cat /var/log/httpd/access_log | perl -l -a -n -e 'print $F[6]' | sort 
+| uniq -c | sort -n | tail -10
[download]

I'd probably have written that as:

@ARGV = qw(/var/log/httpd/access_log);
my %count;
while (<>) {
  my ($f) = (split)[6];
  $count{$f}++;
}
my $n = 0;
for (sort {$count{$b} <=> $count {$a}) {
  print "$_\n";
  last if ++$n >= 10;
}
[download]

I bet mine runs with 1/4th the CPU.

Except that for small to medium sized files, it doesn't matter and the additional programming (and debugging) time dwarves the running time. And for really long files, your program might actually be slower, or even fail to finish as it will consume significant amounts of memory. The elegant one-liner, consisting of several tools that do one thing well won't suffer from memory problems, as 'sort' knows when to switch to using temporary files.

Having said that, I would have written the one-liner as:

awk '{print $6}' /var/log/httpd/access_log | 
      sort | uniq -c | sort -n | head -10
[download]

I know you're just tossing that code off quickly, but I'm curious to know why you chose to write:

while (<>) {
  my ($f) = (split)[6];
  $count{$f}++;
}
[download]

...rather than...

while (<>) {
  $count{(split)[6]}++;
}
[download]

It makes me wonder if there's some robustness principle at work that eludes me. And of course, there is even...

$count{(split)[6]}++ while <>;
[download]

... but then we are getting into the realms of the cryptic, and I don't seen a more concise way of printing the top N values that doesn't sacrifice economy.

- another intruder with the mooring in the heart of the Perl

TBH I'd lose the Perl altogether:

awk '{ file[$7]++ } END {  for ( v in file ) print file[v], v }' /var/
+log/httpd/access_log | sort -n | tail +10
[download]

I'm sure you could lose the rest of the pipe too but I never got my head around AWK's asort() for cases like this.

/J\

chaining together a few other tools like forking is free

By your reasoning, doing anything with the computer is not free, so why try at all? In my opinion, the cost of something like this is akin to the cost of gum balls: individually, they're so cheap that almost no one has a hard time justifying quantities of less than 100. And if you find yourself arguing with someone over the cost of a gum ball or 1000, just walk away. Your time is better spent.

thor

Feel the white light, the light within
Be your own disciple, fan the sparks of will
For all of us waiting, your kingdom will come

But what draws my attention in these articles is that I never see perl working together with other big ones like awk and bash (, etc.) in LINUX how-tos.

These articles show something from the real LINUX distributions building job experience. There, perl has a significant place and combines well with all the other 'biggies' (just like Mc Giver's swiss-knife). This guy is writing about that point of view. But normally, people just mention perl as a tool or all the others without perl. And it is nice and fair to see them working as a group, don't you think so?

.{\('v')/}   C H E E R   U P !
 _`(___)' ___a_l_b_e_r_t_o_________