From: Wu Junchen <wujunchen@...>
Date: 2007-12-13T22:26:49+09:00
Subject: Re: read write integer in binary into a file

Vianney Lecroart wrote:
> Hello,
> 
> I have some big files with lot of "unsigned int" (4 bytes) numbers and I
> want to read and write on these files.
> 
> Currently, I found this to write:
> 
> myfile << [mynum].pack("i")
> 
> and to read:
> 
> mynum = myfile.read(4).unpack("i").first
> 
> I wonder if there's not something faster/simpler to do that without the
> need to convert the number into an array into a string to finally
> serialize it.
> 
> Thank you.


irb(main):001:0> f=open('test','w')
=> #<File:test>
irb(main):002:0> f<<[65535].pack('i')
=> #<File:test>
irb(main):003:0> f.tell
=> 4
irb(main):004:0> f<<[720850].pack('i')
=> #<File:test>
irb(main):005:0> f.tell
=> 9
the integer 720850 takes 5 bytes in my file,but it should take 4 bytes 
only!How can I fix this?Thanks!
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