Re: Don't you think there are too many *sum utilities?

[Elias Pipping]

On Apr 9, 2007, at 2:28 PM, Eric Blake wrote:

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> According to Alfred M. Szmidt on 4/9/2007 6:17 AM:
> > > I don't see any major problem why something like `hashsum
> > > ALGORITHM' wouldn't work though, `md5sum' could be the same as
> > > `hashsum md5'.  And then md5sum could be a shell script, or just
> > > a simple program that calls `hashsum md5'.
> >
> >    Except that since the *sum utilities operate on arbitrary files,
> >    you would need it to be `hashsum --md5', ie. make the algorithm an
> >    option rather than the first argument.
> >
> > Why not just: hashsum ALGORITHM [FILE]? A optional hashing algorithm
> > seems pointless for this.
>
> Because on decoding, 'hashsum -c FILE' could be made smart enough to
> auto-detect the algorithm based on the length of the hash, but only  
> if the
> algorithm is optional (--md5) rather than required (md5).   
> Currently, md5,
> sha1, sha224, sha256, sha384, and sha512 all produce different hash
> lengths, making this task unambiguous (but I'm not sure how long  
> md4 is).

md2, md4 and md5 share the same length (32), as well as sha, sha1 and  
rmd160 (40)

  $openssl dgst -md5 coreutils-6.9.tar.bz2
  MD5(coreutils-6.9.tar.bz2)= c9607d8495f16e98906e7ed2d9751a06
  $openssl dgst -md4 coreutils-6.9.tar.bz2
  MD4(coreutils-6.9.tar.bz2)= eeb5317a341a5d1e4fa7a751dce2f979
  $openssl dgst -md2 coreutils-6.9.tar.bz2
  MD2(coreutils-6.9.tar.bz2)= f3a7bedf4cc502c76cc84eaee93283b1

  $openssl dgst -rmd160 coreutils-6.9.tar.bz2
  RIPEMD160(coreutils-6.9.tar.bz2)=  
c6ae65204b2e9c234a1140f39a8be1ee5cdcaab7
  $openssl dgst -sha1 coreutils-6.9.tar.bz2
  SHA1(coreutils-6.9.tar.bz2)= 10310a78c4e1d9f742f3815ac28e9bf1086a5885
  $openssl dgst -sha coreutils-6.9.tar.bz2
  SHA(coreutils-6.9.tar.bz2)= 6ffdef6b4a1f055326d7b5427de1145b5e9a8da1


Regards,

Elias Pipping