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Re: Compare the contents of directory with the contents of file

by repson (Chaplain)
on Feb 24, 2001 at 06:55 UTC ( #60600=note: print w/replies, xml ) Need Help??

in reply to Compare the contents of directory with the contents of file

I guess you might be storing the list of contents of a directory in a flat file, and want to check if the current contents differ from the stored record.

In that case I would build a hash of the lines of the file like so:

%files = map { tr/\015\012//d; ($_,1); } (<FILE>);

Where FILE is an already open filehandle.
Then I would loop over the directory like so (where DIR comes from opendir):

while (defined($_ = readdir(DIR))) { next if /^\.\.?$/; unless (delete $files{$_}) { print "New: $_\n"; } }
Reporting things that weren't in the file and removing the others from the hash.
And finally reporting thing from the file that are no longer in the directory:
for (keys %files) { print "Gone: $_\n"; }
Of course if you are not asking for that, then your question needs clarification.

2001-03-04 Edit by Corion : Removed an erroneous <CODE> tag

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[erix]: in this context, one learns all kinds of interesting psychological excuse-jargon: not just 'alternative facts'; how about 'gapped knowledge' ? :)
[erix]: which still manages to sound more or less positive
[Corion]: Huh. I wasn't aware that you cannot segregate Python 2 and Python 3 modules... Hopefully Perl 6 module use C6AN and thus avoid the problem...
[hippo]: I very much hope so.
[moritz]: there are already some (very few) Perl 6 modules on CPAN, but in a way that the p5 indexer avoids them
[hippo]: It's confusing enough to have the Perl6:: namespace which isn't for Perl6 but for features from that ported into Perl.

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