[26291] in Perl-Users-Digest
Perl-Users Digest, Issue: 8473 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Sep 30 14:05:35 2005
Date: Fri, 30 Sep 2005 11:05:05 -0700 (PDT)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Fri, 30 Sep 2005 Volume: 10 Number: 8473
Today's topics:
Re: ARGV interpretation in s/// <nobull@mail.com>
Re: How do I get more-detailed directory info? <bogus.email@no.spam.com>
Re: string comparison (Anno Siegel)
Re: string matching specific number of times (Anno Siegel)
threads, XSUB allocated memory, destructors, destructio <please_no_mail@zbh.uni-hamburg.de>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 30 Sep 2005 17:21:08 +0100
From: Brian McCauley <nobull@mail.com>
Subject: Re: ARGV interpretation in s///
Message-Id: <dhjolj$2ej$2@redhat2.bham.ac.uk>
Tad McClellan wrote:
> Just in <goth1938@hotmail.com> wrote:
>
>>Problem is that
>>the $[0-9] variables are not being interpreted the way I want them to be.
>
>> s/$Search/$Replace/;
>
>>How can I achieve the desired interpretation of $1?
>
> $Replace = qq("$Replace");
> s/$Search/$Replace/ee;
Once again, can I ask people not post this "simple, obvious, and
wrong"[1] response to this question without mentioning the hazards of
eval() and also pointing out how to avoid the problem with " characters
in $Replace.
[1] http://birmingham.pm.org/talks/faq/Answer.html
------------------------------
Date: Fri, 30 Sep 2005 17:18:51 GMT
From: "Robbie Hatley" <bogus.email@no.spam.com>
Subject: Re: How do I get more-detailed directory info?
Message-Id: <%re%e.3850$KQ5.1876@newssvr12.news.prodigy.com>
Wow, I got more (and more-detailed) responses to this thread
than I had anticpated! Thanks to all who responed. It will
take me a while to digest all the ideas presented.
I haven't had time to follow up on this thread the last couple
days; been busy at work (disentangling 650000 lines of bad
C/C++/Win32api code from a departed (ousted) chief programmer;
an ongoing chore of large magnitude; not as fun as Perl).
A few brief comments:
Jürgen Exner wrote, regarding my use of arrays of hash refs to
emulate C++ list of structs:
> I think that's the most perlish way.
Isn't that supposed to be "Perlescent"? :-)
Dave Weaver wrote:
> If the only thing you're going to do with @files is loop over
> them like this, why bother slurping them into an array in the
> first place? It's better and more scaleable to use something
> like: while( $FileName = readdir( $dir ) {
The info is going to be used more than once, though.
I generally prefer to slurp oft-used data from HD to RAM and
massage it there, rather than hammer the HD with repeated
reads of the same data.
> my ( $mode, $size, $mtime ) = (stat)[ 2, 7, 9 ];
Now that's truly effiecient looking. I think I'll put
something like that in my program.
Paul Lalli wrote:
> my $type = -d _ ? 'dir'
> : -l _ ? 'link'
> : -f _ ? 'file'
> : 'other';
Ok, so that's 3 nested ?: operators; but what's this "_" thing?
Some kind of way of feeding "last referenced file" into the
file-test operators?
> ...include the $! variable in your die()...
What's "$!"? Some sort of "last error" thingy?
(Those last two questions are probably idiotic; but I'm
away from my perl books as I write this or I'd just look
them up.)
I can see I have lots of reading and hacking to do this
weekend. Again, thanks to all who replied to this thread!
Cheers,
Robbie Hatley
------------------------------
Date: 30 Sep 2005 11:48:25 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: string comparison
Message-Id: <dhj8m9$ned$1@mamenchi.zrz.TU-Berlin.DE>
Gunnar Hjalmarsson <noreply@gunnar.cc> wrote in comp.lang.perl.misc:
> Babacio wrote:
> > Shashank Khanvilkar <shashank@mia.ece.uic.edu> writes:
> >>How can i make the below program print "right choice".
> >>
> >>$a = "apple";
> >>
> >>if ($a eq ('apple'|'banana')){
> >> print "right choice\n";
> >>}else{
> >> print "wrong choice\n";
> >>}
> >
> > But if I guess what you really want to do, try that :
> >
> > if ($a eq 'apple' || $a eq 'banana') { etc }
>
> or this:
>
> if ( grep $a eq $_, ('apple', 'banana') ) {
>
> (perldoc -f grep)
...or use Quantum::Superposition
Anno
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------------------------------
Date: 30 Sep 2005 12:29:49 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: string matching specific number of times
Message-Id: <dhjb3t$ned$2@mamenchi.zrz.TU-Berlin.DE>
tester <tester@uussssh.com> wrote in comp.lang.perl.misc:
> Hi All,
>
> My CPU taking 100% if I try to match more than the existing number of
> specific matches in a string. Script is ...
>
> my $something = "this is a test, just test, no kidding, small test, but
> error in test. over over";
> if ($something =~ m/((.*)test(.*)){5}/){
> print "number of matches are 5, successful";
> }
> else{
> print "no 5 matches, failure";
> }
>
> String "test" is repeated only 4 times in $something but if I am trying
> to check whether the $something has 5, my CPU taking 100%. What is the
> issue?
Probably excessive backtracking. Lots of alternatives have already been
proposed.
Anno
--
If you want to post a followup via groups.google.com, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
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------------------------------
Date: Fri, 30 Sep 2005 18:31:09 +0200
From: Andrew Torda <please_no_mail@zbh.uni-hamburg.de>
Subject: threads, XSUB allocated memory, destructors, destruction
Message-Id: <dhjp8d$a4l$1@rzsun03.rrz.uni-hamburg.de>
I have a perl module built out of XSUBs.
The functions malloc() space, build structures and return
pointers to perl. Perl calls their destructor routines with no
problems. The C structures go back to the perl interpreter, as
T_PTROBJ things, specified in a typemap file.
Now, if I use threads, I
make lots of new data
break my arrays into 2 pieces
threads->new( myfunc, @array_to_read_from);
threads->new( myfunc, @array_to_read_from);
thread[0]->join
thread[1]->join
Unfortunately, at the join() stage, each thread decides to
cleanup, and call the destructors for my @array_to_read_from.
Obviously free() gets called multiple times, terrible things
happen to the heap and everything dies.
What should I be doing in my XSUBs when I create objects (really
just pointers to malloc()'d space) to ask perl not to do this ?
I am sure I am missing something obvious, but I cannot find it in
perlxs or perlxstut man pages.
Many thanks for any advice.
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
From: Perl-Users-Request@ruby.oce.orst.edu (Perl-Users-Digest Admin)
Subject: Digest Administrivia (Last modified: 6 Apr 01)
Message-Id: <null>
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End of Perl-Users Digest V10 Issue 8473
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