Re: Hash function of strings
- To: mathgroup at smc.vnet.net
- Subject: [mg95066] Re: Hash function of strings
- From: Joseph Gwinn <joegwinn at comcast.net>
- Date: Mon, 5 Jan 2009 03:27:38 -0500 (EST)
- References: <gjng6s$2ls$1@smc.vnet.net> <gjqa2r$3aa$1@smc.vnet.net>
In article <gjqa2r$3aa$1 at smc.vnet.net>, "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com> wrote: > I don't think it's possible. Hash works on Mathematica expressions and > there is no way that a string expression can be converted to an > expression consisting of its binary equivalent only. If there would be > a structure "binary sequence" or so, it must have a Head in > Mathematica designating it as such and then we're back at something > like the string problem. > > Cheers --Sjoerd > > On Jan 3, 12:55 pm, Nacho <ncc1701... at gmail.com> wrote: > > Hello all. > > > > I'm trying to calculate the MD5 Hash function of a series of strings > > and I'm getting different results from the "true" MD5. > > > > I have searched the group and I have found that the Hash[] function is > > including the " " of the strings. A solution is proposed, creating a > > temporary file and then using FileHash. > > > > My problem is that I want to calculate the Hash of about one million > > strings, so creating temporary files is impossible. > > > > Can you think in a method to calculate the Hash very quickly, without > > the " "? > > > > Thanks a lot. A million hashes? Performance will also be an issue. Use MathLink to access one of the standard C-coded MD5 functions via some C glue code that will strip the quotes, et al. Joe Gwinn