[29405] in Perl-Users-Digest
Perl-Users Digest, Issue: 649 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Jul 13 06:09:49 2007
Date: Fri, 13 Jul 2007 03:09:05 -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, 13 Jul 2007 Volume: 11 Number: 649
Today's topics:
Re: "Pop" an alert of some sort in Windows <bik.mido@tiscalinet.it>
Re: "Pop" an alert of some sort in Windows <lambik@kieffer.nl>
[PerlMonks] About List::Util's pure Perl shuffle() <bik.mido@tiscalinet.it>
Re: [PerlMonks] About List::Util's pure Perl shuffle() <bik.mido@tiscalinet.it>
Re: backing up perl <bik.mido@tiscalinet.it>
Re: Life + Perl = Golly (Andrew Trevorrow)
new CPAN modules on Fri Jul 13 2007 (Randal Schwartz)
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@seesig.invalid
Re: re-lurking <bik.mido@tiscalinet.it>
Re: Validation of user provided regex <noreply@gunnar.cc>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 13 Jul 2007 10:58:02 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: "Pop" an alert of some sort in Windows
Message-Id: <lffe93pc439hp6ajp990ggmbmgvp8i2p89@4ax.com>
On Thu, 12 Jul 2007 17:28:05 -0700, RobMay <remay.uk@googlemail.com>
wrote:
>What version of Win32::GUI, and what version of perl? I fixed the
C:\temp>perl -v
This is perl, v5.8.8 built for MSWin32-x86-multi-thread
(with 50 registered patches, see perl -V for more detail)
Copyright 1987-2006, Larry Wall
Binary build 820 [274739] provided by ActiveState
http://www.ActiveState.com
Built Jan 23 2007 15:57:46
C:\temp>perl -MWin32::GUI=99 -e1
Win32::GUI version 99 required--this is only version 1.03 at
C:/Programmi/Perl/l
ib/Exporter/Heavy.pm line 121.
BEGIN failed--compilation aborted.
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Fri, 13 Jul 2007 11:38:21 +0200
From: "Lambik" <lambik@kieffer.nl>
Subject: Re: "Pop" an alert of some sort in Windows
Message-Id: <469747a4$0$37736$5fc3050@dreader2.news.tiscali.nl>
"Michele Dondi" <bik.mido@tiscalinet.it> wrote in message
news:lffe93pc439hp6ajp990ggmbmgvp8i2p89@4ax.com...
> C:\temp>perl -MWin32::GUI=99 -e1
> Win32::GUI version 99 required--this is only version 1.03 at
As Rob has mentioned, the most recent version is 1.05 which you can also get
at Bribes (add http://www.bribes.org/perl/ppm/package.lst to the ppm
repository).
------------------------------
Date: Fri, 13 Jul 2007 11:32:48 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: [PerlMonks] About List::Util's pure Perl shuffle()
Message-Id: <h6he93dt84l5n6bbblqt1n08ci2nt6sfhv@4ax.com>
This is a question of mine I asked in PerlMonks
(<http://perlmonks.org>) that turned into a very interesting
discussion, so interestin IMHO that I feel like reporting it here:
http://perlmonks.org/?node_id=625977
I would like to reproduce the whole thread, but I direct anyone who
could be interested there. For completeness I will adapt to pure text
the original post and paste it hereafter.
---------------------------------------------------------------------
In a recent discussion (<news:f6ofd7$1lf$1@epityr.hut.fi>) in ctt,
PerlTeX was mentioned (and I'm also mentioning it here because it is
not that widely known and IMHO it would deserve being) in relation to
shuffling, at which point in reply to a posted piece of code I wrote
about the
perldoc -q shuffle
FAQ entry, talking in particular about both Fisher-Yates and
List::Util's shuffle(). Now, I happened to check the source code for
the latter module, and since it has pure Perl code for the given
function, I noticed that in particular it is as follows:
sub shuffle (@) {
my @a=\(@_);
my $n;
my $i=@_;
map {
$n = rand($i--);
(${$a[$n]}, $a[$n] = $a[$i])[0];
} @_;
}
Now, at first sight it is a nice piece of Obfu, ain't it? Well, then
if you look at it, it's easy to see how it works and in particular
that it is still Fisher-Yates. But of course you have to think about
it for a while... and I wondered why it is like that...
To be fair, I think that taking references in the first place is to
avoid duplicating data in memory that could be heavy in memory
usage... but then I also thought that all that playing with references
would impose a performance penalty and -for once- I suppose that
performance does matter. So I tried the following Benchmark, comparing
a naive and fairly readable implementation of the algorithm with
List::Util's:
#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw/:all :hireswallclock/;
sub naive (@) {
my @l=@_;
for (reverse 1..$#l) {
my $r=int rand($_+1);
@l[$_,$r]=@l[$r,$_];
}
@l;
}
sub listutil (@) {
my @a=\(@_);
my $n;
my $i=@_;
map {
$n = rand($i--);
(${$a[$n]}, $a[$n] = $a[$i])[0];
} @_;
}
cmpthese -60, { map { $_ => "$_ 1..1000" } qw/naive listutil/ };
__END__
The results are as follows:
C:\temp>perl lus.pl
Rate naive listutil
naive 588/s -- -14%
listutil 684/s 16% --
So that pretty much may answer my question as to why the sub is
implemented like that... but then this raises the question as to how
could one come up with such an idea, because I'm sure I wouldn't
have...
Any comments?
---------------------------------------------------------------------
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Fri, 13 Jul 2007 11:36:49 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: [PerlMonks] About List::Util's pure Perl shuffle()
Message-Id: <imhe93pbc29anbonnkf85p9j6naplcii06@4ax.com>
On Fri, 13 Jul 2007 11:32:48 +0200, Michele Dondi
<bik.mido@tiscalinet.it> wrote:
>I would like to reproduce the whole thread, but I direct anyone who
>could be interested there. For completeness I will adapt to pure text
>the original post and paste it hereafter.
Oh, and at least the first reply
(<http://perlmonks.org/?node_id=626004>), by BrowserUk
(<http://perlmonks.org/?node=BrowserUk>).
---------------------------------------------------------------------
If you accept the principle that code in modules is destined to be
reused in lots of situations, including performance critical ones, and
should therefore do it's utmost to be as efficient as the author is
comfortable maintaining, then List::Util's use of aliasing to sqeeze a
little more performance seems entirely reasonable.
That said, they missed a trick. Using a block form map creates a
additional level of scope that they aren't using and slows
performance.
They can squeeze another 30%, and almost 50% over the 'naive'
implementation, by avoiding it:
sub buk (@) {
my @a = \( @_ );
my $n;
my $i = @_;
map+( $n=rand($i--), ${ $a[ $n ] }, $a[ $n ]=$a[ $i ] )[ 1 ],
@_;
}
cmpthese -1, { map { $_ => "$_ 1..1000" } qw/naive listutil buk/ };
__END__
C:\test>junk
Rate naive listutil buk
naive 520/s -- -13% -32%
listutil 597/s 15% -- -22%
buk 769/s 48% 29% --
---------------------------------------------------------------------
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Fri, 13 Jul 2007 10:59:56 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: backing up perl
Message-Id: <tlfe93lufgsjge4a277jbi58b1t9qmntqs@4ax.com>
On Fri, 13 Jul 2007 02:54:35 +0200, "Petr Vileta"
<stoupa@practisoft.cz> wrote:
>> The default installation is in C:\Perl; I like to put it in
>> C:\Programmi\Perl. "Programmi" is the Italian version of "Program
>> Files".
>>
>This is not good idea ;-) DOS name of this directory will be
>"C:\Progra~1\Perl" and sometime you could have problems. Above this in few
>files in C:\Perl directory is stored this path, e.g. C:\Perl\lib\Config.pm
Never had any problem in *several* years. Actually there are some
occasional issues with some programs and spaces in paths, but the
italian version of "Program Files" does *not* have spaces...
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Fri, 13 Jul 2007 19:57:24 +1000
From: andrew@trevorrow.com (Andrew Trevorrow)
Subject: Re: Life + Perl = Golly
Message-Id: <andrew-1307071957240001@192.168.1.2>
Kent Paul Dolan <xanthian@well.com> wrote:
> Thanks for that, Andrew. I just downloaded it. Now,
> without looking to see if this is there yet, one
> thing I wanted in the previous release was more
> complex selection mechanisms, so that I could
> select, say, a box and then select out the middle,
> or otherwise decorate the Golly universe with a lot
> of disconnected selected areas...
It's in our TODO file so it should happen one day.
> I didn't understand from your writeup: if Golly has
> a "built in" Perl interpreter, why is some external
> Perl environment needed?
Yeh, the term "embedded interpreter" is a bit misleading.
It's the terminology used in "perldoc perlembed" so I just
assumed it would be familiar to Perl users. On Windows
the Perl library -- which implements the interpreter -- is
loaded dynamically (the first time you run a .pl script).
On the Mac and Linux the Perl library is loaded at start
up time. The reasons for the difference are somewhat messy
but hopefully it just works for most people.
Andrew
------------------------------
Date: Fri, 13 Jul 2007 04:42:14 GMT
From: merlyn@stonehenge.com (Randal Schwartz)
Subject: new CPAN modules on Fri Jul 13 2007
Message-Id: <JL3p2E.1rnF@zorch.sf-bay.org>
The following modules have recently been added to or updated in the
Comprehensive Perl Archive Network (CPAN). You can install them using the
instructions in the 'perlmodinstall' page included with your Perl
distribution.
Apache-AxKit-Provider-XMLDOMProvider-0.02
http://search.cpan.org/~jerboaa/Apache-AxKit-Provider-XMLDOMProvider-0.02/
AxKit Provider for remote XML-DOMs available via HTTP
----
Bio-NEXUS-Import-v0.0.2
http://search.cpan.org/~limaone/Bio-NEXUS-Import-v0.0.2/
Extends Bio::NEXUS with parsers for file formats of popular phylogeny programs
----
Bio-Phylo-0.17_RC2
http://search.cpan.org/~rvosa/Bio-Phylo-0.17_RC2/
Phylogenetic analysis using perl.
----
Bio-Phylo-0.17_RC3
http://search.cpan.org/~rvosa/Bio-Phylo-0.17_RC3/
Phylogenetic analysis using perl.
----
Bundle-CGI-Dependencies-0.02
http://search.cpan.org/~ski/Bundle-CGI-Dependencies-0.02/
installs CGI prerequisites
----
Bundle-XML-Devel-0.02
http://search.cpan.org/~ski/Bundle-XML-Devel-0.02/
installs all XML modules and depenedencies
----
CGI-Portal-0.08
http://search.cpan.org/~alpo/CGI-Portal-0.08/
Extensible Framework for Multiuser Applications
----
Carp-REPL-0.08
http://search.cpan.org/~sartak/Carp-REPL-0.08/
read-eval-print-loop on die
----
Carp-REPL-0.09
http://search.cpan.org/~sartak/Carp-REPL-0.09/
read-eval-print-loop on die
----
Catalyst-Model-JabberRPC-0.04
http://search.cpan.org/~fmerges/Catalyst-Model-JabberRPC-0.04/
JabberRPC model class for Catalyst
----
Catalyst-Plugin-Log-Handler-0.07
http://search.cpan.org/~pepe/Catalyst-Plugin-Log-Handler-0.07/
Catalyst Plugin for Log::Handler
----
Catalyst-View-Email-0.02
http://search.cpan.org/~jshirley/Catalyst-View-Email-0.02/
Send Email from Catalyst
----
Data-Password-Check-0.08
http://search.cpan.org/~chisel/Data-Password-Check-0.08/
sanity check passwords
----
Device-MatrixOrbital-GLK-0.01
http://search.cpan.org/~njh/Device-MatrixOrbital-GLK-0.01/
Control the GLK series Matrix Orbital displays
----
Enbugger-0.01
http://search.cpan.org/~jjore/Enbugger-0.01/
Turns the debugger on at runtime.
----
Finance-Math-IRR-0.10
http://search.cpan.org/~erwan/Finance-Math-IRR-0.10/
Calculate the internal rate of return of a cash flow
----
Lingua-YaTeA-0.2
http://search.cpan.org/~thhamon/Lingua-YaTeA-0.2/
Perl extension for extracting terms from a corpus and providing a syntactic analysis in a head-modifier format.
----
Logfile-EPrints-1.10
http://search.cpan.org/~timbrody/Logfile-EPrints-1.10/
Parse Apache logs from GNU EPrints
----
Math-Polynomial-0.04
http://search.cpan.org/~mhasch/Math-Polynomial-0.04/
Perl class for working with polynomials.
----
Module-MultiConf-0.0100_03
http://search.cpan.org/~oliver/Module-MultiConf-0.0100_03/
Configure and validate your app modules in one go
----
MooseX-Method-0.32
http://search.cpan.org/~berle/MooseX-Method-0.32/
Method declaration with type checking
----
Muldis-DB-0.1.0
http://search.cpan.org/~duncand/Muldis-DB-0.1.0/
Full-featured truly relational DBMS in Perl
----
Net-LDAPapi-3.0.0
http://search.cpan.org/~mishikal/Net-LDAPapi-3.0.0/
Perl5 Module Supporting LDAP API
----
PPI-1.199_03
http://search.cpan.org/~adamk/PPI-1.199_03/
Parse, Analyze and Manipulate Perl (without perl)
----
PPI-PowerToys-0.08
http://search.cpan.org/~adamk/PPI-PowerToys-0.08/
A handy collection of small PPI-based utilities
----
Sys-Statistics-Linux-0.12
http://search.cpan.org/~bloonix/Sys-Statistics-Linux-0.12/
Front-end module to collect system statistics
----
Sys-Statistics-Linux-0.13
http://search.cpan.org/~bloonix/Sys-Statistics-Linux-0.13/
Front-end module to collect system statistics
----
Test-Inline-2.204
http://search.cpan.org/~adamk/Test-Inline-2.204/
Lets you put tests in your modules, next to tested code
----
Test-WWW-Mechanize-CGIApp-0.05
http://search.cpan.org/~hartzell/Test-WWW-Mechanize-CGIApp-0.05/
Test::WWW::Mechanize for CGI::Application
----
Weed-0.0079
http://search.cpan.org/~hooo/Weed-0.0079/
Don't use it. It's in development. For test purposes only!
----
XHTML-Instrumented-0.02
http://search.cpan.org/~gam/XHTML-Instrumented-0.02/
packages to control XHTML
----
XHTML-Instrumented-0.03
http://search.cpan.org/~gam/XHTML-Instrumented-0.03/
packages to control XHTML
----
XML-Diff-0.05
http://search.cpan.org/~timm/XML-Diff-0.05/
XML DOM-Tree based Diff & Patch Module
----
XML-Filter-Conditional-0.03
http://search.cpan.org/~pevans/XML-Filter-Conditional-0.03/
an XML SAX filter for conditionally ignoring XML content
----
re-engine-TRE-0.01
http://search.cpan.org/~avar/re-engine-TRE-0.01/
TRE regular expression engine
If you're an author of one of these modules, please submit a detailed
announcement to comp.lang.perl.announce, and we'll pass it along.
This message was generated by a Perl program described in my Linux
Magazine column, which can be found on-line (along with more than
200 other freely available past column articles) at
http://www.stonehenge.com/merlyn/LinuxMag/col82.html
print "Just another Perl hacker," # the original
--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/>
Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!
------------------------------
Date: Fri, 13 Jul 2007 07:10:55 GMT
From: tadmc@seesig.invalid
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.8 $)
Message-Id: <3AFli.2773$eY.2705@newssvr13.news.prodigy.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.8 $)
This newsgroup, commonly called clpmisc, is a technical newsgroup
intended to be used for discussion of Perl related issues (except job
postings), whether it be comments or questions.
As you would expect, clpmisc discussions are usually very technical in
nature and there are conventions for conduct in technical newsgroups
going somewhat beyond those in non-technical newsgroups.
The article at:
http://www.catb.org/~esr/faqs/smart-questions.html
describes how to get answers from technical people in general.
This article describes things that you should, and should not, do to
increase your chances of getting an answer to your Perl question. It is
available in POD, HTML and plain text formats at:
http://www.rehabitation.com/clpmisc.shtml
For more information about netiquette in general, see the "Netiquette
Guidelines" at:
http://andrew2.andrew.cmu.edu/rfc/rfc1855.html
A note to newsgroup "regulars":
Do not use these guidelines as a "license to flame" or other
meanness. It is possible that a poster is unaware of things
discussed here. Give them the benefit of the doubt, and just
help them learn how to post, rather than assume that they do
know and are being the "bad kind" of Lazy.
A note about technical terms used here:
In this document, we use words like "must" and "should" as
they're used in technical conversation (such as you will
encounter in this newsgroup). When we say that you *must* do
something, we mean that if you don't do that something, then
it's unlikely that you will benefit much from this group.
We're not bossing you around; we're making the point without
lots of words.
Do *NOT* send email to the maintainer of these guidelines. It will be
discarded unread. The guidelines belong to the newsgroup so all
discussion should appear in the newsgroup. I am just the secretary that
writes down the consensus of the group.
Before posting to comp.lang.perl.misc
Must
This section describes things that you *must* do before posting to
clpmisc, in order to maximize your chances of getting meaningful replies
to your inquiry and to avoid getting flamed for being lazy and trying to
have others do your work.
The perl distribution includes documentation that is copied to your hard
drive when you install perl. Also installed is a program for looking
things up in that (and other) documentation named 'perldoc'.
You should either find out where the docs got installed on your system,
or use perldoc to find them for you. Type "perldoc perldoc" to learn how
to use perldoc itself. Type "perldoc perl" to start reading Perl's
standard documentation.
Check the Perl Frequently Asked Questions (FAQ)
Checking the FAQ before posting is required in Big 8 newsgroups in
general, there is nothing clpmisc-specific about this requirement.
You are expected to do this in nearly all newsgroups.
You can use the "-q" switch with perldoc to do a word search of the
questions in the Perl FAQs.
Check the other standard Perl docs (*.pod)
The perl distribution comes with much more documentation than is
available for most other newsgroups, so in clpmisc you should also
see if you can find an answer in the other (non-FAQ) standard docs
before posting.
It is *not* required, or even expected, that you actually *read* all of
Perl's standard docs, only that you spend a few minutes searching them
before posting.
Try doing a word-search in the standard docs for some words/phrases
taken from your problem statement or from your very carefully worded
"Subject:" header.
Really Really Should
This section describes things that you *really should* do before posting
to clpmisc.
Lurk for a while before posting
This is very important and expected in all newsgroups. Lurking means
to monitor a newsgroup for a period to become familiar with local
customs. Each newsgroup has specific customs and rituals. Knowing
these before you participate will help avoid embarrassing social
situations. Consider yourself to be a foreigner at first!
Search a Usenet archive
There are tens of thousands of Perl programmers. It is very likely
that your question has already been asked (and answered). See if you
can find where it has already been answered.
One such searchable archive is:
http://groups.google.com/advanced_group_search
If You Like
This section describes things that you *can* do before posting to
clpmisc.
Check Other Resources
You may want to check in books or on web sites to see if you can
find the answer to your question.
But you need to consider the source of such information: there are a
lot of very poor Perl books and web sites, and several good ones
too, of course.
Posting to comp.lang.perl.misc
There can be 200 messages in clpmisc in a single day. Nobody is going to
read every article. They must decide somehow which articles they are
going to read, and which they will skip.
Your post is in competition with 199 other posts. You need to "win"
before a person who can help you will even read your question.
These sections describe how you can help keep your article from being
one of the "skipped" ones.
Is there a better place to ask your question?
Question should be about Perl, not about the application area
It can be difficult to separate out where your problem really is,
but you should make a conscious effort to post to the most
applicable newsgroup. That is, after all, where you are the most
likely to find the people who know how to answer your question.
Being able to "partition" a problem is an essential skill for
effectively troubleshooting programming problems. If you don't get
that right, you end up looking for answers in the wrong places.
It should be understood that you may not know that the root of your
problem is not Perl-related (the two most frequent ones are CGI and
Operating System related), so off-topic postings will happen from
time to time. Be gracious when someone helps you find a better place
to ask your question by pointing you to a more applicable newsgroup.
How to participate (post) in the clpmisc community
Carefully choose the contents of your Subject header
You have 40 precious characters of Subject to win out and be one of
the posts that gets read. Don't waste them. Take care while
composing them, they are the key that opens the door to getting an
answer.
Spend them indicating what aspect of Perl others will find if they
should decide to read your article.
Do not spend them indicating "experience level" (guru, newbie...).
Do not spend them pleading (please read, urgent, help!...).
Do not spend them on non-Subjects (Perl question, one-word
Subject...)
For more information on choosing a Subject see "Choosing Good
Subject Lines":
http://www.cpan.org/authors/id/D/DM/DMR/subjects.post
Part of the beauty of newsgroup dynamics, is that you can contribute
to the community with your very first post! If your choice of
Subject leads a fellow Perler to find the thread you are starting,
then even asking a question helps us all.
Use an effective followup style
When composing a followup, quote only enough text to establish the
context for the comments that you will add. Always indicate who
wrote the quoted material. Never quote an entire article. Never
quote a .signature (unless that is what you are commenting on).
Intersperse your comments *following* each section of quoted text to
which they relate. Unappreciated followup styles are referred to as
"top-posting", "Jeopardy" (because the answer comes before the
question), or "TOFU" (Text Over, Fullquote Under).
Reversing the chronology of the dialog makes it much harder to
understand (some folks won't even read it if written in that style).
For more information on quoting style, see:
http://web.presby.edu/~nnqadmin/nnq/nquote.html
Speak Perl rather than English, when possible
Perl is much more precise than natural language. Saying it in Perl
instead will avoid misunderstanding your question or problem.
Do not say: I have variable with "foo\tbar" in it.
Instead say: I have $var = "foo\tbar", or I have $var = 'foo\tbar',
or I have $var = <DATA> (and show the data line).
Ask perl to help you
You can ask perl itself to help you find common programming mistakes
by doing two things: enable warnings (perldoc warnings) and enable
"strict"ures (perldoc strict).
You should not bother the hundreds/thousands of readers of the
newsgroup without first seeing if a machine can help you find your
problem. It is demeaning to be asked to do the work of a machine. It
will annoy the readers of your article.
You can look up any of the messages that perl might issue to find
out what the message means and how to resolve the potential mistake
(perldoc perldiag). If you would like perl to look them up for you,
you can put "use diagnostics;" near the top of your program.
Do not re-type Perl code
Use copy/paste or your editor's "import" function rather than
attempting to type in your code. If you make a typo you will get
followups about your typos instead of about the question you are
trying to get answered.
Provide enough information
If you do the things in this item, you will have an Extremely Good
chance of getting people to try and help you with your problem!
These features are a really big bonus toward your question winning
out over all of the other posts that you are competing with.
First make a short (less than 20-30 lines) and *complete* program
that illustrates the problem you are having. People should be able
to run your program by copy/pasting the code from your article. (You
will find that doing this step very often reveals your problem
directly. Leading to an answer much more quickly and reliably than
posting to Usenet.)
Describe *precisely* the input to your program. Also provide example
input data for your program. If you need to show file input, use the
__DATA__ token (perldata.pod) to provide the file contents inside of
your Perl program.
Show the output (including the verbatim text of any messages) of
your program.
Describe how you want the output to be different from what you are
getting.
If you have no idea at all of how to code up your situation, be sure
to at least describe the 2 things that you *do* know: input and
desired output.
Do not provide too much information
Do not just post your entire program for debugging. Most especially
do not post someone *else's* entire program.
Do not post binaries, HTML, or MIME
clpmisc is a text only newsgroup. If you have images or binaries
that explain your question, put them in a publically accessible
place (like a Web server) and provide a pointer to that location. If
you include code, cut and paste it directly in the message body.
Don't attach anything to the message. Don't post vcards or HTML.
Many people (and even some Usenet servers) will automatically filter
out such messages. Many people will not be able to easily read your
post. Plain text is something everyone can read.
Social faux pas to avoid
The first two below are symptoms of lots of FAQ asking here in clpmisc.
It happens so often that folks will assume that it is happening yet
again. If you have looked but not found, or found but didn't understand
the docs, say so in your article.
Asking a Frequently Asked Question
It should be understood that you may have missed the applicable FAQ
when you checked, which is not a big deal. But if the Frequently
Asked Question is worded similar to your question, folks will assume
that you did not look at all. Don't become indignant at pointers to
the FAQ, particularly if it solves your problem.
Asking a question easily answered by a cursory doc search
If folks think you have not even tried the obvious step of reading
the docs applicable to your problem, they are likely to become
annoyed.
If you are flamed for not checking when you *did* check, then just
shrug it off (and take the answer that you got).
Asking for emailed answers
Emailed answers benefit one person. Posted answers benefit the
entire community. If folks can take the time to answer your
question, then you can take the time to go get the answer in the
same place where you asked the question.
It is OK to ask for a *copy* of the answer to be emailed, but many
will ignore such requests anyway. If you munge your address, you
should never expect (or ask) to get email in response to a Usenet
post.
Ask the question here, get the answer here (maybe).
Beware of saying "doesn't work"
This is a "red flag" phrase. If you find yourself writing that,
pause and see if you can't describe what is not working without
saying "doesn't work". That is, describe how it is not what you
want.
Sending a "stealth" Cc copy
A "stealth Cc" is when you both email and post a reply without
indicating *in the body* that you are doing so.
Be extra cautious when you get upset
Count to ten before composing a followup when you are upset
This is recommended in all Usenet newsgroups. Here in clpmisc, most
flaming sub-threads are not about any feature of Perl at all! They
are most often for what was seen as a breach of netiquette. If you
have lurked for a bit, then you will know what is expected and won't
make such posts in the first place.
But if you get upset, wait a while before writing your followup. I
recommend waiting at least 30 minutes.
Count to ten after composing and before posting when you are upset
After you have written your followup, wait *another* 30 minutes
before committing yourself by posting it. You cannot take it back
once it has been said.
AUTHOR
Tad McClellan and many others on the comp.lang.perl.misc newsgroup.
--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher\100cmdat/"
------------------------------
Date: Fri, 13 Jul 2007 10:49:45 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: re-lurking
Message-Id: <4qee939iia1lilvnfdt0nanhlg6qllojg0@4ax.com>
On Thu, 12 Jul 2007 18:03:27 -0400, "merl the perl"
<invalid@invalid.net> wrote:
>, with curly braces around the debug expression. Would it, for example, be
>a syntax error if I wrote:
>my $nntp = Net::NNTP->new($SERVER, ( Debug <= 1) );
>, with the arrow operator backwards?
It depends: the "arrow operator backwards" is called "less than or
equal" and makes for valid syntax. But the arrow operator autoquotes
some barewords on its left, <= doesn't. You will still have a
semantical error under strict.pm if you don't have a Debug() sub known
at compile time and with an empty prototype. But the syntax is valid.
>> The curly braces may have been fine: many of Benchmark.pm's functions
>> work like that.
>Where do I find out things about Benchmark.pm ?
perldoc Benchmark
BTW: later I'll post an article touching on that, stay tuned - and
look for a [PerlMonks] "tag", if interested.
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Fri, 13 Jul 2007 06:55:04 +0200
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: Validation of user provided regex
Message-Id: <5fof39F3cnhf0U1@mid.individual.net>
anno4000@radom.zrz.tu-berlin.de wrote:
> Gunnar Hjalmarsson <noreply@gunnar.cc> wrote in comp.lang.perl.misc:
>> In an app where a user may provide a Perl regular expression I want to
>> validate the regex before it's applied. Currently I'm doing something like:
>>
>> {
>> local $SIG{__WARN__} = sub { die $_[0] };
>> eval { $regex = qr($regex) };
>> die $@ if $@;
>> }
>>
>> In other words I rely on Perl's ability to catch errors, where also
>> warnings are treated as errors.
>>
>> Are there other appropriate checks that could be done?
>
> If code interpolations are a possibility, you may want to "use re
> 'eval';" in the block. Or not, depending...
Thanks for the tip, but I really don't see a need for using (?{ ... }),
so I guess I'd better not.
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
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>
Administrivia:
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------------------------------
End of Perl-Users Digest V11 Issue 649
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