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

For reasons similar to "it seems like a good idea" and "why not", I'd like to change the format of a logfile I write to being XML in the next format. But there's a minor problemette.

Normally when I update a logfile I do

open (LOGFILE,">>$logfn"); print LOGFILE, $eventinfo; close (LOGFILE);
which just appends whatever was in $eventinfo to the end of the file. I'd like to do the same thing with the new XML based one which would mean the logfile would look like:
<event time='1234' type='this'> <detail>blah</detail><detail>blahblah</detail> </event> <event time='1236' type='this'> <detail>blah</detail><detail>blahblah</detail> </event> <event time='2234' type='that'> <detail>weeble</detail><detail>blahblah</detail> </event>
Unfortunately if I try to use XML::Simple (or any other XML reader come to think of it) to process the logfile as is it barfs because there are no <rootelement></rootelement> tags surrounding the event list.

Clearly the starting <rootelement> tag is easy to insert in the logfile. My problem is the final </rootelement> tag because what I need to do is overwrite that with $eventinfo.'<rootelement>' and when you open using append you can't do this.

It seems to me an alternative would be to provide the XML::Simple reader with fake <rootelement> tags, but there doesn't seem to be a way to do this without reading the whole file in once anyway which could be messy if it gets large.

Anyone got any suggestions other than using open(LOGFILE, "+<$logfn") and some horrible "seek"ing?


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