Re: Finding un-paired files in a directory


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Re: Finding un-paired files in a directory

by Roger (Parson)

on Dec 02, 2003 at 12:10 UTC ( #311589=note: print w/replies, xml )

Need Help??

in reply to Finding un-paired files in a directory

Here's my implementation -

use strict;
use Data::Dumper;

chomp(my @files = <DATA>);

# find unique basenames
my @basenames = keys %{{ map { (split/\./)[0] => 1 } @files }};

# find unpaired files
foreach my $basename (@basenames) {
    my @matches = grep (/$basename/, @files);
    print "$matches[0]\n" if $#matches == 0;
}

__DATA__
00000001.did
00000001.mrg
00000002.did
00000002.mrg
00000003.did
00000004.mrg
[download]

And the output -

00000004.mrg
00000003.did
[download]

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•Re: Re: Finding un-paired files in a directory
by merlyn (Sage) on Dec 02, 2003 at 12:16 UTC

use strict;
use Data::Dumper;

chomp(my @files = <DATA>);

# find unique basenames
my @basenames = keys %{{ map { (split/\./)[0] => 1 } @files }};

# find unpaired files
foreach my $basename (@basenames) {
    my @matches = grep (/$basename/, @files);
    print "$matches[0]\n" if $#matches == 0;
}
[download]

In my opinion, the original solution is actually the most direct, as this is a classic set difference problem.

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

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