inman has asked for the wisdom of the Perl Monks concerning the following question:
I am working with a directory that contains both data files and marker files. The marker files have the same base name as the data files but a different extension. They are used as markers that identify the data files that are no longer used. As a result, the files exist as pairs unless they are current in which case only the data file is present. An example directory listing would contain:
00000001.did 00000001.mrg 00000002.did 00000002.mrg 00000003.did
I want to work with all of the current data files so I am using the code below to find the list of data files that does not have a corresponding marker file.
sub unmergedFiles { my $dir = shift; my %merged; my @files; # create the hash containing the merged files foreach (glob ($dir."/*.mrg")) { if ( /(\S+)\.mrg/i ) { $merged{lc ($1 . ".did")} = "1"; } } foreach (glob ($dir."/*.did")) { unless (exists $merged{lc($_)}) { push @files, $_; } } # return style as per node 311537! return wantarray ? @files : \@files; }
This code works just fine but I would like the opinion of more learned monks as to how this code can be improved. A couple of things spring to mind:
- There is probably a CPAN module to do this already but I haven't looked as writing the code was educational.
- I am really just comparing the contents of two arrays to find the difference. Have I missed out on a more concise method?
- I am creating a hash by iterating over an array and assigning new hash elements. Is there a better way of doing this?
All comments gratefully received!
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