Data commit

Task/CRC-32/PowerBASIC/crc-32.basic

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+#COMPILE EXE
+#DIM ALL
+#COMPILER PBCC 6
+
+' ***********
+
+FUNCTION CRC32(BYVAL p AS BYTE PTR, BYVAL NumBytes AS DWORD) AS DWORD
+  STATIC LUT() AS DWORD
+  LOCAL i, j, k, crc AS DWORD
+
+  IF ARRAYATTR(LUT(), 0) = 0 THEN
+    REDIM LUT(0 TO 255)
+    FOR i = 0 TO 255
+      k = i
+      FOR j = 0 TO 7
+        IF (k AND 1) THEN
+          SHIFT RIGHT k, 1
+          k XOR= &HEDB88320
+        ELSE
+          SHIFT RIGHT k, 1
+        END IF
+      NEXT j
+      LUT(i) = k
+    NEXT i
+  END IF
+
+  crc = &HFFFFFFFF
+
+  FOR i = 0 TO NumBytes - 1
+    k = (crc AND &HFF& XOR @p[i])
+    SHIFT RIGHT crc, 8
+    crc XOR= LUT(k)
+  NEXT i
+
+  FUNCTION = NOT crc
+END FUNCTION
+
+' ***********
+
+FUNCTION PBMAIN () AS LONG
+  LOCAL s AS STRING
+  LOCAL crc AS DWORD
+
+  s = "The quick brown fox jumps over the lazy dog"
+  CON.PRINT "Text:  " & s
+  crc = CRC32(STRPTR(s), LEN(s))
+  CON.PRINT "CRC32: " & HEX$(crc)
+END FUNCTION