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<?php function string_shift_left($input, $inputlen, $bits, &$output = null) { $skip = (int) ($bits / 8); $copylen = (int) ($inputlen - $skip); $offset = $bits % 8; $mask = 0xff >> $offset; $output = str_pad('', $inputlen + 1, "\x00"); var_dump($skip, $copylen, $offset, $mask, $output); if ($offset == 0) { /* Shifting multiples of 8 allows us to simply copy the relevant bytes */ for ($i = 0; $i < $copylen; $i++) { $output[$i] = $input[$i + $skip]; } return; } for ($i = 0; $i < $copylen; $i++) { $output[$i] = chr((ord($input[$i + $skip]) << $offset) | (ord($input[$i + $skip + 1]) & $mask)); } } string_shift_left("\x01\x01\x00", 2, 7, $output); for ($i = 0; $i < strlen($output); $i++) { printf('%08b|', ord($output[$i])); }

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