Gossamer Forum: General: Perl Programming: Sort problem

Apr 25, 2003, 11:09 AM

sws_mark

New User (4 posts)

Apr 25, 2003, 11:09 AM

Post #1 of 10

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Sort problem

I am a Perl newbie who (until I started to try to sort my flatfile database) was able to modify what I found in books and in tutorials.

I have pieced together a Perl program that will allow me to add, edit, and delete records in a pipe-delimited database. However, I cannot formulate a correct sort routine.

Here is the relevant portion of my code:

Code:


open (DATABASE,">$database"); 
@DB=<DATABASE>; 
 foreach $rec (@DATAB){ 
  chomp($rec); 
  ($name,$company,$score)=split(/\|/,$rec); 
  if ($name eq $input{'name'} && $company eq $input{'company'} && $score eq $input{'score'}){ 
  print DATABASE "$input{'nname'}|$input{'ncompany'}|$input{'nscore'}\n"; 
  }else{ 
  print DATABASE "$name|$company|$score\n"; 
  } 
 } 
close (DATABASE);  

@DATABASE = sort { 
 $score{$b} <=> $score{$a} or $company{$a} cmp $company{$b} or $name{$a} cmp $name{$b} 
} @DATAB;  

foreach $rec (@DATABASE){ 
 chomp($rec); 
 ($name,$company,$score)=split(/\|/,$rec); 
 print DATABASE "$name|$company|$score\n"; 
 }

Can anyone please tell me what I am screwing up? (This code will run without error, but it does not sort.)

Apr 25, 2003, 11:52 AM

Paul

Veteran (19537 posts)

Apr 25, 2003, 11:52 AM

Post #2 of 10

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Re: [sws_mark] Sort problem In reply to

You are storing the file in @DB but then looping @DATAB?...where did @DATAB come from?

Apr 25, 2003, 12:21 PM

fuzzy logic

Enthusiast (854 posts)

Apr 25, 2003, 12:21 PM

Post #3 of 10

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Re: [Paul] Sort problem In reply to

you are also sorting a hash that isn't defined anywhere in the code you provided.

Philip
------------------
Limecat is not pleased.

Apr 25, 2003, 12:38 PM

sws_mark

New User (4 posts)

Apr 25, 2003, 12:38 PM

Post #4 of 10

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Re: [Paul] Sort problem In reply to

I suppose that I should supply more of the relevant code:

Code:


$database='pinball.dat'; 
$databaseview='scores.cgi';  

&parse_form;  

open (FILE,"<$database"); 
@DATAB=<FILE>; 
close (FILE);  

open (DATABASE,">$database"); 
@DB=<DATABASE>; 
 foreach $rec (@DATAB){ 
  chomp($rec); 
  ($name,$company,$score)=split(/\|/,$rec); 
  if ($name eq $input{'name'} && $company eq $input{'company'} && $score eq $input{'score'}){ 
  print DATABASE "$input{'nname'}|$input{'ncompany'}|$input{'nscore'}\n"; 
  }else{ 
  print DATABASE "$name|$company|$score\n"; 
  } 
 } 
close (DATABASE);  

@DATABASE = sort { 
 $score{$b} <=> $score{$a} or $company{$a} cmp $company{$b} or $name{$a} cmp $name{$b} 
} @DATAB;  

foreach $rec (@DATABASE){ 
 chomp($rec); 
 ($name,$company,$score)=split(/\|/,$rec); 
 print DATABASE "$name|$company|$score\n"; 
 }

The different arrays are used in differing parts of the entire program. There are no hashes.

Thanks to all for the input. This is great.

Apr 25, 2003, 12:42 PM

Paul

Veteran (19537 posts)

Apr 25, 2003, 12:42 PM

Post #5 of 10

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Re: [sws_mark] Sort problem In reply to

>>
open (DATABASE,">$database");
@DB=<DATABASE>;
<<

You are opening $database for writing with that command and it will get emptied so @DB will always be empty.

The sort error is partly related to what "Fuzzy Thoughts" said, but also because you are trying to sort on entire un-split lines which sort() won't understand.

Apr 25, 2003, 1:05 PM

sws_mark

New User (4 posts)

Apr 25, 2003, 1:05 PM

Post #6 of 10

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Re: [Paul] Sort problem In reply to

Is my problem possibly also that I am trying to print to a file that is not open?

Apr 25, 2003, 1:47 PM

fuzzy logic

Enthusiast (854 posts)

Apr 25, 2003, 1:47 PM

Post #7 of 10

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Re: [sws_mark] Sort problem In reply to

If you don't mind changing your data structure to an array of hashrefs, then this should help you a little:

Code:
use strict; 
my @data   = (); 

while (my $temp = <DATA>) { 
  chomp $temp; 
  my $rec = {}; 
  ($rec->{name}, $rec->{company}, $rec->{score}) = split /\|/, $temp; 
  push @data, $rec; 
}; 

@data = sort {$b->{score} <=> $a->{score} or $a->{name} cmp $b->{name} or $a->{company} cmp $b->{company}} @data; 

foreach my $rec (@data) { 
  print qq|$rec->{name} : $rec->{company} : $rec->{score}\n|; 
} 

__DATA__ 
foo|bar|7 
foo|bar|5 
foo|bark|6 
blah|bing|3 
this|hack|8 
yack|foo|1 
arg|joo|10

Philip
------------------
Limecat is not pleased.

Apr 25, 2003, 2:12 PM

sws_mark

New User (4 posts)

Apr 25, 2003, 2:12 PM

Post #8 of 10

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Re: [fuzzy thoughts] Sort problem In reply to

Thank you very much.

Apr 25, 2003, 3:28 PM

Paul

Veteran (19537 posts)

Apr 25, 2003, 3:28 PM

Post #9 of 10

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Re: [fuzzy thoughts] Sort problem In reply to

Quote:

($rec->{name}, $rec->{company}, $rec->{score}) = split /\|/, $temp;

Yummy hash slice...

Code:
@rec{qw/name company store/} = split /\|/, $temp;

Apr 25, 2003, 11:09 PM

fuzzy logic

Enthusiast (854 posts)

Apr 25, 2003, 11:09 PM

Post #10 of 10

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Re: [Paul] Sort problem In reply to

I was trying to do that at one point but couldn't remember how. I haven't sat down and written any Perl code in months.

Philip
------------------
Limecat is not pleased.