P
Paul Golea
Hello,
I try to calculate the CRC32 of a file with a script ruby, but I does
not obtain the good result by comparison with many of the other software
which already make this (in other programming language...), for example:
http://www.codeproject.com/KB/recipes/crc32.aspx
I use this script :
_____________________
require 'zlib'
filetest = File.read 'image.jpg'
puts Zlib.crc32(filetest, 0).to_s(16).upcase
_____________________
The result looks like well of an CRC32 but it is never good...
I also try a pure ruby implementation with this code but it makes
exactly the zlib.crc32 result... :
_____________________
def crc32(c)
n = c.length
r = 0xFFFFFFFF
n.times do |i|
r ^= c
8.times do
if (r & 1)!=0
r = (r>>1) ^ 0xEDB88320
else
r >>= 1
end
end
end
r ^ 0xFFFFFFFF
end
filetest = File.read 'image.jpg'
puts crc32(filetest).to_s(16).upcase
_____________________
Thank you very much to the person who will have the solution of my
problem.
I try to calculate the CRC32 of a file with a script ruby, but I does
not obtain the good result by comparison with many of the other software
which already make this (in other programming language...), for example:
http://www.codeproject.com/KB/recipes/crc32.aspx
I use this script :
_____________________
require 'zlib'
filetest = File.read 'image.jpg'
puts Zlib.crc32(filetest, 0).to_s(16).upcase
_____________________
The result looks like well of an CRC32 but it is never good...
I also try a pure ruby implementation with this code but it makes
exactly the zlib.crc32 result... :
_____________________
def crc32(c)
n = c.length
r = 0xFFFFFFFF
n.times do |i|
r ^= c
8.times do
if (r & 1)!=0
r = (r>>1) ^ 0xEDB88320
else
r >>= 1
end
end
end
r ^ 0xFFFFFFFF
end
filetest = File.read 'image.jpg'
puts crc32(filetest).to_s(16).upcase
_____________________
Thank you very much to the person who will have the solution of my
problem.