Thanks ikegami.
But this is a rigorous verdict which marks Tie::File as unusable and not recommendable, right?
Or do you see any serious use cases for it?
Best regards, Karl
«The Crux of the Biscuit is the Apostrophe»
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Or do you see any serious use cases for it?
Dunno, I think that for random access of small files (say, maybe, under a megabyte) in situations where performance is not critical, the ease of implementation can still outweigh the cost. On the other hand, at least in my experience such files are rare. For example, when inserting lines somewhere, one usually has to scan the file to locate the insertion point anyway, so in such cases a while(<>) loop would still feel more natural to me than a linear search in an array. It's maybe a nice module to show off some of the power (Update: as in expressiveness / TIMTOWTDI, not speed) of Perl to newcomers, although then one might cause the problem of "if all you have is a hammer, everything looks like a nail".
Of course ikegami has a good point. There is a huge difference between reading even a ~1MB file into in array, vs. reading it with Tie::File:
$ cp -L /usr/share/dict/words /tmp/test.txt
$ wc -l /tmp/test.txt
99132 /tmp/test.txt
$ du -sh /tmp/test.txt
920K /tmp/test.txt
$ time perl -MTie::File -e 'open F, "/tmp/test.txt" or die;
print `ps -orss $$`; my @x = <F>; print `ps -orss $$`'
RSS
7408
RSS
23604
real 0m0.042s
user 0m0.024s
sys 0m0.012s
$ time perl -MTie::File -e 'tie my @a, "Tie::File", "/tmp/test.txt";
print `ps -orss $$`; $a=$_ for @a; print `ps -orss $$`'
RSS
7612
RSS
55024
real 0m1.001s
user 0m0.908s
sys 0m0.088s
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Didnt you look at the benchmark?
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