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in reply to Resizing MRTG (RRDTool) logs en-masse

my @rrds = grep { /.*rrd$/ && -f "$logsdir/$_" } readdir DIR;

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Why match zero or more characters in  /.*rrd$/ when  /rrd$/ would match the same thing with less work?    Perhaps you meant  /\.rrd$/? 



        $cmd = qq|$mv resize.rrd $logsdir/$rrd|;
        print "\tRenaming resized file, executing $cmd\n";
        system($cmd) == 0 or die "Could not execute $cmd:$!\n";

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Why not just use Perl's built-in rename function? 

        print "\tRenaming resized file, executing $cmd\n";
        rename 'resize.rrd', "$logsdir/$rrd" or die "Could not rename 
+resize.rrd:$!\n";

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Re^2: Resizing MRTG (RRDTool) logs en-masse
by McDarren (Abbot) on Nov 30, 2010 at 01:33 UTC
    Thanks for the feedback, both valid points.

    heh... I completely forgot about the rename function ;-)

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      Also,  /.*rrd$/ will match both of the strings  "rrd" and  "rrd\n" so perhaps you should use  /.*rrd\z/ instead.

      Or perhaps even:  'rrd' eq substr( $_, -3 )

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        It would be pretty unusual to have a file name that ends with \n, so I see that as an edge case that's probably not worth worrying about.

        It's probably better to have a check after the call to RRDs::info, so I've inserted: 

            my $info = RRDs::info "$logsdir/$rrd";
    # Check to ensure we actually have a valid rrd file
    unless ($info->{filename}) {
        print qq|"$logsdir/$rrd" doesn't appear to be a valid rrd log,
+ skipping\n|;
        next;
    }

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        Which does the trick... 
        $ touch foo.rrd

$ ./rrd-resize.pl 
Starting, found 1 rrd files


Processing foo.rrd
"./foo.rrd" doesn't appear to be a valid rrd log, skipping
Finished, processed 1 files in 0.00 seconds

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