MD5 digests of very big files

Jan Schenkel janschenkel at
Mon Jun 28 00:34:17 EDT 2010

--- On Sun, 6/27/10, Alejandro Tejada <capellan2000 at> wrote:
> Hi Jacke,
> Jacqueline Landman Gay wrote:
> > Try: if it is empty 
> Many Thanks!
> This works. :-D
> Now the function will be:
> function quasiMD5 pFile
>   local tMD5s
>   open file pFile for binary read
>   repeat
>     read from file pFile for 4096 chars
>     if it is empty then
>       exit repeat
>     end if
>     put the md5digest of it after tMD5s
>   end repeat
>   close file pFile
>   return the md5Digest of tMD5s
> end quasiMD5

To make this future-proof, you might want to use the byte chunk type for reading from the binary file:
   read from file pFile for 4096 bytes  -- was: chars
That way, after Unicode support in the revEngine becomes pervasive and transparent, the above will work just fine, whether or not the intricacies of what constitutes a 'char' change.

Jan Schenkel
Quartam Reports & PDF Library for Revolution

"As we grow older, we grow both wiser and more foolish at the same time."  (La Rochefoucauld)


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