Short and Sweet, here's my conundrum:

I'm using Tie::File to open a file, and insert some text after a particular tag. I need to be able to make some decisions though, and in order to do that I need to know what the *next* element in the array is, and act accordingly.

Looking at my copy of the Perl Bookshelf, I'm not finding anything that applies, the closest thing being $#array. I've cribbed my technique from Dominus' treatise on Tie::File, but it's not an exactly parallel task.

Here's the pseudo-code i'm trying to work out: 

### Update the main threads file
tie @threads, 'Tie::File', $main_threads_file or syslog('err', "update
+_threads couldn't open file: $main_threads_file");

if ($thread == $msg_id) {
    # put it right at the top, it's a new thread
    unshift @threads, $link;
} else {
    for (@threads) {
        if (/$parent/) {
            if (##next element is "<ul>"##) {
                #insert $link after the next element (after the <ul>)
            }
            else {
                $_ .= "<ul>";
                ## the next element after that .= $link
                ## the next element after *that* .= "</ul>"
            }
            last;
                
        }
    }
    
}
untie @threads;

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The issue here is that i can't figure out how to say "The element after the current one" or "The second element after the current one".

In reply to Conditonal insert into Array? (Tie::File) by u914

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