LostS has asked for the wisdom of the Perl Monks concerning the following question:

OK Sorting is a pain in my ....
So here we go...

I have 4 flat files. Tab delimited data the 3rd and 4th tab is LastName then FirstName.
OK here is what I currently have that will sort by field 3... 
my @sorted_list = 
     map { $database_in[ $$_[0] ] }
     sort { $$a[1] cmp $$b[1] }
     map { [ $_, (split /\t/, $database_in[ $_ ])[3] ] }(0..@database_
+in-1);

[download]
Now... I need to also sort the array first by field 3 like it does but also by field 4...
I need Jayne Williams to come before Jeff Williams... Any suggestions??


-----------------------
Billy S.
Slinar Hardtail - Guildless
Datal Ephialtes - Guildless
RallosZek.Net Admin/WebMaster
Aerynth.Net Admin/WebMaster

perl -e '$cat = "cat"; if ($cat =~ /\143\x61\x74/) { print "Its a cat!
+\n"; } else { print "Thats a dog\n"; } print "\n";'

[download]

Replies are listed 'Best First'.
Re: Sort Question (Again) :(
by davorg (Chancellor) on Oct 19, 2001 at 20:20 UTC 
    my @sorted_list = 
     map { $_->[0] }
     sort { $a->[1] cmp $b->[1] or $a->[2] cmp $b->[2] }
     map { [ $_, (split /\t/)[3,4] ] } @database_in;

    [download]

    I made a few stylistic changes too :)

    Update: Removed $_ from split. Hofmator is right - it was an artifact from the refactoring :(

    --
    <http://www.dave.org.uk>

    "The first rule of Perl club is you don't talk about Perl club."

[reply]
[d/l]

      ++davorg, I just wanted to suggest the same thing, including the same stylistic changes :). But where do you see the benefit of giving split the explicit $_, instead of simply (split /\t/)[3,4]?

      -- Hofmator

[reply]
[d/l]
      HEY.. I found out why Jeff was coming before Jayne... And my god that can be a loaded answer or question... Anyways...
      The problem is Jeff has a space in front of his name... Now how would I say ignore the space in the front of all fields and then sort??


      -----------------------
      Billy S.
      Slinar Hardtail - Guildless
      Datal Ephialtes - Guildless
      RallosZek.Net Admin/WebMaster
      Aerynth.Net Admin/WebMaster

      perl -e '$cat = "cat"; if ($cat =~ /\143\x61\x74/) { print "Its a cat!
+\n"; } else { print "Thats a dog\n"; } print "\n";'

      [download]
[reply]
[d/l]

        Change the split criteria to remove whitespace as well. Building on davorg's code:

        my @sorted_list = 
     map { $_->[0] }
     sort { $a->[1] cmp $b->[1] or $a->[2] cmp $b->[2] }
     map { [ $_, (split /\t\s*/)[3,4] ] } @database_in;

        [download]

        Blessed Be
        The Pixel

[reply]
[d/l]
        See answer below.
[reply]
      Just tried exactly what you put... and this is the order it gave me...

      Jeff Williams
      Jayne Williams
      Phil Williams

      Doesn't Jayne come before Jeff??

      -----------------------
      Billy S.
      Slinar Hardtail - Guildless
      Datal Ephialtes - Guildless
      RallosZek.Net Admin/WebMaster
      Aerynth.Net Admin/WebMaster

      perl -e '$cat = "cat"; if ($cat =~ /\143\x61\x74/) { print "Its a cat!
+\n"; } else { print "Thats a dog\n"; } print "\n";'

      [download]
[reply]
[d/l]
        Yeah, but 'Wiliams' comes before 'Williams' ... :-)

        ------
        We are the carpenters and bricklayers of the Information Age.

        Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

[reply]
Re: Sort Question (Again) :(
by runrig (Abbot) on Oct 19, 2001 at 20:39 UTC 
    my @sorted_list = 
     map { $$_[0] }
     sort { $$a[1] cmp $$b[1] }
     map { [ $_, do{
      my $tmp = join "\x00", (split /\t/)[3,4];
      $tmp =~ s/(^|\x00)\s+/$1/g;$tmp } ]
     } @database_in;

    [download]
    Update:With extra added condition of stripping leading spaces. Fixed. Can't have 'local $_' inside do{} block due to split using outer $_.
[reply]
[d/l]
      You all rock :)
      Here is the code that sorts properly and gets rid of the stinking space..

      my @sorted_list = 
    map { $$_[0] }
    sort { $$a[1] cmp $$b[1] }
    map { [ $_, do{
        my $tmp = join "\x00", (split /\t/)[3,4];
        $tmp =~ s/(^|\x00)\s+/$1/g;$tmp } ]
    } @database_in;

      [download]
      Thank you all for this help :)

      Update: Change code cause it didn't work 100%... This code does though.. OK I am just using the code above now :) Thank you again :)


      -----------------------
      Billy S.
      Slinar Hardtail - Guildless
      Datal Ephialtes - Guildless
      RallosZek.Net Admin/WebMaster
      Aerynth.Net Admin/WebMaster

      perl -e '$cat = "cat"; if ($cat =~ /\143\x61\x74/) { print "Its a cat!
+\n"; } else { print "Thats a dog\n"; } print "\n";'

      [download]
[reply]
[d/l]
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