|REBOL 3 Docs||Guide||Concepts||Functions||Datatypes||Errors|
|TOC < Back Next >||Updated: 3-Aug-2010 Edit History|
Computes a checksum, CRC, or hash.
data [binary!] - Byte string to checksum
/tcp - Returns an Internet TCP 16-bit checksum
/secure - Returns a cryptographically secure checksum
/hash - Returns a hash value
size [integer!] - Size of the hash table
/method - Method to use
word [word!] - Method: SHA1 MD5
/key - Returns keyed HMAC value
key-value [any-string!] - Key to use
Generally, a checksum is a number which accompanies data to verify that the data has not changed (did not have errors).
Editor note: R3 does not yet allow string! for checksums.
print checksum "now is the dawning" print checksum "how is the dawning"
The /secure refinement creates a binary string result that is cryptographically secure:
print checksum/secure "fred-key" print checksum/secure form now
The /tcp refinement is used to compute the standard TCP networking checksum. This is a weak but fast checksum method.
print checksum/tcp "now is the dawning" print checksum/tcp "how is the dawning"
|TOC < Back Next >||REBOL.com - WIP Wiki||Feedback Admin|