[EMAIL PROTECTED] (Michael O'Donnell) writes:
> Thank you. I think. For the benefit of those > here assembled, please supply an explanation. OK, since you asked. You have a list of stuff that you want sorted. The problem is is that you want your stuff sorted according to a field contained in the input (the last field). Further complicating matters is the fact that this field is located at a non-constant place in the input field. (I initially thought about using "sort", but then I had trouble with the sort options, and I gave up and used my favorite tool: Perl) Now, just to complicate matters, suppose your input consisted of a million filenames (or so). How to do this efficiently? Big suggestion: finding all of those comparison fields, once per sort comparison, is going to be really expensive... The solution: take the input, generate a list from each line, each element in the list consists of a tuple consisting of the original line plus the comparison key. Sort the tuple-list using the comparison key, and then after the sort is done, strip off all of the comparison keys, returning the original list ({sans} tuples), sorted. This is actually a well-known technique in Perl, called the Schwartzian Transform. Look it up on the web -- there are plenty of good descriptions of it. > BTW, this is actually a fairly good example of > why my immune system always concludes that I'm > in physical danger when perl code is visible... Honestly, I wrote that one-liner more with the intent of showing you how cool Perl is, not with the intent of scaring you off from Perl. Regards, --kevin -- Kevin D. Clark / Cetacean Networks / Portsmouth, N.H. (USA) cetaceannetworks.com!kclark (GnuPG ID: B280F24E) alumni.unh.edu!kdc _______________________________________________ gnhlug-discuss mailing list [EMAIL PROTECTED] http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss