Messages in this thread |  | | Date | Sat, 26 Aug 2000 03:13:27 -0400 | From | Michael Rothwell <> | Subject | Re: Driver for the :Cue:Cat barcode reader |
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There is a better way to decode CueCat output. Colin Cross sent me this info:
Taral (taral@taral.net) wrote the original version in python (http://ccwf.cc.utexas.edu/~taral/cat.py), and I've converted it to perl (http://www.mit.edu/~colin/cat.pl) and C (http://www.mit.edu/~colin/cat.c).
It's a rather simple formula: each character is a base-64 (6-bit) number ('a' to 'z' is 0 to 25, 'A' to 'Z' is 26 to 51, '0' to '9' is 52 to 61, '+' is 62, '-'is 63). The 4 6-bit numbers are combined into a single 24-bit number, which is split into 3 8-bit numbers. Each 8-bit number is XOR'd with 67 (decimal) to produce the final ASCII code.
Not quite sure how Taral figured it out, but it works well, decodes alphanumeric codes (such as the UPS tracking numbers), and produces useful data out of the type codes (128 for a Code-128, UPA for a UPC-A, etc.) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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