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Posted by Matt Blasinski on 07/06/05 20:19
I can't believe I'm posting this :-p I'm nowhere near being a
unix/linux guru, and one would probably have a dozen complaints with
this if they saw it, but....
ls -l | grep -v total | cut -f 11 -d ' ' | sort -n | tail -1
Your milage may vary if ls -l displays something slightly different than
mine does, then try adjusting which field cut takes.
HTH,
Matt
Philip Hallstrom wrote:
>> Suppose I have a directory with a HUGE number of filenames, all of which
>> happen to look like integers:
>>
>> ~/nntp/1
>> ~/nntp/2
>> ~/nntp/3
>> .
>> .
>> .
>> ~/nntp/59874
>> ~/nntp/59875
>> ~/nntp/59876
>>
>> Now, in a PHP script, what's the most efficient way to find the "largest"
>> filename, where "largest" means in the sense of an integer, not a string?
>>
>> I could probably force the filenames to be 0-padded if that would make a
>> significant difference.
>>
>> Is there some nifty shell command I should just "exec"?...
>>
>> I don't really care which shell, but I'm a bash user generally.
>>
>> Obviously I could loop through all the filenames, so I'm looking for
>> something faster than that. :-)
>
>
> I can't think of anything you could do in the shell that would be faster...
>
> Anything you do in the shell is going to involve 'ls' which is going to
> have to loop through all the filenames anyway... so you might as well do
> it within PHP and save yourself the exec and other processes to
> sort/trim the list.
>
> I suppose you could try some sort of hunt and peck search... say you had
> some idea how many files where in there (under say 10,000). Then you
> could maybe do something like checking if 5000 exists. If it does,
> check 7500. If it doesn't, check 6250. If it does, check 6875 and so
> on until you're down to a reasonable "gap". Then just check
> incrementally from there.
>
> Whether or not that's going to be faster than just looping through them
> all I don't know...
>
> good luck!
>
> -philip
>
--
Matt Blasinski (mbv)
Information Systems Technology Services Professional
Internet Infrastructure Applications Technology
Division of Information Technology
3228 Computer Science and Statistics
1210 West Dayton Street
Madison WI 53706
Work (608) 263-4865
Personal Cell (608) 347-6940
<?php
echo "You can have it fast, cheap, or working. Choose two.";
?>
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