[29221] in Perl-Users-Digest
Perl-Users Digest, Issue: 465 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue May 29 09:10:17 2007
Date: Tue, 29 May 2007 06:09:07 -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, 29 May 2007 Volume: 11 Number: 465
Today's topics:
(Anno's) "Beyond Inside-Out" <bik.mido@tiscalinet.it>
Re: (Anno's) "Beyond Inside-Out" anno4000@radom.zrz.tu-berlin.de
Beyond Inside-Out anno4000@radom.zrz.tu-berlin.de
Re: FAQ 7.14 How can I pass/return a {Function, FileHan <brian.helterline@hp.com>
find last match in a string? <bugbear@trim_papermule.co.uk_trim>
Re: find last match in a string? <noreply@gunnar.cc>
Re: find last match in a string? <mritty@gmail.com>
Re: find last match in a string? <bugbear@trim_papermule.co.uk_trim>
Re: find last match in a string? <noreply@gunnar.cc>
Re: most active perl discussion forum <bik.mido@tiscalinet.it>
Re: most active perl discussion forum <bik.mido@tiscalinet.it>
PostgreSQL database access <justin.0704@purestblue.com>
Re: PostgreSQL database access <ts@dionic.net>
Re: PostgreSQL database access <mritty@gmail.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Re: The Concepts and Confusions of Prefix, Infix, Postf <etxuwig@cbe.ericsson.se>
Use different modules based on variable <manojkumargupta@gmail.com>
Re: Use different modules based on variable <mritty@gmail.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Tue, 29 May 2007 14:00:48 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: (Anno's) "Beyond Inside-Out"
Message-Id: <1d5o53h5ppgdn0l33b0dv0mmfp32r4kdtu@4ax.com>
Before he does so himself, I put here an "ad" for our Anno's latest
article in PM:
http://perlmonks.org/?node_id=617945
Michele
--
{$_=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: 29 May 2007 12:46:26 GMT
From: anno4000@radom.zrz.tu-berlin.de
Subject: Re: (Anno's) "Beyond Inside-Out"
Message-Id: <5c2ll2F2vdvofU1@mid.dfncis.de>
Michele Dondi <bik.mido@tiscalinet.it> wrote in comp.lang.perl.misc:
> Before he does so himself,
I already did :)
> I put here an "ad" for our Anno's latest
> article in PM:
>
> http://perlmonks.org/?node_id=617945
Thanks!
Anno
------------------------------
Date: 29 May 2007 12:20:02 GMT
From: anno4000@radom.zrz.tu-berlin.de
Subject: Beyond Inside-Out
Message-Id: <5c2k3iF2v7ijoU1@mid.dfncis.de>
I'd like to draw the attention of the group to a writeup of mine
on perlmonks: http://www.perlmonks.org/?node_id=617945
It is about an alternative to the inside-out technique of class
implementation that, I believe, is as powerful in enabling
inheritance, but easier to handle. It comes in the form of
a module named Alter, a preliminary implementation of which
is available at
http://www.tu-berlin.de/zrz/mitarbeiter/anno4000/alter/
Alter exports a function named ego(), which is used to associate
(set and retrieve) an independent piece of data with each object.
The salient point is that the result of the call Alter::ego( $object)
doesn't only depend on $object, but also on the calling class.
Thus, different classes can maintain different views of each
object without getting in each other's way.
Unlike inside-out classes, Alter-based classes don't need extra
support for garbage collection and thread cloning. Like inside-
out, they do need help in serialization. The standard modules
Data::Dumper and Storable don't do anything for them. It seems
possible to provide general inheritable methods for Alter-based
objects to handle these things. This is also something that is
hard to do with inside-out classes.
Anno
------------------------------
Date: Tue, 29 May 2007 00:43:24 -0700
From: Brian Helterlilne <brian.helterline@hp.com>
Subject: Re: FAQ 7.14 How can I pass/return a {Function, FileHandle, Array, Hash, Method, Regex}?
Message-Id: <f3glip$tl2$1@usenet01.boi.hp.com>
PerlFAQ Server wrote:
> This is an excerpt from the latest version perlfaq7.pod, which
> comes with the standard Perl distribution. These postings aim to
> reduce the number of repeated questions as well as allow the community
> to review and update the answers. The latest version of the complete
> perlfaq is at http://faq.perl.org .
>
> --------------------------------------------------------------------
>
> 7.14: How can I pass/return a {Function, FileHandle, Array, Hash, Method, Regex}?
>
> With the exception of regexes, you need to pass references to these
> objects. See "Pass by Reference" in perlsub for this particular
> question, and perlref for information on references.
>
> See "Passing Regexes", later in perlfaq7, for information on passing
> regular expressions.
>
> Passing Variables and Functions
> Regular variables and functions are quite easy to pass: just pass in
> a reference to an existing or anonymous variable or function:
>
> func( \$some_scalar );
>
> func( \@some_array );
> func( [ 1 .. 10 ] );
>
> func( \%some_hash );
> func( { this => 10, that => 20 } );
>
> func( \&some_func );
> func( sub { $_[0] ** $_[1] } );
>
> Passing Filehandles
> As of Perl 5.6, you can represent filehandles with scalar variables
> which you treat as any other scalar.
>
> open my $fh, $filename or die "Cannot open $filename! $!";
> func( $fh );
>
> sub func {
> my $passed_fh = shift;
>
> my $line = <$fh>;
^^^^
while this will work as written, isn't the point to use $passed_fh?
------------------------------
Date: Tue, 29 May 2007 11:26:40 +0100
From: bugbear <bugbear@trim_papermule.co.uk_trim>
Subject: find last match in a string?
Message-Id: <465bffe0$0$8732$ed2619ec@ptn-nntp-reader02.plus.net>
Normally, perl searches left-to-right, and
(consequently) will normally give me
the first match for a regexp in a string.
Is there anyway to get the LAST match?
e.g.
my $a = "abcabd";
$a =~ m/(ab.)/;
print "$1\n";
I'd like (somehow) to get "abd" printed, not "abc"
which is what the above code (obviously) does.
BugBear
------------------------------
Date: Tue, 29 May 2007 12:36:49 +0200
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: find last match in a string?
Message-Id: <5c2e6uF2v404qU1@mid.individual.net>
bugbear wrote:
> Normally, perl searches left-to-right, and
> (consequently) will normally give me
> the first match for a regexp in a string.
>
> Is there anyway to get the LAST match?
>
> e.g.
>
> my $a = "abcabd";
> $a =~ m/(ab.)/;
> print "$1\n";
>
> I'd like (somehow) to get "abd" printed, not "abc"
> which is what the above code (obviously) does.
$a =~ /.*(ab.)/s;
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: 29 May 2007 03:53:42 -0700
From: Paul Lalli <mritty@gmail.com>
Subject: Re: find last match in a string?
Message-Id: <1180436022.050975.29150@w5g2000hsg.googlegroups.com>
On May 29, 6:26 am, bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
> Normally, perl searches left-to-right, and
> (consequently) will normally give me
> the first match for a regexp in a string.
>
> Is there anyway to get the LAST match?
>
> e.g.
>
> my $a = "abcabd";
> $a =~ m/(ab.)/;
> print "$1\n";
>
> I'd like (somehow) to get "abd" printed, not "abc"
> which is what the above code (obviously) does.
Gunnar's solution is the right way to go, IMHO, but in the spirit of
TIMTOWTDI...
$ perl -le'
my $a = "abcabd";
my $last = ($a =~ m/(ab.)/g)[-1];
print $last;
'
abd
Or even...
$ perl -le'
my $a = "abcabd";
(reverse $a) =~ m/(.ba)/;
print scalar reverse $1;
'
abd
Please don't do that, though... icky. :-)
Paul Lalli
------------------------------
Date: Tue, 29 May 2007 13:05:18 +0100
From: bugbear <bugbear@trim_papermule.co.uk_trim>
Subject: Re: find last match in a string?
Message-Id: <465c16ff$0$8715$ed2619ec@ptn-nntp-reader02.plus.net>
Gunnar Hjalmarsson wrote:
> bugbear wrote:
>> Normally, perl searches left-to-right, and
>> (consequently) will normally give me
>> the first match for a regexp in a string.
>>
>> Is there anyway to get the LAST match?
>>
>> e.g.
>>
>> my $a = "abcabd";
>> $a =~ m/(ab.)/;
>> print "$1\n";
>>
>> I'd like (somehow) to get "abd" printed, not "abc"
>> which is what the above code (obviously) does.
>
> $a =~ /.*(ab.)/s;
Are there any performance or memory issues
with this approach if $a is rather large?
(oh, and thanks for replying so fast, and so well)
BugBear
------------------------------
Date: Tue, 29 May 2007 14:39:06 +0200
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: find last match in a string?
Message-Id: <5c2lc8F2ubgkjU1@mid.individual.net>
bugbear wrote:
> Gunnar Hjalmarsson wrote:
>> bugbear wrote:
>>>
>>> my $a = "abcabd";
>>> $a =~ m/(ab.)/;
>>> print "$1\n";
>>>
>>> I'd like (somehow) to get "abd" printed, not "abc"
>>> which is what the above code (obviously) does.
>>
>> $a =~ /.*(ab.)/s;
>
> Are there any performance or memory issues
> with this approach if $a is rather large?
Not that I'm aware of.
Btw, how large is "rather large"?
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: Tue, 29 May 2007 12:21:14 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: most active perl discussion forum
Message-Id: <fivn53p50ec7okhv4i7b4cuk5q22dcpsle@4ax.com>
On Tue, 29 May 2007 04:51:14 +0200, Gunnar Hjalmarsson
<noreply@gunnar.cc> wrote:
>> This newsgroup only has a few posts per day.
>
>While that may be true the past week, clpmisc is usually a high traffic
>newsgroup.
Well, it seems to me that it's been relatively slow for a few weeks. I
don't mind. Generally when it gets really high it is because of flames
or pointless meta-rants or similar stuff.
Michele
--
{$_=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/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Tue, 29 May 2007 12:28:12 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: most active perl discussion forum
Message-Id: <glvn53589oe3fog9v7405pr7mer7jl7ivt@4ax.com>
On Tue, 29 May 2007 01:49:16 GMT, "Greg Benjamin"
<gregben_drop@yahoo.com> wrote:
>This newsgroup only has a few posts per day.
>where is the liveliest perl talk these days?
>I'm a long-time (since about '92) perl user
>and need some help here and there...
I don't thing that traffic activity is the most relevant parameter you
should take into account. It's more a matter of the "philosophy" of
the media. For example, this is *not* a forum at all, it's a
newsgroup. Now, ng's *are* a kind of forum in the widest sense of the
word, but with the latter term people generally mean web-based fora.
By contrast USENET even predates the web itself. So, even if thing
change over time, the respective cultures tend to differ. For example
the typical mentality here is one that occasionally hits on n00bz
nerves, since they perceive it to be overly "elitist" and aimed at
bashing people or boasting rather than actually helping. This is not
the case, but they think so anyway, because they grew up in different
(real and virtual) environments. Some other people would rather prefer
a chat than a ng, a forum or a mailing list. It wholly depends on
one's aptitude. Said this, personally I'm both here and in PerlMonks
which is a very active web based Perl forum with a good reputation.
HTH,
Michele
--
{$_=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, 29 May 2007 12:37:54 -0000
From: Justin C <justin.0704@purestblue.com>
Subject: PostgreSQL database access
Message-Id: <slrnf5o7l2.qsk.justin.0704@stigmata.purestblue.com>
I've a PostgreSQL database that I need to interact with using perl. I
need to be able to add records and amend records only. I'm trying to
find where to start. Searching CPAN for PostgreSQL returns a large list
of modules, I've been through a lot of pages and nothing stands out as
being the/a module that I need. Is there a good reference anywhere, in
simple terms (I've no experience *at all* with databases - but I do have
a book!), that'll tell me which module(s) I need?
Thank you for any help you are able to give.
Justin.
--
Justin C, by the sea.
------------------------------
Date: Tue, 29 May 2007 13:53:53 +0100
From: Tim Southerwood <ts@dionic.net>
Subject: Re: PostgreSQL database access
Message-Id: <465c2261$0$644$5a6aecb4@news.aaisp.net.uk>
Justin C wrote:
> I've a PostgreSQL database that I need to interact with using perl. I
> need to be able to add records and amend records only. I'm trying to
> find where to start. Searching CPAN for PostgreSQL returns a large list
> of modules, I've been through a lot of pages and nothing stands out as
> being the/a module that I need. Is there a good reference anywhere, in
> simple terms (I've no experience *at all* with databases - but I do have
> a book!), that'll tell me which module(s) I need?
>
> Thank you for any help you are able to give.
>
> Justin.
>
Hi
Fortunately, there is only one sane answer:
DBI as the interface module
and DBD::Pg as the driver (there are drivers for most databases which makes
it such a dream).
HTH
Tim
------------------------------
Date: 29 May 2007 05:55:19 -0700
From: Paul Lalli <mritty@gmail.com>
Subject: Re: PostgreSQL database access
Message-Id: <1180443319.180814.270570@p47g2000hsd.googlegroups.com>
On May 29, 8:37 am, Justin C <justin.0...@purestblue.com> wrote:
> I've a PostgreSQL database that I need to interact with using perl. I
> need to be able to add records and amend records only. I'm trying to
> find where to start.
http://dbi.perl.org
http://search.cpan.org/~timb/DBI-1.56/DBI.pm
http://search.cpan.org/~dbdpg/DBD-Pg-1.49/Pg.pm
> Searching CPAN for PostgreSQL returns a large list
> of modules, I've been through a lot of pages and nothing stands out as
> being the/a module that I need. Is there a good reference anywhere, in
> simple terms (I've no experience *at all* with databases - but I do have
> a book!),
Wait, what? You have no experience with databases, but you're trying
to write a script to do database interactivity? You are putting the
cart before the horse. You need to learn about Databases and SQL
before you attempt to do any programming using that database. I
suggest you find a group that will point you towards resources for
learning about these topics, and then once you're comfortable using a
database natively, come back here and read those sites above to learn
how to use that database in a Perl script.
Paul Lalli
------------------------------
Date: 29 May 2007 07:10:20 GMT
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.7 $)
Message-Id: <465bd1db$0$3581$ae4e5890@news.nationwide.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: 1.7 $)
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.augustmail.com/~tadmc/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 <tadmc@augustmail.com> and many others on the
comp.lang.perl.misc newsgroup.
------------------------------
Date: Tue, 29 May 2007 11:13:25 +0200
From: Ulf Wiger <etxuwig@cbe.ericsson.se>
Subject: Re: The Concepts and Confusions of Prefix, Infix, Postfix and Fully Functional Notations
Message-Id: <xczsl9gj8lm.fsf@cbe.ericsson.se>
>>>>> "Jon" == Jon Harrop <jon@ffconsultancy.com> writes:
Jon> Anyway, are there any libraries to do hardware accelerated
Jon> vector graphics in Perl, Python, Lisp, Java or any functional
Jon> language (except OCaml and F# and excluding WPF and
Jon> Silverlight)?
I guess the OpenGL binding for Erlang qualifies. The best
exhibit of this would be Wings3D, an Open Source 3D
graphics modeller, written in Erlang, and with quite a
large user base.
http://www.wings3d.com
BR,
Ulf W
--
Ulf Wiger, Senior Specialist,
/ / / Architecture & Design of Carrier-Class Software
/ / / Team Leader, Software Characteristics
/ / / Ericsson AB, IMS Gateways
------------------------------
Date: 29 May 2007 05:07:07 -0700
From: perlguru <manojkumargupta@gmail.com>
Subject: Use different modules based on variable
Message-Id: <1180440427.754013.224470@q69g2000hsb.googlegroups.com>
This is with respect to a thread "Use different modules based on
variable" <http://groups.google.com/group/comp.lang.perl.misc/
browse_thread/thread/00b9efe4f4416943?tvc=2> .
In this I had suggested for making use of 'require', but that
suggestion was bounced back very badly.
Recently I gave a try, and I see that my suggestion is working :
I created 1st Module 1.1/Test.pm :-
----------------------------------------------------
package Test;
sub func{
print "In 1.1/ \n";
return 1;
}
1;
Created another Module 2.2/Test.pm :-
-----------------------------------------------------------
package Test;
sub func{
print "In 2.2 \n";
return 1;
}
1;
The Main program :-
--------------------------------
#!/usr/bin/perl
$ver=$ARGV[0];
if ( $ver eq '1.1' ){
require "./1.1/Test.pm";
Test::func();
require "./2.2/Test.pm";
Test::func();
}else{
require "./2.2/Test.pm";
Test::func();
require "./1.1/Test.pm";
Test::func();
}
Test::func();
exit 0;
After I executed :-
--------------------------------
$ perl test.pl 1.1
In 1.1/
In 2.2
In 2.2
$ perl test.pl 2.2
In 2.2
In 1.1/
In 1.1/
$ perl test.pl
In 2.2
In 1.1/
In 1.1/
------------End----------------------
I am just a user of Perl, and don't have indepth idea about its
design, And the way its interpreter works.
Would like to know your views, on how is above thing working?
What is dispatch table? And
Why as the per discussion thread
http://groups.google.com/group/comp.lang.perl.misc/browse_thread/thread/00b9efe4f4416943?tvc=2
it shouldnt have been working ?
------------------------------
Date: 29 May 2007 05:50:49 -0700
From: Paul Lalli <mritty@gmail.com>
Subject: Re: Use different modules based on variable
Message-Id: <1180443048.999024.248880@k79g2000hse.googlegroups.com>
On May 29, 8:07 am, perlguru <manojkumargu...@gmail.com> wrote:
> This is with respect to a thread "Use different modules based on
> variable" <http://groups.google.com/group/comp.lang.perl.misc/
> browse_thread/thread/00b9efe4f4416943?tvc=2> .
>
> In this I had suggested for making use of 'require', but that
> suggestion was bounced back very badly.
> Recently I gave a try, and I see that my suggestion is working :
>
> I created 1st Module 1.1/Test.pm :-
> ----------------------------------------------------
> package Test;
>
> sub func{
> print "In 1.1/ \n";
> return 1;
>
> }
>
> 1;
>
> Created another Module 2.2/Test.pm :-
> -----------------------------------------------------------
> package Test;
>
> sub func{
> print "In 2.2 \n";
> return 1;
>
> }
>
> 1;
>
> The Main program :-
> --------------------------------
> #!/usr/bin/perl
>
> $ver=$ARGV[0];
>
> if ( $ver eq '1.1' ){
> require "./1.1/Test.pm";
> Test::func();
> require "./2.2/Test.pm";
> Test::func();}else{
>
> require "./2.2/Test.pm";
> Test::func();
> require "./1.1/Test.pm";
> Test::func();
>
> }
>
> Test::func();
> exit 0;
>
> After I executed :-
> --------------------------------
> $ perl test.pl 1.1
> In 1.1/
> In 2.2
> In 2.2
>
> $ perl test.pl 2.2
> In 2.2
> In 1.1/
> In 1.1/
>
> $ perl test.pl
> In 2.2
> In 1.1/
> In 1.1/
>
> ------------End----------------------
>
> I am just a user of Perl, and don't have indepth idea about its
> design, And the way its interpreter works.
>
> Would like to know your views, on how is above thing working?
> What is dispatch table? And
> Why as the per discussion threadhttp://groups.google.com/group/comp.lang.perl.misc/browse_thread/thre...
> it shouldnt have been working ?
As was said to you in that thread - the same module will NOT be loaded
again. The original requirement was that, at run time, either module
will be needed at any given moment. To illustrate, alter your above
example as follows:
#!/usr/bin/perl
$ver=$ARGV[0];
if ( $ver eq '1.1' ){
require "./1.1/Test.pm";
Test::func();
require "./2.2/Test.pm";
Test::func();
require "./1.1/Test.pm";
Test::func();
}else{
require "./2.2/Test.pm";
Test::func();
require "./1.1/Test.pm";
Test::func();
require "./2.2/Test.pm";
Test::func();
}
Test::func();
exit 0;
$ ./test.pl 1.1
In 1.1/
In 2.2
In 2.2
In 2.2
$ ./test.pl 2.2
In 2.2
In 1.1/
In 1.1/
In 1.1/
Do you see? require() stores the modules that have already been
loaded, and does not load them a second time. The second instance of
either module being require()'d is completely ignored.
That is why your solution was not applicable to the OP's stated goal.
Paul Lalli
------------------------------
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:
#The Perl-Users Digest is a retransmission of the USENET newsgroup
#comp.lang.perl.misc. For subscription or unsubscription requests, send
#the single line:
#
# subscribe perl-users
#or:
# unsubscribe perl-users
#
#to almanac@ruby.oce.orst.edu.
NOTE: due to the current flood of worm email banging on ruby, the smtp
server on ruby has been shut off until further notice.
To submit articles to comp.lang.perl.announce, send your article to
clpa@perl.com.
#To request back copies (available for a week or so), send your request
#to almanac@ruby.oce.orst.edu with the command "send perl-users x.y",
#where x is the volume number and y is the issue number.
#For other requests pertaining to the digest, send mail to
#perl-users-request@ruby.oce.orst.edu. Do not waste your time or mine
#sending perl questions to the -request address, I don't have time to
#answer them even if I did know the answer.
------------------------------
End of Perl-Users Digest V11 Issue 465
**************************************
