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

Hi guys,I am new to perl and am having some trouble with the following:

I have a file that has data which looks like:

#12346

orange

#12345

apple

banana

#12344

pear

I need to sort this data according to the numbers in either the same file or another file so that the output looks like the following:

#12344

pear

#12345

apple

banana

#12346

orange

How do I go about this? thanks in advance.

Replies are listed 'Best First'.
Re: Ordering data in a file.
by toolic (Bishop) on Jun 13, 2013 at 01:16 UTC
    Read data into a hash-of arrays data structure, then sort it: 
    use warnings;
use strict;

my %data;
my $key;
while (<DATA>) {
    chomp;
    if (/#(\d+)/) {
        $key = $1;
    }
    else {
        push @{ $data{$key} }, $_;
    }
}

for my $key (sort {$a <=> $b} keys %data) {
    print "#$key\n";
    print "$_\n" for @{ $data{$key} };
    
}
__DATA__
#12346
orange
#12345
apple
banana
#12344
pear

    [download]

[reply]
[d/l]
      Thanks a lot .. it worked instantly!!!
[reply]
Re: Ordering data in a file.
by hippo (Archbishop) on Jun 13, 2013 at 08:47 UTC

    As an old awk head I would first reach for this simple perl-based approach:

    #!/usr/bin/perl

use strict;
use warnings;

$/ = '#';
print sort (<DATA>);

__DATA__
#12346
orange
#12345
apple
banana
#12344
pear

    [download]

    Note that this uses a lexical sort which somewhat coincidentally works for the given data set. If your actual data set is more varied you will probably need to use a different sorting block.

[reply]
[d/l]
Re: Ordering data in a file.
by Anonymous Monk on Jun 13, 2013 at 01:39 UTC
[reply]

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