in reply to Re^2: checksum of subroutine
in thread checksum of subroutine

Use Digest::SHA to calculate a digest over the whole file. Although it is not impossible to make two totally different files with the same digest, it is extremely unlikely that both files will have the same length and both will be working programs. It is not as simple as changing a few instructions and adding a few meaningless bytes at the end to "make up" the checksum.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

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