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<?php function str_compare(string $left, string $right): int { $length = mb_strlen($left, '8bit'); if (mb_strlen($right, '8bit') !== $length) { throw new Exception('ct_select() expects two strings of equal length'); } $gt = 0; $eq = 1; $i = $length; while ($i > 0) { --$i; $leftCharCode = unpack('C', $left[$i])[1]; $rightCharCode = unpack('C', $right[$i])[1]; $gt |= (($rightCharCode - $leftCharCode) >> 8) & $eq; $eq &= (($rightCharCode ^ $leftCharCode) -1) >> 8; } return ($gt + $gt + $eq) - 1; } var_dump( str_compare('baaaaaaaa', 'aaaaaaaaa'), str_compare('aaaaaaaaa', 'aaaaaaaaa'), str_compare('aaaaaaaaa', 'baaaaaaaa') );
Output for 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.30, 8.2.0 - 8.2.25, 8.3.0 - 8.3.14
int(1) int(0) int(-1)

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47.88 ms | 407 KiB | 5 Q