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<?php |
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|
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if ( ! defined( 'ABSPATH' ) ) { |
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die( 'You are not allowed to call this page directly.' ); |
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} |
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|
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/** |
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* Given a string, this class will read through the string using |
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* one of a number of terminating rules: |
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* - One character. |
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* - A specified number of characters. |
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* - Until a matching character is found. |
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* |
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* @since 6.2 |
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*/ |
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class FrmStringReaderHelper { |
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|
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/** |
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* @var int |
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*/ |
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private $pos = 0; |
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|
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/** |
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* @var int |
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*/ |
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private $max = 0; |
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|
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/** |
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* @var string |
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*/ |
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private $string; |
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|
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/** |
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* @param string $string |
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*/ |
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public function __construct( $string ) { |
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// Split the string up into an array of UTF-8 characters. |
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// As an array we can read through it one character at a time. |
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|
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$this->string = $string; |
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$this->max = strlen( $this->string ) - 1; |
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} |
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|
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/** |
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* Read characters until we reach the given character $char. |
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* By default, discard that final matching character and return the rest. |
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* |
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* @param string $char |
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* @param bool $discard_char |
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* @return string |
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*/ |
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public function read_until( $char, $discard_char = true ) { |
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$value = ''; |
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|
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while ( null !== ( $one = $this->read_one() ) ) { |
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if ( $one !== $char || ! $discard_char ) { |
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$value .= $one; |
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} |
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|
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if ( $one === $char ) { |
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break; |
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} |
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} |
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|
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return $value; |
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} |
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|
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/** |
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* Read $count characters, or until we have reached the end, |
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* whichever comes first. |
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* By default, remove enclosing double-quotes from the result. |
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* |
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* @param int $count |
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* @return string |
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*/ |
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public function read( $count ) { |
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$value = ''; |
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|
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while ( $count > 0 && ! is_null( $one = $this->read_one() ) ) { |
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$value .= $one; |
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--$count; |
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} |
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|
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return $this->strip_quotes( $value ); |
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} |
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|
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/** |
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* Read the next character from the supplied string. |
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* Return null when we have run out of characters. |
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* |
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* @return string|null |
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*/ |
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private function read_one() { |
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if ( $this->pos <= $this->max ) { |
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$value = $this->string[ $this->pos ]; |
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$this->pos += 1; |
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} else { |
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$value = null; |
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} |
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return $value; |
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} |
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|
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/** |
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* Remove a single set of double-quotes from around a string. |
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* abc => abc |
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* "abc" => abc |
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* ""abc"" => "abc" |
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* |
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* @param string string |
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* @return string |
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*/ |
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private function strip_quotes( $string ) { |
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// Only remove exactly one quote from the start and the end and then only if there is one at each end. |
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|
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if ( strlen( $string ) < 2 || substr( $string, 0, 1 ) !== '"' || substr( $string, -1, 1 ) !== '"' ) { |
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// Too short, or does not start or end with a quote. |
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return $string; |
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} |
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|
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// Return the middle of the string, from the second character to the second-but-last. |
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return substr( $string, 1, -1 ); |
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} |
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} |
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|
