RosettaCodeData/Task/CRC-32/QB64/crc-32.qb64
2023-07-01 13:44:08 -04:00

32 lines
812 B
Text

PRINT HEX$(crc32("The quick brown fox jumps over the lazy dog"))
FUNCTION crc32~& (buf AS STRING)
STATIC table(255) AS _UNSIGNED LONG
STATIC have_table AS _BYTE
DIM crc AS _UNSIGNED LONG, k AS _UNSIGNED LONG
DIM i AS LONG, j AS LONG
IF have_table = 0 THEN
FOR i = 0 TO 255
k = i
FOR j = 0 TO 7
IF (k AND 1) THEN
k = _SHR(k, 1)
k = k XOR &HEDB88320
ELSE
k = _SHR(k, 1)
END IF
table(i) = k
NEXT
NEXT
have_table = -1
END IF
crc = NOT crc ' crc = &Hffffffff
FOR i = 1 TO LEN(buf)
crc = (_SHR(crc, 8)) XOR table((crc AND &HFF) XOR ASC(buf, i))
NEXT
crc32~& = NOT crc
END FUNCTION