime or date string from MySQL.
 *
 * @since 0.71
 *
 * @param string     $mysqlstring   Date or datetime field type from MySQL.
 * @param int|string $start_of_week Optional. Start of the week as an integer. Default empty string.
 * @return array Keys are 'start' and 'end'.
 */
function get_weekstartend( $mysqlstring, $start_of_week = '' ) {
	// MySQL string year.
	$my = substr( $mysqlstring, 0, 4 );

	// MySQL string month.
	$mm = substr( $mysqlstring, 8, 2 );

	// MySQL string day.
	$md = substr( $mysqlstring, 5, 2 );

	// The timestamp for MySQL string day.
	$day = mktime( 0, 0, 0, $md, $mm, $my );

	// The day of the week from the timestamp.
	$weekday = gmdate( 'w', $day );

	if ( ! is_numeric( $start_of_week ) ) {
		$start_of_week = get_option( 'start_of_week' );
	}

	if ( $weekday < $start_of_week ) {
		$weekday += 7;
	}

	// The most recent week start day on or before $day.
	$start = $day - DAY_IN_SECONDS * ( $weekday - $start_of_week );

	// $start + 1 week - 1 second.
	$end = $start + WEEK_IN_SECONDS - 1;
	return compact( 'start', 'end' );
}

/**
 * Serialize data, if needed.
 *
 * @since 2.0.5
 *
 * @param string|array|object $data Data that might be serialized.
 * @return mixed A scalar data.
 */
function maybe_serialize( $data ) {
	if ( is_array( $data ) || is_object( $data ) ) {
		return serialize( $data );
	}

	/*
	 * Double serialization is required for backward compatibility.
	 * See https://core.trac.wordpress.org/ticket/12930
	 * Also the world will end. See WP 3.6.1.
	 */
	if ( is_serialized( $data, false ) ) {
		return serialize( $data );
	}

	return $data;
}

/**
 * Unserialize data only if it was serialized.
 *
 * @since 2.0.0
 *
 * @param string $data Data that might be unserialized.
 * @return mixed Unserialized data can be any type.
 */
function maybe_unserialize( $data ) {
	if ( is_serialized( $data ) ) { // Don't attempt to unserialize data that wasn't serialized going in.
		return @unserialize( trim( $data ) );
	}

	return $data;
}

/**
 * Check value to find if it was serialized.
 *
 * If $data is not an string, then returned value will always be false.
 * Serialized data is always a string.
 *
 * @since 2.0.5
 *
 * @param string $data   Value to check to see if was serialized.
 * @param bool   $strict Optional. Whether to be strict about the end of the string. Default true.
 * @return bool False if not serialized and true if it was.
 */
function is_serialized( $data, $strict = true ) {
	// If it isn't a string, it isn't serialized.
	if ( ! is_string( $data ) ) {
		return false;
	}
	$data = trim( $data );
	if ( 'N;' == $data ) {
		return true;
	}
	if ( strlen( $data ) < 4 ) {
		return false;
	}
	if ( ':' !== $data[1] ) {
		return false;
	}
	if ( $strict ) {
		$lastc = substr( $data, -1 );
		if ( ';' !== $lastc && '}' !== $lastc ) {
			return false;
		}
	} else {
		$semicolon = strpos( $data, ';' );
		$brace     = strpos( $data, '}' );
		// Either ; or } must exist.
		if ( false === $semicolon && false === $brace ) {
			return false;
		}
		// But neither must be in the first X characters.
		if ( false !== $semicolon && $semicolon < 3 ) {
			return false;
		}
		if ( false !== $brace && $brace < 4 ) {
			return false;
		}
	}
	$token = $data[0];
	switch ( $token ) {
		case 's':
			if ( $strict ) {
				if ( '"' !== substr( $data, -2, 1 ) ) {
					return false;
				}
			} elseif ( false === strpos( $data, '"' ) ) {
				return false;
			}
			// Or else fall through.
		case 'a':
		case 'O':
			return (bool) preg_match( "/^{$token}:[0-9]+:/s", $data );
		case 'b':
		case 'i':
		case 'd':
			$end = $strict ? '$' : '';
			return (bool) preg_match( "/^{$token}:[0-9.E+-]+;$end/", $data );
	}
	return false;
}

/**
 * Check whether serialized data is of string type.
 *
 * @since 2.0.5
 *
 * @param string $data Serialized data.
 * @return bool False if not a serialized string, true if it is.
 */
function is_serialized_string( $data ) {
	// if it isn't a string, it isn't a serialized string.
	if ( ! is_string( $data ) ) {
		return false;
	}
	$data = trim( $data );
	if ( strlen( $data ) < 4 ) {
		return false;
	} elseif ( ':' !== $data[1] ) {
		return false;
	} elseif ( ';' !== substr( $data, -1 ) ) {
		return false;
	} elseif ( 's' !== $data[0] ) {
		return false;
	} elseif ( '"' !== substr( $data, -2, 1 ) ) {
		return false;
	} else {
		return true;
	}
}

/**
 * Retrieve post title from XMLRPC XML.
 *
 * If the title element is not part of the XML, then the default post title from
 * the $post_default_title will be used instead.
 *
 * @since 0.71
 *
 * @global string $post_default_title Default XML-RPC post title.
 *
 * @param string $content XMLRPC XML Request content
 * @return string Post title
 */
function xmlrpc_getposttitle( $content ) {
	global $post_default_title;
	if ( preg_match( '/<title>(.+?)<\/title>/is', $content, $matchtitle ) ) {
		$post_title = $matchtitle[1];
	} else {
		$post_title = $post_default_title;
	}
	return $post_title;
}

/**
 * Retrieve the post category or categories from XMLRPC XML.
 *
 * If the category element is not found, then the default post category will be
 * used. The return type then would be what $post_default_category. If the
 * category is found, then it will always be an array.
 *
 * @since 0.71
 *
 * @global string $post_default_category Default XML-RPC post category.
 *
 * @param string $content XMLRPC XML Request content
 * @return string|array List of categories or category name.
 */
function xmlrpc_getpostcategory( $content ) {
	global $post_default_category;
	if ( preg_match( '/<category>(.+?)<\/category>/is', $content, $matchcat ) ) {
		$post_category = trim( $matchcat[1], ',' );
		$post_category = explode( ',', $post_category );
	} else {
		$post_category = $post_default_category;
	}
	return $post_category;
}

/**
 * XMLRPC XML content without title and category elements.
 *
 * @since 0.71
 *
 * @param string $content XML-RPC XML Request content.
 * @return string XMLRPC XML Request content without title and category elements.
 */
function xmlrpc_removepostdata( $content ) {
	$content = preg_replace( '/<title>(.+?)<\/title>/si', '', $content );
	$content = preg_replace( '/<category>(.+?)<\/category>/si', '', $content );
	$content = trim( $content );
	return $content;
}

/**
 * Use RegEx to extract URLs from arbitrary content.
 *
 * @since 3.7.0
 *
 * @param string $content Content to extract URLs from.
 * @return string[] Array of URLs found in passed string.
 */
function wp_extract_urls( $content ) {
	preg_match_all(
		"#([\"']?)("
			. '(?:([\w-]+:)?//?)'
			. '[^\s()<>]+'
			. '[.]'
			. '(?:'
				. '\([\w\d]+\)|'
				. '(?:'
					. "[^`!()\[\]{};:'\".,<>«»“”‘’\s]|"
					. '(?:[:]\d+)?/?'
				. ')+'
			. ')'
		. ")\\1#",
		$content,
		$post_links
	);

	$post_links = array_unique( array_map( 'html_entity_decode', $post_links[2] ) );

	return array_values( $post_links );
}

/**
 * Check content for video and audio links to add as enclosures.
 *
 * Will not add enclosures that have already been added and will
 * remove enclosures that are no longer in the post. This is called as
 * pingbacks and trackbacks.
 *
 * @since 1.5.0
 * @since 5.3.0 The `$content` parameter was made optional, and the `$post` parameter was
 *              updated to accept a post ID or a WP_Post object.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string         $content Post content. If `null`, the `post_content` field from `$post` is used.
 * @param int|WP_Post    $post    Post ID or post object.
 * @return null|bool Returns false if post is not found.
 */
function do_enclose( $content = null, $post ) {
	global $wpdb;

	// @todo Tidy this code and make the debug code optional.
	include_once ABSPATH . WPINC . '/class-IXR.php';

	$post = get_post( $post );
	if ( ! $post ) {
		return false;
	}

	if ( null === $content ) {
		$content = $post->post_content;
	}

	$post_links = array();

	$pung = get_enclosed( $post->ID );

	$post_links_temp = wp_extract_urls( $content );

	foreach ( $pung as $link_test ) {
		// Link is no longer in post.
		if ( ! in_array( $link_test, $post_links_temp, true ) ) {
			$mids = $wpdb->get_col( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE post_id = %d AND meta_key = 'enclosure' AND meta_value LIKE %s", $post->ID, $wpdb->esc_like( $link_test ) . '%' ) );
			foreach ( $mids as $mid ) {
				delete_metadata_by_mid( 'post', $mid );
			}
		}
	}

	foreach ( (array) $post_links_temp as $link_test ) {
		// If we haven't pung it already.
		if ( ! in_array( $link_test, $pung, true ) ) {
			$test = parse_url( $link_test );
			if ( false === $test ) {
				continue;
			}
			if ( isset( $test['query'] ) ) {
				$post_links[] = $link_test;
			} elseif ( isset( $test['path'] ) && ( '/' !== $test['path'] ) && ( '' !== $test['path'] ) ) {
				$post_links[] = $link_test;
			}
		}
	}

	/**
	 * Filters the list of enclosure links before querying the database.
	 *
	 * Allows for the addition and/or removal of potential enclosures to save
	 * to postmeta before checking the database for existing enclosures.
	 *
	 * @since 4.4.0
	 *
	 * @param string[] $post_links An array of enclosure links.
	 * @param int      $post_ID    Post ID.
	 */
	$post_links = apply_filters( 'enclosure_links', $post_links, $post->ID );

	foreach ( (array) $post_links as $url ) {
		if ( '' !== $url && ! $wpdb->get_var( $wpdb->prepare( "SELECT post_id FROM $wpdb->postmeta WHERE post_id = %d AND meta_key = 'enclosure' AND meta_value LIKE %s", $post->ID, $wpdb->esc_like( $url ) . '%' ) ) ) {

			$headers = wp_get_http_headers( $url );
			if ( $headers ) {
				$len           = isset( $headers['content-length'] ) ? (int) $headers['content-length'] : 0;
				$type          = isset( $headers['content-type'] ) ? $headers['content-type'] : '';
				$allowed_types = array( 'video', 'audio' );

				// Check to see if we can figure out the mime type from the extension.
				$url_parts = parse_url( $url );
				if ( false !== $url_parts ) {
					$extension = pathinfo( $url_parts['path'], PATHINFO_EXTENSION );
					if ( ! empty( $extension ) ) {
						foreach ( wp_get_mime_types() as $exts => $mime ) {
							if ( preg_match( '!^(' . $exts . ')$!i', $extension ) ) {
								$type = $mime;
								break;
							}
						}
					}
				}

				if ( in_array( substr( $type, 0, strpos( $type, '/' ) ), $allowed_types, true ) ) {
					add_post_meta( $post->ID, 'enclosure', "$url\n$len\n$mime\n" );
				}
			}
		}
	}
}

/**
 * Retrieve HTTP Headers from URL.
 *
 * @since 1.5.1
 *
 * @param string $url        URL to retrieve HTTP headers from.
 * @param bool   $deprecated Not Used.
 * @return bool|string False on failure, headers on success.
 */
function wp_get_http_headers( $url, $deprecated = false ) {
	if ( ! empty( $deprecated ) ) {
		_deprecated_argument( __FUNCTION__, '2.7.0' );
	}

	$response = wp_safe_remote_head( $url );

	if ( is_wp_error( $response ) ) {
		return false;
	}

	return wp_remote_retrieve_headers( $response );
}

/**
 * Determines whether the publish date of the current post in the loop is different
 * from the publish date of the previous post in the loop.
 *
 * For more information on this and similar theme functions, check out
 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
 * Conditional Tags} article in the Theme Developer Handbook.
 *
 * @since 0.71
 *
 * @global string $currentday  The day of the current post in the loop.
 * @global string $previousday The day of the previous post in the loop.
 *
 * @return int 1 when new day, 0 if not a new day.
 */
function is_new_day() {
	global $currentday, $previousday;

	if ( $currentday !== $previousday ) {
		return 1;
	} else {
		return 0;
	}
}

/**
 * Build URL query based on an associative and, or indexed array.
 *
 * This is a convenient function for easily building url queries. It sets the
 * separator to '&' and uses _http_build_query() function.
 *
 * @since 2.3.0
 *
 * @see _http_build_query() Used to build the query
 * @link https://www.php.net/manual/en/function.http-build-query.php for more on what
 *       http_build_query() does.
 *
 * @param array $data URL-encode key/value pairs.
 * @return string URL-encoded string.
 */
function build_query( $data ) {
	return _http_build_query( $data, null, '&', '', false );
}

/**
 * From php.net (modified by Mark Jaquith to behave like the native PHP5 function).
 *
 * @since 3.2.0
 * @access private
 *
 * @see https://www.php.net/manual/en/function.http-build-query.php
 *
 * @param array|object  $data       An array or object of data. Converted to array.
 * @param string        $prefix     Optional. Numeric index. If set, start parameter numbering with it.
 *                                  Default null.
 * @param string        $sep        Optional. Argument separator; defaults to 'arg_separator.output'.
 *                                  Default null.
 * @param string        $key        Optional. Used to prefix key name. Default empty.
 * @param bool          $urlencode  Optional. Whether to use urlencode() in the result. Default true.
 *
 * @return string The query string.
 */
function _http_build_query( $data, $prefix = null, $sep = null, $key = '', $urlencode = true ) {
	$ret = array();

	foreach ( (array) $data as $k => $v ) {
		if ( $urlencode ) {
			$k = urlencode( $k );
		}
		if ( is_int( $k ) && null != $prefix ) {
			$k = $prefix . $k;
		}
		if ( ! empty( $key ) ) {
			$k = $key . '%5B' . $k . '%5D';
		}
		if ( null === $v ) {
			continue;
		} elseif ( false === $v ) {
			$v = '0';
		}

		if ( is_array( $v ) || is_object( $v ) ) {
			array_push( $ret, _http_build_query( $v, '', $sep, $k, $urlencode ) );
		} elseif ( $urlencode ) {
			array_push( $ret, $k . '=' . urlencode( $v ) );
		} else {
			array_push( $ret, $k . '=' . $v );
		}
	}

	if ( null === $sep ) {
		$sep = ini_get( 'arg_separator.output' );
	}

	return implode( $sep, $ret );
}

/**
 * Retrieves a modified URL query string.
 *
 * You can rebuild the URL and append query variables to the URL query by using this function.
 * There are two ways to use this function; either a single key and value, or an associative array.
 *
 * Using a single key and value:
 *
 *     add_query_arg( 'key', 'value', 'http://example.com' );
 *
 * Using an associative array:
 *
 *     add_query_arg( array(
 *         'key1' => 'value1',
 *         'key2' => 'value2',
 *     ), 'http://example.com' );
 *
 * Omitting the URL from either use results in the current URL being used
 * (the value of `$_SERVER['REQUEST_URI']`).
 *
 * Values are expected to be encoded appropriately with urlencode() or rawurlencode().
 *
 * Setting any query variable's value to boolean false removes the key (see remove_query_arg()).
 *
 * Important: The return value of add_query_arg() is not escaped by default. Output should be
 * late-escaped with esc_url() or similar to help prevent vulnerability to cross-site scripting
 * (XSS) attacks.
 *
 * @since 1.5.0
 * @since 5.3.0 Formalized the existing and already documented parameters
 *              by adding `...$args` to the function signature.
 *
 * @param string|array $key   Either a query variable key, or an associative array of query variables.
 * @param string       $value Optional. Either a query variable value, or a URL to act upon.
 * @param string       $url   Optional. A URL to act upon.
 * @return string New URL query string (unescaped).
 */
function add_query_arg( ...$args ) {
	if ( is_array( $args[0] ) ) {
		if ( count( $args ) < 2 || false === $args[1] ) {
			$uri = $_SERVER['REQUEST_URI'];
		} else {
			$uri = $args[1];
		}
	} else {
		if ( count( $args ) < 3 || false === $args[2] ) {
			$uri = $_SERVER['REQUEST_URI'];
		} else {
			$uri = $args[2];
		}
	}

	$frag = strstr( $uri, '#' );
	if ( $frag ) {
		$uri = substr( $uri, 0, -strlen( $frag ) );
	} else {
		$frag = '';
	}

	if ( 0 === stripos( $uri, 'http://' ) ) {
		$protocol = 'http://';
		$uri      = substr( $uri, 7 );
	} elseif ( 0 === stripos( $uri, 'https://' ) ) {
		$protocol = 'https://';
		$uri      = substr( $uri, 8 );
	} else {
		$protocol = '';
	}

	if ( strpos( $uri, '?' ) !== false ) {
		list( $base, $query ) = explode( '?', $uri, 2 );
		$base                .= '?';
	} elseif ( $protocol || strpos( $uri, '=' ) === false ) {
		$base  = $uri . '?';
		$query = '';
	} else {
		$base  = '';
		$query = $uri;
	}

	wp_parse_str( $query, $qs );
	$qs = urlencode_deep( $qs ); // This re-URL-encodes things that were already in the query string.
	if ( is_array( $args[0] ) ) {
		foreach ( $args[0] as $k => $v ) {
			$qs[ $k ] = $v;
		}
	} else {
		$qs[ $args[0] ] = $args[1];
	}

	foreach ( $qs as $k => $v ) {
		if ( false === $v ) {
			unset( $qs[ $k ] );
		}
	}

	$ret = build_query( $qs );
	$ret = trim( $ret, '?' );
	$ret = preg_replace( '#=(&|$)#', '$1', $ret );
	$ret = $protocol . $base . $ret . $frag;
	$ret = rtrim( $ret, '?' );
	return $ret;
}

/**
 * Removes an item or items from a query string.
 *
 * @since 1.5.0
 *
 * @param string|array $key   Query key or keys to remove.
 * @param bool|string  $query Optional. When false uses the current URL. Default false.
 * @return string New URL query string.
 */
function remove_query_arg( $key, $query = false ) {
	if ( is_array( $key ) ) { // Removing multiple keys.
		foreach ( $key as $k ) {
			$query = add_query_arg( $k, false, $query );
		}
		return $query;
	}
	return add_query_arg( $key, false, $query );
}

/**
 * Returns an array of single-use query variable names that can be removed from a URL.
 *
 * @since 4.4.0
 *
 * @return string[] An array of parameters to remove from the URL.
 */
function wp_removable_query_args() {
	$removable_query_args = array(
		'activate',
		'activated',
		'approved',
		'deactivate',
		'deleted',
		'disabled',
		'doing_wp_cron',
		'enabled',
		'error',
		'hotkeys_highlight_first',
		'hotkeys_highlight_last',
		'locked',
		'message',
		'same',
		'saved',
		'settings-updated',
		'skipped',
		'spammed',
		'trashed',
		'unspammed',
		'untrashed',
		'update',
		'updated',
		'wp-post-new-reload',
	);

	/**
	 * Filters the list of query variables to remove.
	 *
	 * @since 4.2.0
	 *
	 * @param string[] $removable_query_args An array of query variables to remove from a URL.
	 */
	return apply_filters( 'removable_query_args', $removable_query_args );
}

/**
 * Walks the array while sanitizing the contents.
 *
 * @since 0.71
 *
 * @param array $array Array to walk while sanitizing contents.
 * @return array Sanitized $array.
 */
function add_magic_quotes( $array ) {
	foreach ( (array) $array as $k => $v ) {
		if ( is_array( $v ) ) {
			$array[ $k ] = add_magic_quotes( $v );
		} else {
			$array[ $k ] = addslashes( $v );
		}
	}
	return $array;
}

/**
 * HTTP request for URI to retrieve content.
 *
 * @since 1.5.1
 *
 * @see wp_safe_remote_get()
 *
 * @param string $uri URI/URL of web page to retrieve.
 * @return string|false HTTP content. False on failure.
 */
function wp_remote_fopen( $uri ) {
	$parsed_url = parse_url( $uri );

	if ( ! $parsed_url || ! is_array( $parsed_url ) ) {
		return false;
	}

	$options            = array();
	$options['timeout'] = 10;

	$response = wp_safe_remote_get( $uri, $options );

	if ( is_wp_error( $response ) ) {
		return false;
	}

	return wp_remote_retrieve_body( $response );
}

/**
 * Set up the WordPress query.
 *
 * @since 2.0.0
 *
 * @global WP       $wp           Current WordPress environment instance.
 * @global WP_Query $wp_query     WordPress Query object.
 * @global WP_Query $wp_the_query Copy of the WordPress Query object.
 *
 * @param string|array $query_vars Default WP_Query arguments.
 */
function wp( $query_vars = '' ) {
	global $wp, $wp_query, $wp_the_query;

	$wp->main( $query_vars );

	if ( ! isset( $wp_the_query ) ) {
		$wp_the_query = $wp_query;
	}
}

/**
 * Retrieve the description for the HTTP status.
 *
 * @since 2.3.0
 * @since 3.9.0 Added status codes 418, 428, 429, 431, and 511.
 * @since 4.5.0 Added status codes 308, 421, and 451.
 * @since 5.1.0 Added status code 103.
 *
 * @global array $wp_header_to_desc
 *
 * @param int $code HTTP status code.
 * @return string Status description if found, an empty string otherwise.
 */
function get_status_header_desc( $code ) {
	global $wp_header_to_desc;

	$code = absint( $code );

	if ( ! isset( $wp_header_to_desc ) ) {
		$wp_header_to_desc = array(
			100 => 'Continue',
			101 => 'Switching Protocols',
			102 => 'Processing',
			103 => 'Early Hints',

			200 => 'OK',
			201 => 'Created',
			202 => 'Accepted',
			203 => 'Non-Authoritative Information',
			204 => 'No Content',
			205 => 'Reset Content',
			206 => 'Partial Content',
			207 => 'Multi-Status',
			226 => 'IM Used',

			300 => 'Multiple Choices',
			301 => 'Moved Permanently',
			302 => 'Found',
			303 => 'See Other',
			304 => 'Not Modified',
			305 => 'Use Proxy',
			306 => 'Reserved',
			307 => 'Temporary Redirect',
			308 => 'Permanent Redirect',

			400 => 'Bad Request',
			401 => 'Unauthorized',
			402 => 'Payment Required',
			403 => 'Forbidden',
			404 => 'Not Found',
			405 => 'Method Not Allowed',
			406 => 'Not Acceptable',
			407 => 'Proxy Authentication Required',
			408 => 'Request Timeout',
			409 => 'Conflict',
			410 => 'Gone',
			411 => 'Length Required',
			412 => 'Precondition Failed',
			413 => 'Request Entity Too Large',
			414 => 'Request-URI Too Long',
			415 => 'Unsupported Media Type',
			416 => 'Requested Range Not Satisfiable',
			417 => 'Expectation Failed',
			418 => 'I\'m a teapot',
			421 => 'Misdirected Request',
			422 => 'Unprocessable Entity',
			423 => 'Locked',
			424 => 'Failed Dependency',
			426 => 'Upgrade Required',
			428 => 'Precondition Required',
			429 => 'Too Many Requests',
			431 => 'Request Header Fields Too Large',
			451 => 'Unavailable For Legal Reasons',

			500 => 'Internal Server Error',
			501 => 'Not Implemented',
			502 => 'Bad Gateway',
			503 => 'Service Unavailable',
			504 => 'Gateway Timeout',
			505 => 'HTTP Version Not Supported',
			506 => 'Variant Also Negotiates',
			507 => 'Insufficient Storage',
			510 => 'Not Extended',
			511 => 'Network Authentication Required',
		);
	}

	if ( isset( $wp_header_to_desc[ $code ] ) ) {
		return $wp_header_to_desc[ $code ];
	} else {
		return '';
	}
}

/**
 * Set HTTP status header.
 *
 * @since 2.0.0
 * @since 4.4.0 Added the `$description` parameter.
 *
 * @see get_status_header_desc()
 *
 * @param int    $code        HTTP status code.
 * @param string $description Optional. A custom description for the HTTP status.
 */
function status_header( $code, $description = '' ) {
	if ( ! $description ) {
		$description = get_status_header_desc( $code );
	}

	if ( empty( $description ) ) {
		return;
	}

	$protocol      = wp_get_server_protocol();
	$status_header = "$protocol $code $description";
	if ( function_exists( 'apply_filters' ) ) {

		/**
		 * Filters an HTTP status header.
		 *
		 * @since 2.2.0
		 *
		 * @param string $status_header HTTP status header.
		 * @param int    $code          HTTP status code.
		 * @param string $description   Description for the status code.
		 * @param string $protocol      Server protocol.
		 */
		$status_header = apply_filters( 'status_header', $status_header, $code, $description, $protocol );
	}

	if ( ! headers_sent() ) {
		header( $status_header, true, $code );
	}
}

/**
 * Get the header information to prevent caching.
 *
 * The several different headers cover the different ways cache prevention
 * is handled by different browsers
 *
 * @since 2.8.0
 *
 * @return array The associative array of header names and field values.
 */
function wp_get_nocache_headers() {
	$headers = array(
		'Expires'       => 'Wed, 11 Jan 1984 05:00:00 GMT',
		'Cache-Control' => 'no-cache, must-revalidate, max-age=0',
	);

	if ( function_exists( 'apply_filters' ) ) {
		/**
		 * Filters the cache-controlling headers.
		 *
		 * @since 2.8.0
		 *
		 * @see wp_get_nocache_headers()
		 *
		 * @param array $headers {
		 *     Header names and field values.
		 *
		 *     @type string $Expires       Expires header.
		 *     @type string $Cache-Control Cache-Control header.
		 * }
		 */
		$headers = (array) apply_filters( 'nocache_headers', $headers );
	}
	$headers['Last-Modified'] = false;
	return $headers;
}

/**
 * Set the headers to prevent caching for the different browsers.
 *
 * Different browsers support different nocache headers, so several
 * headers must be sent so that all of them get the point that no
 * caching should occur.
 *
 * @since 2.0.0
 *
 * @see wp_get_nocache_headers()
 */
function nocache_headers() {
	if ( headers_sent() ) {
		return;
	}

	$headers = wp_get_nocache_headers();

	unset( $headers['Last-Modified'] );

	header_remove( 'Last-Modified' );

	foreach ( $headers as $name => $field_value ) {
		header( "{$name}: {$field_value}" );
	}
}

/**
 * Set the headers for caching for 10 days with JavaScript content type.
 *
 * @since 2.1.0
 */
function cache_javascript_headers() {
	$expiresOffset = 10 * DAY_IN_SECONDS;

	header( 'Content-Type: text/javascript; charset=' . get_bloginfo( 'charset' ) );
	header( 'Vary: Accept-Encoding' ); // Handle proxies.
	header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', time() + $expiresOffset ) . ' GMT' );
}

/**
 * Retrieve the number of database queries during the WordPress execution.
 *
 * @since 2.0.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @return int Number of database queries.
 */
function get_num_queries() {
	global $wpdb;
	return $wpdb->num_queries;
}

/**
 * Whether input is yes or no.
 *
 * Must be 'y' to be true.
 *
 * @since 1.0.0
 *
 * @param string $yn Character string containing either 'y' (yes) or 'n' (no).
 * @return bool True if yes, false on anything else.
 */
function bool_from_yn( $yn ) {
	return ( strtolower( $yn ) == 'y' );
}

/**
 * Load the feed template from the use of an action hook.
 *
 * If the feed action does not have a hook, then the function will die with a
 * message telling the visitor that the feed is not valid.
 *
 * It is better to only have one hook for each feed.
 *
 * @since 2.1.0
 *
 * @global WP_Query $wp_query WordPress Query object.
 */
function do_feed() {
	global $wp_query;

	$feed = get_query_var( 'feed' );

	// Remove the pad, if present.
	$feed = preg_replace( '/^_+/', '', $feed );

	if ( '' == $feed || 'feed' === $feed ) {
		$feed = get_default_feed();
	}

	if ( ! has_action( "do_feed_{$feed}" ) ) {
		wp_die( __( 'Error: This is not a valid feed template.' ), '', array( 'response' => 404 ) );
	}

	/**
	 * Fires once the given feed is loaded.
	 *
	 * The dynamic portion of the hook name, `$feed`, refers to the feed template name.
	 * Possible values include: 'rdf', 'rss', 'rss2', and 'atom'.
	 *
	 * @since 2.1.0
	 * @since 4.4.0 The `$feed` parameter was added.
	 *
	 * @param bool   $is_comment_feed Whether the feed is a comment feed.
	 * @param string $feed            The feed name.
	 */
	do_action( "do_feed_{$feed}", $wp_query->is_comment_feed, $feed );
}

/**
 * Load the RDF RSS 0.91 Feed template.
 *
 * @since 2.1.0
 *
 * @see load_template()
 */
function do_feed_rdf() {
	load_template( ABSPATH . WPINC . '/feed-rdf.php' );
}

/**
 * Load the RSS 1.0 Feed Template.
 *
 * @since 2.1.0
 *
 * @see load_template()
 */
function do_feed_rss() {
	load_template( ABSPATH . WPINC . '/feed-rss.php' );
}

/**
 * Load either the RSS2 comment feed or the RSS2 posts feed.
 *
 * @since 2.1.0
 *
 * @see load_template()
 *
 * @param bool $for_comments True for the comment feed, false for normal feed.
 */
function do_feed_rss2( $for_comments ) {
	if ( $for_comments ) {
		load_template( ABSPATH . WPINC . '/feed-rss2-comments.php' );
	} else {
		load_template( ABSPATH . WPINC . '/feed-rss2.php' );
	}
}

/**
 * Load either Atom comment feed or Atom posts feed.
 *
 * @since 2.1.0
 *
 * @see load_template()
 *
 * @param bool $for_comments True for the comment feed, false for normal feed.
 */
function do_feed_atom( $for_comments ) {
	if ( $for_comments ) {
		load_template( ABSPATH . WPINC . '/feed-atom-comments.php' );
	} else {
		load_template( ABSPATH . WPINC . '/feed-atom.php' );
	}
}

/**
 * Displays the default robots.txt file content.
 *
 * @since 2.1.0
 * @since 5.3.0 Remove the "Disallow: /" output if search engine visiblity is
 *              discouraged in favor of robots meta HTML tag in wp_no_robots().
 */
function do_robots() {
	header( 'Content-Type: text/plain; charset=utf-8' );

	/**
	 * Fires when displaying the robots.txt file.
	 *
	 * @since 2.1.0
	 */
	do_action( 'do_robotstxt' );

	$output = "User-agent: *\n";
	$public = get_option( 'blog_public' );

	$site_url = parse_url( site_url() );
	$path     = ( ! empty( $site_url['path'] ) ) ? $site_url['path'] : '';
	$output  .= "Disallow: $path/wp-admin/\n";
	$output  .= "Allow: $path/wp-admin/admin-ajax.php\n";

	/**
	 * Filters the robots.txt output.
	 *
	 * @since 3.0.0
	 *
	 * @param string $output The robots.txt output.
	 * @param bool   $public Whether the site is considered "public".
	 */
	echo apply_filters( 'robots_txt', $output, $public );
}

/**
 * Display the favicon.ico file content.
 *
 * @since 5.4.0
 */
function do_favicon() {
	/**
	 * Fires when serving the favicon.ico file.
	 *
	 * @since 5.4.0
	 */
	do_action( 'do_faviconico' );

	wp_redirect( get_site_icon_url( 32, admin_url( 'images/w-logo-blue.png' ) ) );
	exit;
}

/**
 * Determines whether WordPress is already installed.
 *
 * The cache will be checked first. If you have a cache plugin, which saves
 * the cache values, then this will work. If you use the default WordPress
 * cache, and the database goes away, then you might have problems.
 *
 * Checks for the 'siteurl' option for whether WordPress is installed.
 *
 * For more information on this and similar theme functions, check out
 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
 * Conditional Tags} article in the Theme Developer Handbook.
 *
 * @since 2.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @return bool Whether the site is already installed.
 */
function is_blog_installed() {
	global $wpdb;

	/*
	 * Check cache first. If options table goes away and we have true
	 * cached, oh well.
	 */
	if ( wp_cache_get( 'is_blog_installed' ) ) {
		return true;
	}

	$suppress = $wpdb->suppress_errors();
	if ( ! wp_installing() ) {
		$alloptions = wp_load_alloptions();
	}
	// If siteurl is not set to autoload, check it specifically.
	if ( ! isset( $alloptions['siteurl'] ) ) {
		$installed = $wpdb->get_var( "SELECT option_value FROM $wpdb->options WHERE option_name = 'siteurl'" );
	} else {
		$installed = $alloptions['siteurl'];
	}
	$wpdb->suppress_errors( $suppress );

	$installed = ! empty( $installed );
	wp_cache_set( 'is_blog_installed', $installed );

	if ( $installed ) {
		return true;
	}

	// If visiting repair.php, return true and let it take over.
	if ( defined( 'WP_REPAIRING' ) ) {
		return true;
	}

	$suppress = $wpdb->suppress_errors();

	/*
	 * Loop over the WP tables. If none exist, then scratch installation is allowed.
	 * If one or more exist, suggest table repair since we got here because the
	 * options table could not be accessed.
	 */
	$wp_tables = $wpdb->tables();
	foreach ( $wp_tables as $table ) {
		// The existence of custom user tables shouldn't suggest an insane state or prevent a clean installation.
		if ( defined( 'CUSTOM_USER_TABLE' ) && CUSTOM_USER_TABLE == $table ) {
			continue;
		}
		if ( defined( 'CUSTOM_USER_META_TABLE' ) && CUSTOM_USER_META_TABLE == $table ) {
			continue;
		}

		if ( ! $wpdb->get_results( "DESCRIBE $table;" ) ) {
			continue;
		}

		// One or more tables exist. We are insane.

		wp_load_translations_early();

		// Die with a DB error.
		$wpdb->error = sprintf(
			/* translators: %s: Database repair URL. */
			__( 'One or more database tables are unavailable. The database may need to be <a href="%s">repaired</a>.' ),
			'maint/repair.php?referrer=is_blog_installed'
		);

		dead_db();
	}

	$wpdb->suppress_errors( $suppress );

	wp_cache_set( 'is_blog_installed', false );

	return false;
}

/**
 * Retrieve URL with nonce added to URL query.
 *
 * @since 2.0.4
 *
 * @param string     $actionurl URL to add nonce action.
 * @param int|string $action    Optional. Nonce action name. Default -1.
 * @param string     $name      Optional. Nonce name. Default '_wpnonce'.
 * @return string Escaped URL with nonce action added.
 */
function wp_nonce_url( $actionurl, $action = -1, $name = '_wpnonce' ) {
	$a…