gav^

While I agree that File::CounterFile (alt.) is worth using in this instance, it (IIRC) doesn't provide any method for reseting the counter, so your forced to unlink the counter file first, or do something like...

$counter->lock;

$counter->dec while $counter->value > $DEFAULT_VALUE;

$counter->unlock;
[download]

Neither solution seemed all that graceful to me (the latter being quite painful if the current value is of any significance), so I ended up writing a patch to add a reset method ...

sub reset {   
    my($self,$default) = @_;

    $default = $File::CounterFile::DEFAULT_INITIAL 
        unless defined $default;
    
    if ($self->locked) {
        $self->{'value'} = $default;
        $self->{updated} = 1;
    } else {
        $self->lock;
        $self->{'value'} = $default;
        $self->{updated} = 1;
        $self->unlock; 
    }
    $self->{'value'}; # return value
}
[download]

... which'd turn sidhartha's code into ...

#!/usr/bin/perl -w

use strict;
use File::CounterFile;

my $COUNTER       = '/path/to/bg.cnt';
my $DEFAULT_VALUE = 0;

my @BACKGROUND    = qw(
  corner.jpg    anduin.jpg    gandalf.jpg  
  ford.jpg
);

my $c = File::CounterFile->new( $COUNTER, $DEFAULT_VALUE );
   $c->reset if $c->inc > $#BACKGROUND;

print <<EndOfHTML;
Content-type: text/html

<td background="images/$BACKGROUND[$c]">
EndOfHTML
[download]

    --k.

Awesome, I thank all of your for your help.

You can check this using the Cwd module.

#!/usr/bin/perl
use strict;
use CGI;
my $q = new CGI;

use Cwd;
$dir = cwd;

print $q->header('text/plain'),
      $dir;
exit(0);
[download]

My bet is that the current working directory isn't what you think it is when run as a CGI script.

Alternatively, use an absolute path rather than a relative one, ie:

open OUT, ">/path/to/bg.cnt" or die "can't open bg.cnt for writing";
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.02

cLive ;-)

ps - and including $! in the die statment will help - if you put:

use CGI::Carp 'fatalsToBrowser'
[download]

On "missing the obvious", there are several things you can do to help make sure you don't ...

• use strict;
• -w (or use warnings;)
• Including $! in your dies so you know why something couldn't be done.

You might also find Use strict warnings and diagnostics or die a worthwhile read. :)

    --k.

Also wondering why you feel the need to use seek here...looks like it would work identically without it.

--Dave

this is true but i'm using SSI so the images directory is relative to my htdocs directory. thanks for the tip on the seek, i'll see about getting rid of that

The previous posters have covered most of the bases. When you go to try and debug this, keep in mind these specific things to watch/look for:

• The background attribute for the td element should probably be something more like "/images/$background[$cnt]", unless you are certain that the pages using this script (it's clearly an SSI utility) will always be in the directory above that images directory.
• Check the actual path to the counter-file. Or use the File::CounterFile module. The cgi-bin directory might not be where you want this file getting opened.
• Check the UID/GID that the CGI application is running under. Running the script from the command-line as yourself isn't the same as having it run as a CGI under the UID of the web server's process.

--rjray