[29653] in Perl-Users-Digest
Perl-Users Digest, Issue: 897 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Oct 2 06:09:38 2007
Date: Tue, 2 Oct 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 Tue, 2 Oct 2007 Volume: 11 Number: 897
Today's topics:
Re: all combinations <stoupa@practisoft.cz>
Re: all combinations <bik.mido@tiscalinet.it>
Re: Copy using system <joe@inwap.com>
Re: FAQ 4.52 How do I sort an array by (anything)? <uri@stemsystems.com>
Get unlimited visitors to your website solidsweta@gmail.com
Re: more elegant way to say ($1, $2, $3, $4, ...)? demerphq@gmail.com
Re: more elegant way to say ($1, $2, $3, $4, ...)? demerphq@gmail.com
new CPAN modules on Tue Oct 2 2007 (Randal Schwartz)
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@seesig.invalid
Re: the camel perl book <bik.mido@tiscalinet.it>
Re: the camel perl book <bik.mido@tiscalinet.it>
Re: The Modernization of Emacs: terminology buffer and <gneuner2/@comcast.net>
Re: Trivial? <tony@skelding.co.uk>
Re: Trivial? <tony@skelding.co.uk>
Re: Trivial? <tony@skelding.co.uk>
Re: Using fcntl and |= - "Argument .... isn't numeric i <joe@inwap.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Tue, 2 Oct 2007 06:06:44 +0200
From: "Petr Vileta" <stoupa@practisoft.cz>
Subject: Re: all combinations
Message-Id: <fdsg62$bvj$1@ns.felk.cvut.cz>
Mintcake wrote:
> On Oct 2, 6:49 am, "Petr Vileta" <sto...@practisoft.cz> wrote:
>> I have an array of strings, say
>> @array = ['a','b','c'];
[...]
>> So the result should be
>> @result = [
>> ['a','b','c'],
>> ['a','c','b'],
>> ['b','a','c'],
>> ['b','c','a'],
>> ['c','a','b'],
>> ['c','b','a']
>> ];
>>
> #!/usr/local/bin/perl
>
> use strict;
> use warnings;
>
> my @array = ('a','b','c');
>
> my @result = permute(@array);
>
> print '[' . join(',', map "'$_'", @$_) . "]\n" foreach @result;
>
> sub permute {
> return \@_ if @_ == 1;
> my @result;
> print "@_\n";
> for (my $i = 0; $i < @_; $i++) {
> my @array = @_;
> my $c = splice @array, $i, 1;
> push @result, map [$c, @$_], permute(@array);
> }
> return @result;
> }
--
Thanks a lot for your example. This is exactly what I need.
--
Petr Vileta, Czech republic
(My server rejects all messages from Yahoo and Hotmail. Send me your mail
from another non-spammer site please.)
------------------------------
Date: Tue, 02 Oct 2007 11:33:46 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: all combinations
Message-Id: <c244g3h6h4av07ev89h8p1njfcs541mrdj@4ax.com>
On Tue, 2 Oct 2007 01:49:36 +0200, "Petr Vileta"
<stoupa@practisoft.cz> wrote:
>I have an array of strings, say
>@array = ['a','b','c'];
>and I need to call subroutine or use some module to get array of arrays with
>all possible combinations. Good message is that all strings in @array must
>be used everytime. This reduce number of combinations.
>So the result should be
>@result = [
> ['a','b','c'],
> ['a','c','b'],
> ['b','a','c'],
> ['b','c','a'],
> ['c','a','b'],
> ['c','b','a']
>];
>
>Please can anybody help me to resolve this problem? I'm bad in mathematics
>and I don't know how to ask Google. In other word I'm too stupid to resolve
>this ;-)
These are called *permutations*.
perldoc -q permute
Michele
--
{$_=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/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Mon, 01 Oct 2007 23:54:31 -0700
From: Joe Smith <joe@inwap.com>
Subject: Re: Copy using system
Message-Id: <87ednaHhg4m3dpzanZ2dnUVZ_tijnZ2d@comcast.com>
lerameur wrote:
> system(`cp -p * /dir/$Out_directory/aux `);
>
> I use the above command , the files do get copied, but the command do
> not exit once it is finished. It just hangs there and do not proceed,
> I need to hit ctlr-Z . no error message. what is wrong
We already gave you the answer to your posting of 28 Sep 2007 13:07:08.
(Message-ID: <1191010028.753764.76290@d55g2000hsg.googlegroups.com>)
Were you not paying attention?
You screwed up by using `` instead of "". You need
system("cp -p * /dir/$Out_directory/aux");
or
system("cp -p * /dir/$Out_directory/aux") == 0 or warn
"'cp' failed with error code ",($?>>8),", signal ",($?&0xff);
-Joe
------------------------------
Date: Tue, 02 Oct 2007 05:58:36 GMT
From: Uri Guttman <uri@stemsystems.com>
Subject: Re: FAQ 4.52 How do I sort an array by (anything)?
Message-Id: <x7ir5qhxbn.fsf@mail.sysarch.com>
>>>>> "WJ" == William James <w_a_x_man@yahoo.com> writes:
WJ> On Sep 30, 2:03 pm, PerlFAQ Server <br...@stonehenge.com> wrote:
>> 4.52: How do I sort an array by (anything)?
WJ> [...]
>> which could also be written this way, using a trick that's come to be
>> known as the Schwartzian Transform:
>>
>> @sorted = map { $_->[0] }
>> sort { $a->[1] cmp $b->[1] }
>> map { [ $_, uc( (/\d+\s*(\S+)/)[0]) ] } @data;
>>
WJ> Ruby:
WJ> sorted = data.sort_by{|s| s[ /\d+\s*(\S+)/, 1 ].upcase }
i think this is a little clearer and a lot more flexible. also the GRT
is faster than the ST. dunno what ruby does inside that code.
<untested>
use Sort::Maker ;
my $sorter = make_sorter( 'GRT', 'no_case', string => qr/\d+\s*(\S+)/ ) ;
my @sorted = $sorter->( @data ) ;
uri
--
Uri Guttman ------ uri@stemsystems.com -------- http://www.stemsystems.com
--Perl Consulting, Stem Development, Systems Architecture, Design and Coding-
Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org
------------------------------
Date: Mon, 01 Oct 2007 23:16:59 -0700
From: solidsweta@gmail.com
Subject: Get unlimited visitors to your website
Message-Id: <1191305819.962310.12560@y42g2000hsy.googlegroups.com>
Is your website getting very less no. of visitors .If so, then post
your website to http://goodtolove.com to get unlimited visitors for
lifetime...No need to pay a penny.
------------------------------
Date: Tue, 02 Oct 2007 08:13:54 -0000
From: demerphq@gmail.com
Subject: Re: more elegant way to say ($1, $2, $3, $4, ...)?
Message-Id: <1191312834.823918.161150@o80g2000hse.googlegroups.com>
On Aug 9, 9:08 pm, Uri Guttman <u...@stemsystems.com> wrote:
> >>>>> "L" == Larry <larry.grant...@gmail.com> writes:
>
> L> I'm using a /g regex in a while loop to capture parenthesized matches
> L> to meaningful variable names like this:
>
> L> while (/ (...) ... (...) ... (...)/g) {
> L> my ($foo, $bar, $baz) = ($1, $2, $3);
> L> ...
> L> }
>
> L> The ($1, $2, $3) part seems inelegant ... is there a more elegant way?
>
> you can look at using @+, @- to get the strings via substr. a map call
> on 0 .. $#+ will do it but it is ugly too
>
> perldoc perlvar says this:
> $1 is the same as "substr($var, $-[1], $+[1] - $-[1])"
>
> so this should work (untested):
>
> my ($foo, $bar, $baz) =
> map substr($var, $-[$_], $+[$_] - $-[$_]), 0 .. $#+ ;
>
> and that map stuff could be put into a sub to clean it up. just pass in
> $var and the @+ and @- globals should still be set. something like this:
>
> sub matches {
> map substr($_[0], $-[$_], $+[$_] - $-[$_]), 0 .. $#+ ;
> }
>
> my ($foo, $bar, $baz) = matches( $var ) ;
>
> but i would just stick with the assignment of $1, $2 ... as it is the
> cleanest.
The problem with this approach is that it requires you to know what
string @- and @+ are operating on, which is actually somewhere between
difficult and impossible in the case of s///.
One solution that avoids this problem is the following, somewhat
crufty code:
sub matches { eval 'sub { \@_ }->(' . join(", ", map "\$$_", 1 .. $#
+ ) . ')' }
Now you can say
my $array=matches();
and have it do the right thing always*, even if we didn't make a copy
of the original string before we used s///.
*Of course the array returned for matches() is only "good" for the
results of a given match.
What we (perl5porters) really should do is provide a special magic
variable that returns the entire string that $1 and friends reference,
so then using @- and @+ would be safe. Unfortunately its too late for
that to make it into 5.10, although its possible for 5.10.1 i guess.
Yves
------------------------------
Date: Tue, 02 Oct 2007 08:14:40 -0000
From: demerphq@gmail.com
Subject: Re: more elegant way to say ($1, $2, $3, $4, ...)?
Message-Id: <1191312880.982363.242920@22g2000hsm.googlegroups.com>
On Aug 9, 10:11 pm, Mirco Wahab <wahab-m...@gmx.de> wrote:
> Larry wrote:
> > I'm using a /g regex in a while loop to capture parenthesized matches
> > to meaningful variable names like this:
>
> > while (/ (...) ... (...) ... (...)/g) {
> > my ($foo, $bar, $baz) = ($1, $2, $3);
> > ...
> > }
> > The ($1, $2, $3) part seems inelegant ... is there a more elegant way?
>
> The $n is an idiomatic expression which is
> not that bad in my opinion.
>
> You could fake 'named captures' like this:
Of use 5.10 when it comes out and make use its real named
captures. :-)
Yves
------------------------------
Date: Tue, 2 Oct 2007 04:42:15 GMT
From: merlyn@stonehenge.com (Randal Schwartz)
Subject: new CPAN modules on Tue Oct 2 2007
Message-Id: <Jp9p2F.tD8@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.
Acme-LOLCAT-0.0.1
http://search.cpan.org/~kcowgill/Acme-LOLCAT-0.0.1/
----
Acme-LOLCAT-0.0.2
http://search.cpan.org/~kcowgill/Acme-LOLCAT-0.0.2/
----
Alien-IE7-0.9.1
http://search.cpan.org/~gtermars/Alien-IE7-0.9.1/
installing and finding IE7 JS compatibility library
----
Alien-Lightbox-2.03.3.1
http://search.cpan.org/~gtermars/Alien-Lightbox-2.03.3.1/
installing and finding Lightbox JS
----
Alien-Prototype-Carousel-0.26.1
http://search.cpan.org/~gtermars/Alien-Prototype-Carousel-0.26.1/
installing and finding Prototype Carousel component
----
Alien-Prototype-Window-1.3.1
http://search.cpan.org/~gtermars/Alien-Prototype-Window-1.3.1/
installing and finding Prototype Window Class
----
Alien-scriptaculous-1.7.1.1_03
http://search.cpan.org/~gtermars/Alien-scriptaculous-1.7.1.1_03/
installing and finding script.aculo.us
----
Apache-AppSamurai-1.00
http://search.cpan.org/~pauldoom/Apache-AppSamurai-1.00/
An Authenticating Mod_Perl Front End
----
Atompub-0.2.0
http://search.cpan.org/~takeru/Atompub-0.2.0/
Atom Publishing Protocol implementation
----
CGI-Application-Plugin-TT-LastModified-1.00
http://search.cpan.org/~gtermars/CGI-Application-Plugin-TT-LastModified-1.00/
Set "Last-Modified" header based on TT template
----
Cache-FastMmap-1.20
http://search.cpan.org/~robm/Cache-FastMmap-1.20/
Uses an mmap'ed file to act as a shared memory interprocess cache
----
Class-Dot-1.0.5
http://search.cpan.org/~asksh/Class-Dot-1.0.5/
Simple way of creating accessor methods.
----
Class-Plugin-Util-0.008
http://search.cpan.org/~asksh/Class-Plugin-Util-0.008/
Utility functions for supporting Plug-ins.
----
Class-Root-0.02
http://search.cpan.org/~nif/Class-Root-0.02/
framework for writing perl OO modules
----
Color-Library-0.02
http://search.cpan.org/~rkrimen/Color-Library-0.02/
An easy-to-use and comprehensive named-color library
----
Config-Model-0.613
http://search.cpan.org/~ddumont/Config-Model-0.613/
Model to create configuration validation tool
----
Config-Model-Xorg-0.503
http://search.cpan.org/~ddumont/Config-Model-Xorg-0.503/
Xorg configuration model for Config::Model
----
DBIx-Perlish-0.28
http://search.cpan.org/~gruber/DBIx-Perlish-0.28/
a perlish interface to SQL databases
----
DBM-Deep-1.0005
http://search.cpan.org/~rkinyon/DBM-Deep-1.0005/
A pure perl multi-level hash/array DBM that supports transactions
----
DBM-Deep-1.0006
http://search.cpan.org/~rkinyon/DBM-Deep-1.0006/
A pure perl multi-level hash/array DBM that supports transactions
----
Data-Float-0.006
http://search.cpan.org/~zefram/Data-Float-0.006/
details of the floating point data type
----
Data-Remember-0.01
http://search.cpan.org/~hanenkamp/Data-Remember-0.01/
remember complex information without giving yourself a headache
----
DateTime-Format-Natural-0.53
http://search.cpan.org/~schubiger/DateTime-Format-Natural-0.53/
Create machine readable date/time with natural parsing logic
----
DateTime-TimeZone-0.68
http://search.cpan.org/~drolsky/DateTime-TimeZone-0.68/
Time zone object base class and factory
----
Devel-CheckOS-0.9
http://search.cpan.org/~dcantrell/Devel-CheckOS-0.9/
check what OS we're running on
----
Devel-CheckOS-0.91
http://search.cpan.org/~dcantrell/Devel-CheckOS-0.91/
check what OS we're running on
----
Devel-CheckOS-0.92
http://search.cpan.org/~dcantrell/Devel-CheckOS-0.92/
check what OS we're running on
----
Games-Perlwar-0.03
http://search.cpan.org/~yanick/Games-Perlwar-0.03/
A Perl variant of the classic Corewar game
----
Games-Tournament-Swiss-0.09
http://search.cpan.org/~drbean/Games-Tournament-Swiss-0.09/
FIDE Swiss Same-Rank Contestant Pairing
----
Genezzo-Contrib-Clustered-0.34
http://search.cpan.org/~erollins/Genezzo-Contrib-Clustered-0.34/
Shared data cluster support for Genezzo
----
Geo-GoogleEarth-Document-0.07
http://search.cpan.org/~mrdvt/Geo-GoogleEarth-Document-0.07/
Creates a GoogleEarth KML Document
----
Gungho-0.08008
http://search.cpan.org/~dmaki/Gungho-0.08008/
Yet Another High Performance Web Crawler Framework
----
Gungho-0.08009
http://search.cpan.org/~dmaki/Gungho-0.08009/
Yet Another High Performance Web Crawler Framework
----
HTML-ParagraphSplit-1.05
http://search.cpan.org/~hanenkamp/HTML-ParagraphSplit-1.05/
Change text containing HTML into a formatted HTML fragment
----
Hash-Slice-0.01
http://search.cpan.org/~rkrimen/Hash-Slice-0.01/
Make a hash from a deep slice of another hash
----
KeyedMutex-0.02
http://search.cpan.org/~kazuho/KeyedMutex-0.02/
An interprocess keyed mutex
----
Kvasir-0.05
http://search.cpan.org/~claesjac/Kvasir-0.05/
Generic rule based processing engine
----
Kvasir-Loader-XML-0.01
http://search.cpan.org/~claesjac/Kvasir-Loader-XML-0.01/
Load Kvasir engine declarations in XML
----
Module-Load-0.12
http://search.cpan.org/~kane/Module-Load-0.12/
runtime require of both modules and files
----
Module-MultiConf-0.0301
http://search.cpan.org/~oliver/Module-MultiConf-0.0301/
Configure and validate your app modules in one go
----
Net-Flickr-Backup-2.99
http://search.cpan.org/~ascope/Net-Flickr-Backup-2.99/
OOP for backing up your Flickr photos locally
----
Net-OAuth-0.01
http://search.cpan.org/~kgrennan/Net-OAuth-0.01/
----
Net-Proxy-0.10
http://search.cpan.org/~book/Net-Proxy-0.10/
Framework for proxying network connections in many ways
----
POE-Declarative-0.001
http://search.cpan.org/~hanenkamp/POE-Declarative-0.001/
write POE applications without the mess
----
Parse-Marpa-v0.1_3
http://search.cpan.org/~jkegl/Parse-Marpa-v0.1_3/
Earley's Algorithm, with improvements
----
Parse-Marpa-v0.1_4
http://search.cpan.org/~jkegl/Parse-Marpa-v0.1_4/
Earley's Algorithm, with improvements
----
Parse-Marpa-v0.1_5
http://search.cpan.org/~jkegl/Parse-Marpa-v0.1_5/
Earley's Algorithm, with improvements
----
Pod-WikiDoc-0.18
http://search.cpan.org/~dagolden/Pod-WikiDoc-0.18/
Generate Pod from inline wiki style text
----
QWizard-3.08
http://search.cpan.org/~hardaker/QWizard-3.08/
Display a series of questions, get the answers, and act on the answers.
----
Sendmail_M4.0.26
http://search.cpan.org/~cml/Sendmail_M4.0.26/
----
Sendmail_M4.0.26a
http://search.cpan.org/~cml/Sendmail_M4.0.26a/
----
Swarmage-0.00005
http://search.cpan.org/~dmaki/Swarmage-0.00005/
A Distributed Job Queue
----
Template-Plugin-NoFollow-1.01
http://search.cpan.org/~gtermars/Template-Plugin-NoFollow-1.01/
TT filter to add rel="nofollow" to all HTML links
----
Template-Plugin-TimeDate-1.01
http://search.cpan.org/~gtermars/Template-Plugin-TimeDate-1.01/
TT plugin to parse/format dates using TimeDate
----
Template-Plugin-Trac-1.01
http://search.cpan.org/~gtermars/Template-Plugin-Trac-1.01/
TT filter for Text::Trac
----
TinyAuth-0.96
http://search.cpan.org/~adamk/TinyAuth-0.96/
Extremely light-weight web-based authentication manager
----
Tk-Wizard-2.115
http://search.cpan.org/~mthurn/Tk-Wizard-2.115/
GUI for step-by-step interactive logical process
----
UWO-Student-0.02
http://search.cpan.org/~frequency/UWO-Student-0.02/
Provides Perl object representation of a University of Western Ontario student.
----
WSO2-WSF-Perl-1.0.0
http://search.cpan.org/~chintana/WSO2-WSF-Perl-1.0.0/
----
WWW-Translate-Apertium-0.04
http://search.cpan.org/~enell/WWW-Translate-Apertium-0.04/
Open source machine translation
----
WWW-Translate-Apertium-0.05
http://search.cpan.org/~enell/WWW-Translate-Apertium-0.05/
Open source machine translation
----
WebService-Google-Reader-0.01_2
http://search.cpan.org/~gray/WebService-Google-Reader-0.01_2/
Perl interface for Google Reader
----
forks-0.26
http://search.cpan.org/~rybskej/forks-0.26/
drop-in replacement for Perl threads using fork()
----
forks-BerkeleyDB-0.052
http://search.cpan.org/~rybskej/forks-BerkeleyDB-0.052/
high-performance drop-in replacement for threads
----
rpm-build-perl-0.6.5
http://search.cpan.org/~atourbin/rpm-build-perl-0.6.5/
----
scriptdist-0.15
http://search.cpan.org/~bdfoy/scriptdist-0.15/
create a distribution for a perl script
----
weblint++-1.15
http://search.cpan.org/~bdfoy/weblint++-1.15/
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: Tue, 02 Oct 2007 07:10:24 GMT
From: tadmc@seesig.invalid
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.8 $)
Message-Id: <A9mMi.10099$JD.3591@newssvr21.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
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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
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it's unlikely that you will benefit much from this group.
We're not bossing you around; we're making the point without
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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: Tue, 02 Oct 2007 11:29:08 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: the camel perl book
Message-Id: <rq34g3lcshpg5l1cuhiq4l4oupf45fhkbo@4ax.com>
On Mon, 01 Oct 2007 19:45:08 -0500, "Mumia W."
<paduille.4061.mumia.w+nospam@earthlink.net> wrote:
>> PS.: idea robbed from PM, id://33780
>
>
>What the h*** is this supposed to mean?
http://perlmonks.org/?node_id=33780
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/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Tue, 02 Oct 2007 11:31:19 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: the camel perl book
Message-Id: <9t34g39irfp886sqf9ma30anc2ttu9g3fk@4ax.com>
On Tue, 2 Oct 2007 04:42:45 +0200 (CEST), Jim Cochrane
<allergic-to-spam@no-spam-allowed.org> wrote:
>> Won't that delete all of Ward's files?
>
>Yes - he's (MW) being a meanie.
Yes - but he (WW) appears to be on Windows, so rm -rf is not likely to
do much. Even less so ~.
Michele
--
{$_=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/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Tue, 02 Oct 2007 01:02:29 -0400
From: George Neuner <gneuner2/@comcast.net>
Subject: Re: The Modernization of Emacs: terminology buffer and keybinding
Message-Id: <26k3g39enhpkqdamv6kopiopijotv6v7q6@4ax.com>
On Tue, 02 Oct 2007 03:38:08 GMT, Roedy Green
<see_website@mindprod.com.invalid> wrote:
>On Fri, 28 Sep 2007 18:27:04 -0500, Damien Kick <dkixk@earthlink.net>
>wrote, quoted or indirectly quoted someone who said :
>
>>"free as in beer".
>
>but does not "free beer" nearly always come with a catch or implied
>obligation?
It means you have to bring the chips.
George
--
for email reply remove "/" from address
------------------------------
Date: Mon, 01 Oct 2007 23:44:25 -0700
From: Mintcake <tony@skelding.co.uk>
Subject: Re: Trivial?
Message-Id: <1191307465.793389.323550@n39g2000hsh.googlegroups.com>
On Sep 30, 7:37 am, all mail refused <elvis-85...@notatla.org.uk>
wrote:
> On 2007-09-29, El Bandolero <el_bandol...@libero.it> wrote:
>
> > I'm solving an exercise studying on a tutorial
>
> > The task is to print the (empty or not) lines of a file numbering only the
> > non empty ones.
>
> nl -bt
>
> --
> Elvis Notargiacomo master AT barefaced DOT cheekhttp://www.notatla.org.uk/goen/
That doesn't do the job - it still prints the empty lines it just
doesn't number them
------------------------------
Date: Mon, 01 Oct 2007 23:47:18 -0700
From: Mintcake <tony@skelding.co.uk>
Subject: Re: Trivial?
Message-Id: <1191307638.678122.131990@19g2000hsx.googlegroups.com>
On Sep 29, 1:20 pm, "Mumia W." <paduille.4061.mumia.w
+nos...@earthlink.net> wrote:
> On 09/29/2007 12:39 AM, El Bandolero wrote:
>
> > I'm solving an exercise studying on a tutorial
>
> > The task is to print the (empty or not) lines of a file numbering only the
> > non empty ones.
>
> > How the h### is possible that the following code gives the same result if I
> > change line 9 with the opposite condition?
> > if (!$lines[$i]=="")
>
> > 1 #!/usr/bin/perl
> > 2 #
>
> Put this line near the top of your program:
>
> use warnings;
>
> > 3 $file = 'C:\Perl\html\Artistic.txt';
> > 4 open(PIP, $file);
> > 5 @lines = <PIP>;
> > 6 close(PIP);
> > 7 for ($i=0;$i <= @lines;++$i)
> > 8 {
> > 9 if ($lines[$i]=="")
> > 10 {print $i." ".$lines[$i]};
> > 11 }
>
> The two problems with your program are (1) string comparisons are done
> with 'eq' not '==' and (2) un-chomped blank lines have a single \n
> character in them.
>
> This comparison should work better:
>
> if ($lines[$i] ne "\n")
>
> That line alone won't complete the execise. Depending upon the exercise
> requirements, you may also need another counter ($j). I'll let you
> figure out if that's the case.
What you probably want is more like
if ($lines[$i] =~ /\S/)
After all, if it looks blank it is blank (especially to the tutor)
------------------------------
Date: Tue, 02 Oct 2007 00:44:22 -0700
From: Mintcake <tony@skelding.co.uk>
Subject: Re: Trivial?
Message-Id: <1191311062.824699.32320@o80g2000hse.googlegroups.com>
On Sep 30, 7:37 am, all mail refused <elvis-85...@notatla.org.uk>
wrote:
> On 2007-09-29, El Bandolero <el_bandol...@libero.it> wrote:
>
> > I'm solving an exercise studying on a tutorial
>
> > The task is to print the (empty or not) lines of a file numbering only the
> > non empty ones.
>
> nl -bt
>
> --
> Elvis Notargiacomo master AT barefaced DOT cheekhttp://www.notatla.org.uk/goen/
Apologies - I probably misinterpreted the original posting. nl -bt is
precisely what is required according to requirement - it's just that
the original script was making no attempt whatsoever to print the
blank lines
------------------------------
Date: Tue, 02 Oct 2007 01:02:32 -0700
From: Joe Smith <joe@inwap.com>
Subject: Re: Using fcntl and |= - "Argument .... isn't numeric in bitwise or ..."
Message-Id: <wPKdnZEIRsaBZpzanZ2dnUVZ_hadnZ2d@comcast.com>
Jim Cochrane wrote:
> my $flags = '';
> Argument "" isn't numeric in bitwise or ...
That's because you did not put $flags on the left hand side of
an equal sign. Both undef and '0' are legal for |=, '' is not.
> fcntl($file, F_GETFL, $flags) or die "Could not get flags: $!";
That's not how its documented in "perldoc -f fcntl".
Here's an example of setting a filehandle named "REMOTE" to be
non-blocking at the system level.
use Fcntl qw(F_GETFL F_SETFL O_NONBLOCK);
$flags = fcntl(REMOTE, F_GETFL, 0)
or die "Can't get flags for the socket: $!\n";
$flags = fcntl(REMOTE, F_SETFL, $flags | O_NONBLOCK)
or die "Can't set flags for the socket: $!\n";
That last line in the docs is misleading. It should be:
$value = fcntl(REMOTE, F_SETFL, $flags | O_NONBLOCK)
or die "Can't set flags for the socket: $!\n";
#!/usr/bin/perl
use strict;
use warnings;
use Fcntl;
my $file;
open $file, '>/tmp/test1';
printf "0: O_NONBLOCK = %d = 0x%X, file = %s\n",O_NONBLOCK,O_NONBLOCK,$file;
my $flags;
$flags = fcntl($file, F_GETFL, 0) or die "Could not get flags: $!";
printf "1: flags = 0x%08X\n",$flags;
$flags |= O_NONBLOCK;
printf "2: flags = 0x%08X\n",$flags;
$_ = fcntl($file, F_SETFL, $flags) or die "Could not set flags: $!";
printf "3: value as string = %s\n",$_;
$flags = fcntl($file, F_GETFL, 0) or die "Could not get flags: $!";
printf "4: flags = 0x%08X\n",$flags;
$flags |= 8;
printf "5: flags = 0x%08X\n",$flags;
$_ = fcntl($file, F_SETFL, $flags) or die "Could not set flags: $!";
printf "6: value as string = %s\n",$_;
$flags = fcntl($file, F_GETFL, $flags) or die "Could not get flags: $!";
printf "7: flags = 0x%08X\n",$flags;
print "Setting bit for 8 is ",($flags&8 ? 'supported' : 'not implemented'),
" on $^O\n";
########
0: O_NONBLOCK = 2048 = 0x800, file = GLOB(0x8770c20)
1: flags = 0x00008001
2: flags = 0x00008801
3: value as string = 0 but true
4: flags = 0x00008801
5: flags = 0x00008809
6: value as string = 0 but true
7: flags = 0x00008801
Setting bit for 8 is not implemented on linux
Works as documented.
-Joe
------------------------------
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 897
**************************************
