Re: Extracting information from file to Hash

[tobyink]

Here's a quick stab at a solution. It works with your example data...

use strict;
use Data::Dumper;

my %hash;
my $regexp = qr{
    ^ \s*
        Collection \s* => \s* (\d+)? \s*
        ImageCount \s* => \s* (\d+)? \s*
        Status     \s* => \s* (\w+)? \s*
        Missing    \s* => \s* ([\d,]+)? \s*
        Modified   \s* => \s* ([\d/]+\s[\d:]+)? \s*
    $}x;

while (defined(my $line = <DATA>))
{
    chomp $line;
    my %linehash;
    if ($line =~ $regexp)
    {
        %linehash = ( 
            Collection   => $1,
            ImageCount   => $2,
            Status       => $3,
            Missing      => $4,
            Modified     => $5,
            );
    }
    next unless defined $linehash{Collection};
    $hash{ $linehash{Collection} } = \%linehash;
}

my @sorted_by_status = sort { $a->{Status} cmp $b->{Status} } values %
+hash;

print Dumper \@sorted_by_status;

__DATA__
Collection=>168245 ImageCount=>6 Status=>SI Missing=>1,3 Modified=>01/
+18/2012 11:14:30
Collection=>161745 ImageCount=>6 Status=>I Missing=>2,3 Modified=>01/1
+8/2012 11:16:38
Collection=>162451 ImageCount=>6 Status=>SC Missing=> Modified=>01/20/
+2012 11:16:38
Collection=>117481 ImageCount=>8 Status=>C Missing=> Modified=>01/18/2
+011 7:16:38

It would be nice if the regular expression could be made less specific, but some features of your data format make that tricky (e.g. the fact that the value following "=>" can be a zero-length string).

[bart]

It would be nice if the regular expression could be made less specific, but some features of your data format make that tricky (e.g. the fact that the value following "=>" can be a zero-length string).

However, I think it's pretty much guaranteed that there will be whitespace between the key/value pairs. Yet, you use /\s*/. Also, nowhere do I see specified that there even may be whitespace around the "=>" — you just made that up. As this file looks to be computer generated, I sincerely doubt that this will ever be the case. Finally: the only place do I see whitespace inside a column value, is in the final column of the line: the timestamp.

In short: I think this regex will do:

/^Collection=>(\S*) \s+ 
  ImageCount=>(\S*) \s+
  Status=>(\S*) \s+
  Missing=>(\S*) \s+
  Modified=>(.*\S) /x

And if you do this:

my %r = 
    /^ (Collection)=>(\S*) \s+ 
       (ImageCount)=>(\S*) \s+
       (Status)=>(\S*) \s+
       (Missing)=>(\S*) \s+
       (Modified)=>(.*\S)
    /x;

you even get a nice hash record out of it, even though it is restricted to one match per line (otherwise, when using /g you'd get list context, with a different behavior as a result.