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

Hi, I'm trying to expand a directory based on date, log facility, etc. with syslog-ng I have something like 
my @dirs = `ls /var/log/HOSTS/*/*/$year/$month/$day/*`

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which doesn't seem to work, because some of the directories don't exist. I'm sure there's a better way, I'm just to new. Thanks, Harry

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Re: Expanding directories
by grinder (Bishop) on Jun 24, 2002 at 12:13 UTC
    my @dirs = `ls /var/log/HOSTS/*/*/$year/$month/$day/*`

    I'm not sure where you want to go with this, but I assume you want to do something in each directory that exists for the day/month/year for each logged host.

    The canonical Perl way of doing this (without relying on an external program) is to use the venerable File::Find module.

    use File::Find;

find(
  sub {
    return unless
      $File::Find::name =~ m{^/var/log/HOSTS/([^/]+)/([^/]+)/(\d+)/(\d
++)/(\d+)/(.*)$};

    my( $dir1, $dir2, $year, $month, $day, $file ) =
      ( $1,    $2,    $3,    $4,     $5,   $6    );

    # do stuff with $file
  },
  '/var/log/HOSTS'
);

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    Or if you do just want to get the names of the directories that actually exist, you would write something like: 
      $File::Find::name
    =~ m{^/var/log/HOSTS/([^/]+)/([^/]+)/(\d+)/(\d+)/(\d+)$}
      and push, @dirs, $File::Find::name;

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    print@_{sort keys %_},$/if%_=split//,'= & *a?b:e\f/h^h!j+n,o@o;r$s-t%t#u'
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Re: Expanding directories
by bronto (Priest) on Jun 24, 2002 at 10:50 UTC

    Maybe you want something like this:

    @dirs = </var/log/HOSTS/*/*/$year/$month/$day/*>

    Anyway, it's not that "clean", so consider glob or File::Glob. Just do a perldoc -f glob to get some details.

    Ciao!
    --bronto

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      If you check the man page for glob you get:
      Beginning with v5.6.0, this operator is implemented using the standard File::Glob extension

      gav^

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