If you are running Unix,Linux,etc., and the url is in say the 3rd field (delimited by spaces as you said), then you can use simple shell tools, such as:

cat logfile|awk {'print $3'}|sort|uniq -c > counts.txt
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This is the best approach, however, if your OS does not support such great tools, or you just want a Perl solution, this will work:

$occurences{(split)[2]}++ while (<>);
foreach $url (keys %occurences) {
print "$occurences{$url}\t$url\n";
}
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change the subscript accordingly, then run the program:

<prompt> perl -w programname logfiles
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tigervamp