[25233] in Perl-Users-Digest
Perl-Users Digest, Issue: 7478 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Dec 3 06:05:55 2004
Date: Fri, 3 Dec 2004 03:05:12 -0800 (PST)
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, 3 Dec 2004 Volume: 10 Number: 7478
Today's topics:
(beginner question) downsample data points using chaine (Oscar Stiffelman)
Re: [Proposal] Q: RE lexical scopes and sub declaration <bik.mido@tiscalinet.it>
Re: [Proposal] Q: RE lexical scopes and sub declaration <bik.mido@tiscalinet.it>
FAQ 1.8: Is Perl difficult to learn? <comdog@panix.com>
FAQ 8.22: Why do setuid perl scripts complain about ker <comdog@panix.com>
Re: make this more efficient? <zen13097@zen.co.uk>
Re: parent of an orphaned process-info about perl and O madhav_a_kelkar@hotmail.com
Re: Perl / MySql / Shopping cart <nospam@bigpond.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Question for Tassilo <socyl@987jk.com.invalid>
Re: Question for Tassilo <tassilo.von.parseval@rwth-aachen.de>
Re: Reference to hash and array <corleone@godfather.com>
Re: testing for existence of an inline file with Inline <tadmc@augustmail.com>
The Perl Review, Winter 2004 <comdog@panix.com>
Re: The Perl Review, Winter 2004 <bigiain@mightymedia.com.au>
Re: The Perl Review, Winter 2004 <comdog@panix.com>
vbscript or perl <gyruss@hushmail.com>
Re: vbscript or perl <amead@comcast.net>
Re: vbscript or perl <pDOTpagel@gsf.de>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: 2 Dec 2004 19:30:35 -0800
From: imagine@gmail.com (Oscar Stiffelman)
Subject: (beginner question) downsample data points using chained maps
Message-Id: <a6aad5c7.0412021930.3f162253@posting.google.com>
I have a vector of numeric points specified as 2 cols in a text file.
I want to break the points into windows and compute averages for each
window.
And (this is important), I am looking for a compact perlish way to do
it, ideally using the more "functional programming" parts of the
language, as opposed to the direct, nested for loops.
I am new to Perl, so I would appreciate feedback on the approach I
have taken below.
#!/usr/bin/perl
$w = shift; # this is the block size
die "must specify window size" if !$w;
@x = sort {@$a[0] <=> @$b[0]} map {[split]} <>;
print "@$_\n" for map {
($s0,$s1)=(0,0);
for(@$_) {
$s0 += @$_[0];
$s1 += @$_[1]
};
[$s0/$w, $s1/$w]
} map {
[@x[$_*$w .. ($_+1)*$w-1]]
} (0..$#x/$w);
# In pseudocode, this is what it does:
for(i = 0; i < n; i+= width) {
(x,y) = (0,0);
for(int j = 0; j < width; j++) {
x += vec[i+j][0];
y += vec[i+j][1];
}
push results, [x/width, y/width];
}
Can anyone suggest an even more compact or idiomatically-correct way
to do this?
P.S.,
I am evaluating using Perl to do some of the data manipulation and
analysis that I currently perform in Mathematica. In Mathematica,
lisp-ish mapping of anonymous functions is really common (and
convenient), so I am trying to decide if similar transformations can
be expressed compactly in perl.
------------------------------
Date: Fri, 03 Dec 2004 09:11:27 +0100
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: [Proposal] Q: RE lexical scopes and sub declarations
Message-Id: <9p60r01aam09bcp8gqsp176efki3js95gj@4ax.com>
On 2 Dec 2004 21:50:55 GMT, anno4000@lublin.zrz.tu-berlin.de (Anno
Siegel) wrote:
>You mean you want to declare a lexical variable in one block, and use
>it in another? Oh boy, is that wrong! It breaks the concept of lexical
Yep!
>scope, in a long-distance way. I don't think you'll find fans on p5p
>for this.
I understand that... however I would consider that a sort of lexical
scope exportation rather than a breakdown: actually it would be just
the same, but with a better name! Seriously I think that as far as the
declaration part is concerned, the particular syntax would stress well
enough what's going on. OTOH I realize that as for the definition part
there may be in fact variables whose source could be hard to track
down thus degradating code intellegibility and maintainability. Maybe
a slightly more acceptable option would be to require a particular
pragma to activate the feature, a la
sub {
use declarationscope;
print $var1;
# ...
}
Michele
--
{$_=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, 03 Dec 2004 09:11:29 +0100
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: [Proposal] Q: RE lexical scopes and sub declarations
Message-Id: <ra70r0pvfiujjsntenc8arq94t6p5juttr@4ax.com>
On Thu, 2 Dec 2004 16:48:00 -0600, Tad McClellan
<tadmc@augustmail.com> wrote:
>I thought so because you can use a vanilla forward declaration
>along with the more proper closure that you had presented.
>
> sub foo;
>
> ...
>
> { my $foovar;
> sub foo { ... }
> }
I don't think it is *exactly* so. Granted: I don't think this would be
a feature one can't leave without. In fact I've been programming in
Perl for a relatively long time now and I've never ever felt the need
for it up until the other day...
To be fair the more I think of it, I realize that the many different
ways to do it in current code are not just as bad as they seemed to me
in that moment. However, for some reason that due to time restriction
I can't explain here in detail, it would have been sensible for
intelligibility matters to "put" that var near the top of the source,
then go on with the main program itself which is only a limited number
of lines, and following it with a moderately long series of subs. As I
said I'm not so much convinced about this any more. But if one really
wanted...
Michele
--
{$_=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, 3 Dec 2004 11:03:01 +0000 (UTC)
From: PerlFAQ Server <comdog@panix.com>
Subject: FAQ 1.8: Is Perl difficult to learn?
Message-Id: <coph55$5g4$1@reader1.panix.com>
This message is one of several periodic postings to comp.lang.perl.misc
intended to make it easier for perl programmers to find answers to
common questions. The core of this message represents an excerpt
from the documentation provided with Perl.
--------------------------------------------------------------------
1.8: Is Perl difficult to learn?
No, Perl is easy to start learning--and easy to keep learning. It looks
like most programming languages you're likely to have experience with,
so if you've ever written a C program, an awk script, a shell script, or
even a BASIC program, you're already partway there.
Most tasks only require a small subset of the Perl language. One of the
guiding mottos for Perl development is "there's more than one way to do
it" (TMTOWTDI, sometimes pronounced "tim toady"). Perl's learning curve
is therefore shallow (easy to learn) and long (there's a whole lot you
can do if you really want).
Finally, because Perl is frequently (but not always, and certainly not
by definition) an interpreted language, you can write your programs and
test them without an intermediate compilation step, allowing you to
experiment and test/debug quickly and easily. This ease of
experimentation flattens the learning curve even more.
Things that make Perl easier to learn: Unix experience, almost any kind
of programming experience, an understanding of regular expressions, and
the ability to understand other people's code. If there's something you
need to do, then it's probably already been done, and a working example
is usually available for free. Don't forget the new perl modules,
either. They're discussed in Part 3 of this FAQ, along with CPAN, which
is discussed in Part 2.
--------------------------------------------------------------------
Documents such as this have been called "Answers to Frequently
Asked Questions" or FAQ for short. They represent an important
part of the Usenet tradition. They serve to reduce the volume of
redundant traffic on a news group by providing quality answers to
questions that keep coming up.
If you are some how irritated by seeing these postings you are free
to ignore them or add the sender to your killfile. If you find
errors or other problems with these postings please send corrections
or comments to the posting email address or to the maintainers as
directed in the perlfaq manual page.
Note that the FAQ text posted by this server may have been modified
from that distributed in the stable Perl release. It may have been
edited to reflect the additions, changes and corrections provided
by respondents, reviewers, and critics to previous postings of
these FAQ. Complete text of these FAQ are available on request.
The perlfaq manual page contains the following copyright notice.
AUTHOR AND COPYRIGHT
Copyright (c) 1997-2002 Tom Christiansen and Nathan
Torkington, and other contributors as noted. All rights
reserved.
This posting is provided in the hope that it will be useful but
does not represent a commitment or contract of any kind on the part
of the contributers, authors or their agents.
------------------------------
Date: Fri, 3 Dec 2004 05:03:00 +0000 (UTC)
From: PerlFAQ Server <comdog@panix.com>
Subject: FAQ 8.22: Why do setuid perl scripts complain about kernel problems?
Message-Id: <coos24$t44$1@reader1.panix.com>
This message is one of several periodic postings to comp.lang.perl.misc
intended to make it easier for perl programmers to find answers to
common questions. The core of this message represents an excerpt
from the documentation provided with Perl.
--------------------------------------------------------------------
8.22: Why do setuid perl scripts complain about kernel problems?
Some operating systems have bugs in the kernel that make setuid scripts
inherently insecure. Perl gives you a number of options (described in
perlsec) to work around such systems.
--------------------------------------------------------------------
Documents such as this have been called "Answers to Frequently
Asked Questions" or FAQ for short. They represent an important
part of the Usenet tradition. They serve to reduce the volume of
redundant traffic on a news group by providing quality answers to
questions that keep coming up.
If you are some how irritated by seeing these postings you are free
to ignore them or add the sender to your killfile. If you find
errors or other problems with these postings please send corrections
or comments to the posting email address or to the maintainers as
directed in the perlfaq manual page.
Note that the FAQ text posted by this server may have been modified
from that distributed in the stable Perl release. It may have been
edited to reflect the additions, changes and corrections provided
by respondents, reviewers, and critics to previous postings of
these FAQ. Complete text of these FAQ are available on request.
The perlfaq manual page contains the following copyright notice.
AUTHOR AND COPYRIGHT
Copyright (c) 1997-2002 Tom Christiansen and Nathan
Torkington, and other contributors as noted. All rights
reserved.
This posting is provided in the hope that it will be useful but
does not represent a commitment or contract of any kind on the part
of the contributers, authors or their agents.
------------------------------
Date: 03 Dec 2004 09:20:45 GMT
From: Dave Weaver <zen13097@zen.co.uk>
Subject: Re: make this more efficient?
Message-Id: <41b02fed$0$1063$db0fefd9@news.zen.co.uk>
On Wed, 01 Dec 2004 01:26:05 GMT, roach <joey01@cfl.rr.com> wrote:
> Is there a more efficient way to do the following code?
-- <snip> --
1. use strict & warnings to get the most help you can from perl.
2. why create a 2nd file just to split the input into 144-byte chunks
when you can use $/ to do that for you?
3. lots of if ... elsif statements suggest a lookup table.
Something like (untested) :
#!/usr/bin/perl
use strict;
use warnings;
my %levels = (
NNNRRRNRRNRRNNNNNNNNRRNNNWNNNNNNNNNNNNNNNNNNNNNNNNRNN0NNRNNN => 8,
NNNNNWNWWWNNNNNWNNNNRNNNNWNNNNNNNNNNNNNNNNNNNNNNNNRNN0NNRNNN => 7,
# etc..
);
{
local $/ = \144;
open my $fs, 'FS' or die "Can't open 'FS' : $!";
while ( <$fs> ) {
my $switches = substr( $_, 70, 60 );
my $level = $levels{ $switches } || 'NONE';
print "$_ $level\n";
}
}
------------------------------
Date: 2 Dec 2004 21:07:36 -0800
From: madhav_a_kelkar@hotmail.com
Subject: Re: parent of an orphaned process-info about perl and OS version.
Message-Id: <338e571.0412022107.4f2544c5@posting.google.com>
Darren Dunham <ddunham@redwood.taos.com> wrote in message news:<jfJrd.37332$6q2.34133@newssvr14.news.prodigy.com>...
> madhav_a_kelkar@hotmail.com wrote:
> > Hi,
>
> > I am using perl 5.8.0 compiled with threads. I am using Linux
> > Redhat 9.0. Is there anything else that you may need?
>
> Posting a followup in the same thread with the same subject makes it
> much easier to follow.
>
> getppid doesn't return a dynamic value under linux with a threaded
> perl.
>
> Read this thread. Linux::Pid might be useful for you.
> http://aspn.activestate.com/ASPN/Mail/Message/perl5-porters/2168829
Thanks a lot for this information. I apologise to all for posting the
message in wrong thread.
Reagards,
Madhav.
------------------------------
Date: Fri, 03 Dec 2004 12:42:59 +1000
From: Gregory Toomey <nospam@bigpond.com>
Subject: Re: Perl / MySql / Shopping cart
Message-Id: <31a25qF39i01hU1@individual.net>
Tony M M wrote:
>
> Has anyone on this message group ever thought of modifying, or building a
> shopping cart that is real world and usable then putting it out to the
> populous?
>
> What I see is bloated, non working perl scripts that are missing the mark
> in the area.
There are a few ones like http://www.ratite.com/Perl/WebStore.shtml
However most LAMP shopping cards tend to be php eg oscommerce
> I see one script that seems like a perfect starting point but needs to be
> developed and a simple hack like I am is unable to get it to interact with
> a real time credit card processor. (
> http://www.digitalpressworks.com/shoppingcart.html )
>
> That is a great starting point with the cart. After that it needs two
> types of things to be built -- accounting and inventory ability (using
> MySql).
>
> I asked this question after looking at perl shopping carts for the last 6
> months and seeing what I indicated above.... If this has been tackled in
> the past could anyone point me to the thread? If not, is this the type of
> newsgroup that participates like this?
>
> Thank you,
>
> Tony <Mike> M.
I didnt like anything I saw so I rolled my own.
It took me about a month to write Phase 1 of www.pchq.com.au in Perl/mysql,
complete with an interface to a wholesaler to automatically update prices.
I added a Perl html whitespace remover and installed a Squid reverse proxy
so hopefully the site loads fast. Graphics are done with ImageMagick.
Phase 2 will add checkout/credit card payments.
gtoomey
------------------------------
Date: 03 Dec 2004 08:22:28 GMT
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.5 $)
Message-Id: <41b02243$0$27769$8b463f8a@news.nationwide.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.5 $)
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://mail.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
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: Fri, 3 Dec 2004 04:20:31 +0000 (UTC)
From: kj <socyl@987jk.com.invalid>
Subject: Question for Tassilo
Message-Id: <coopif$sc7$1@reader1.panix.com>
In <slrncqj3p5.2r7.tassilo.von.parseval@localhost.localdomain> "Tassilo v. Parseval" <tassilo.von.parseval@rwth-aachen.de> writes:
>So Python looks appealing to you? Well, learn it, try to understand some
>largish projects implemented in Python and come back. Just as Perl (and
>certainly any language), it has flaws. As it happens, the Pythonic flaws
^^^^^^^^^^^^^^^^^^
>can be a real spoiler when it comes to large projects in particular. It
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>has quite a few inconsistencies, too...
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>Ruby on the other hand is quite a different beast. With a Perl
>background, it's fairly easy to pick up. In many ways it ressembles
>Perl. The superficial programmer will see with delight that its syntax
>is less intimidating than that of Perl. On the surface, it ressembles
>Python, structurally however it's much closer to Perl. In that, it
>avoids most of Python's serious shortcomings for
^^^^^^^^^^^^^^^^^^^^^^^^
>programming-in-the-large.
^^^^^^^^^^^^^^^^^^^^^^^^^
Tassilo, care to elaborate on what these inconsistencies and flaws
are? (Or could you point me to where I can read about them?)
Thanks,
kj
--
NOTE: In my address everything before the first period is backwards;
and the last period, and everything after it, should be discarded.
------------------------------
Date: Fri, 3 Dec 2004 09:07:11 +0100
From: "Tassilo v. Parseval" <tassilo.von.parseval@rwth-aachen.de>
Subject: Re: Question for Tassilo
Message-Id: <slrncr07lf.ra.tassilo.von.parseval@localhost.localdomain>
Also sprach kj:
> In <slrncqj3p5.2r7.tassilo.von.parseval@localhost.localdomain> "Tassilo v. Parseval" <tassilo.von.parseval@rwth-aachen.de> writes:
>
>>So Python looks appealing to you? Well, learn it, try to understand some
>>largish projects implemented in Python and come back. Just as Perl (and
>>certainly any language), it has flaws. As it happens, the Pythonic flaws
> ^^^^^^^^^^^^^^^^^^
>>can be a real spoiler when it comes to large projects in particular. It
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>has quite a few inconsistencies, too...
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>Ruby on the other hand is quite a different beast. With a Perl
>>background, it's fairly easy to pick up. In many ways it ressembles
>>Perl. The superficial programmer will see with delight that its syntax
>>is less intimidating than that of Perl. On the surface, it ressembles
>>Python, structurally however it's much closer to Perl. In that, it
>>avoids most of Python's serious shortcomings for
> ^^^^^^^^^^^^^^^^^^^^^^^^
>>programming-in-the-large.
> ^^^^^^^^^^^^^^^^^^^^^^^^^
>
> Tassilo, care to elaborate on what these inconsistencies and flaws
> are? (Or could you point me to where I can read about them?)
I've been unable to find this specific article I had in mind. It was a
longish report on various kinds of problems they had with Python in
their company. Some of then seemed to arise from the fact that several
people were working simultaneously on large programs (the common
scenario in the design and implementation of large projects). In
particular, a whole team of programmers was kept busy hunting down a bug
for over a week. The problem eventually turned out to be a trivial typo
of a variable name.
There's an interesting inconsistency in Python with respect to enforcing
certain rules. There are kinds of such enforcements, most notably in the
way source codes needs to be formatted. I am not one of those who thinks
the whitespace-awareness of Python is the real glitch. What I however do
find strange is that no such discipline & bondage measures exist for the
handling of variables. The bug mentioned above would have never been
possible if there had been a way to put Python in a mode that would
disallow using non-declared variables. The Pythoners argue that this is
no problem because their language barfs when accessing an uninitialized
variable. Yet, this is only true for half of the cases: You may still
assign to any variable:
tmpVar = function()
...
tmpvar = another_function()
# too bad, tmpVar still has its old value
print tmpVar
The other common suggestion to catch those cases are external tools such
as pylint etc. These tools become less and less practical when a program
grows. And incidentally, they weren't able to detect the above problem in
this company.
There is more. You may not yet have heard of Python's spiffy meta
classes, taken from the world of aspect-oriented programming. As long as
you write Python, it's ok; you don't have to use that. But surely there
are some people who have used it in their programs in the past and
there's a certain probability that this happened in one of the programs
you have to read. Aspect-oriented programming mixes very badly with the
traditional OO-style of programs. It only makes sense if a program was
designed aspect-orientedly from the ground up. That, of course, is
unprecedented in Python because those meta classes are so wicked that no
brain of the average programmer is capable of grokking them.
In my estimation, Python has tried to become too smart over the past
years. There's just too much stuff that was thrown into the language
in a random fashion because it looked appealing on first sight. Those
things then remained incomplete for a long time (think of the crippled
lambda operator that was only able to handle a single expression quite
unlike real closures known from Perl and Ruby).
Tassilo
--
$_=q#",}])!JAPH!qq(tsuJ[{@"tnirp}3..0}_$;//::niam/s~=)]3[))_$-3(rellac(=_$({
pam{rekcahbus})(rekcah{lrePbus})(lreP{rehtonabus})!JAPH!qq(rehtona{tsuJbus#;
$_=reverse,s+(?<=sub).+q#q!'"qq.\t$&."'!#+sexisexiixesixeseg;y~\n~~dddd;eval
------------------------------
Date: Fri, 3 Dec 2004 13:32:20 +0900
From: Vito Corleone <corleone@godfather.com>
Subject: Re: Reference to hash and array
Message-Id: <20041203133220.44ab1f64.corleone@godfather.com>
Ok, I got it now. Thanks Karl :)
On Thu, 2 Dec 2004 16:44:11 +0000 (UTC)
KKramsch <karlUNDERSCOREkramsch@yahooPERIODcom.invalid> wrote:
> In <20041202223711.70c830f3.corleone@godfather.com> Vito Corleone <corleone@godfather.com> writes:
>
> >Hi,
> >I downloaded a module that need me to input the value in very confusing
> >way. For example:
> >$m = Module::->new(
> > { 'servers' => [ "192.168.1.0:5500", "192.168.1.1:5500" ],
> > 'debug' => 0 } );
>
> >You put the list of your servers IP and port number into servers. I put
> >my servers list in config file. It looks like this:
> >use constant SERVERS => '192.168.1.0:5500 192.168.1.1:5500';
>
> >And then when I load the module, I do:
> >my @servers = split(" ", SERVERS);
> >$m = Module::->new(
> > { 'servers' => \@servers,
> > 'debug' => 0 } );
>
> >So far so good. But you can also load the module this way.
> >$m = Module::->new(
> > { 'servers' => [ "192.168.1.0:5500", ["192.168.1.1:5500", 3] ],
> > 'debug' => 0 } );
>
> >Besides IP and port number, it also takes the value of the server (ie:
> >3). I want to make my config file looks like:
> >use constant SERVERS => '192.168.1.0:5500 192.168.1.1:5500,3';
>
> >But I don't know how can I pass these values to the module. Or is there
> >any better way to keep these values in config file? Please help, and
> >thanks in advance.
>
> What Anno posted is right, I'm sure, but the code below may be
> easier to follow.
>
> # untested
> my @servers;
> for my $info (split ' ', SERVERS) {
> # $info is either of the form ip:port" or "ip:port,num"
> my ($ip_port, $num) = split /,/, $info;
> if ($num) {
> # $info is of the form "ip:port,num"
> push @servers, [$ip_port, $num];
> }
> else {
> # info is of the form "ip:port"
> push @servers, $info;
> }
> }
>
> my $m = Module::->new( { 'servers' => \@servers,
> 'debug' => 0 } );
>
> __END__
>
> Makes sense?
>
> Karl
>
> --
> Sent from a spam-bucket account; I check it once in a blue moon. If
> you still want to e-mail me, cut out the extension from my address,
> and make the obvious substitutions on what's left.
------------------------------
Date: Thu, 2 Dec 2004 23:39:39 -0600
From: Tad McClellan <tadmc@augustmail.com>
Subject: Re: testing for existence of an inline file with Inline::Files
Message-Id: <slrncqvv0r.cmo.tadmc@magna.augustmail.com>
Sven Wolf <swolf2@yahoo.com> wrote:
> Hello,
>
> I'm using Inline::Files, which allows me to put data after __FOO__ in
> a file and then to read it with "while (<FOO>) {...}" or @lines =
><FOO>;
> I get a read-from-unopened-filehandle error if there is no section
> __MYCANDIDATE__ in the script.
>
> Can someone suggest a test to apply before attempting to read?
The docs say that a package variable named $MYCANDIDATE will
exist if there is such a section. You can just look in the
symbol table to see if one by that name is there or not.
This seems to work for me:
die 'no such section' unless exists $main::{MYCANDIDATE};
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
Date: Thu, 02 Dec 2004 20:11:49 -0600
From: brian d foy <comdog@panix.com>
Subject: The Perl Review, Winter 2004
Message-Id: <021220042011493343%comdog@panix.com>
The second print issue of The Perl Review is now on the presses
and will be mailed next week, so you have time to get your name
on the subscriber list. TPR is the only print magazine devoted
to Perl.
http://www.theperlreview.com/
In this issue ( 1.1, Winter 2004 )
* Down Translating XML -- Alberto Manuel Simões
* Module::Release and Beyond -- brian d foy
* Functional Perl Programming -- Frank Antonsen
* Faking Stored Procedures -- Zach Thompson
plus Perl News, Perl Mongers and Perl Foundation reports, book
reviews, and short notes.
The first print issue ( 1.0 ) is still available to subscribers online
as a PDF file, and some back issues are available.
* Test Driven Development -- Denis Kosykh
* Just do{} it -- brian d foy
* Extending XML::XPath -- Michel Rodriguez
* Test::More in 20 Seconds -- brian d foy
* Magick Tile Puzzles -- Grant McLean
Before that, The Perl Review was a digital only version with
eight issues which are still available for free download as
PDF files.
http://www.theperlreview.com/Issues/
RSS Feeds are available too.
Subscriber only (current) issues
http://www.theperlreview.com/RSS/tpr-subscribers.rdf
Free Issues and articles
http://www.theperlreview.com/RSS/tpr-free.rdf
The Perl Review news
http://www.livejournal.com/users/perl_review/data/rss
The Perl Review public discussion
http://www.livejournal.com/community/the_perl_review/data/rss
Want to write for TPR? Send us a note, or submit an idea online
http://www.theperlreview.com/Authors/submit.html
Prices: $16 in the US, $30 outside the US. If we can get enough
subscribers in the European Union, we'll start printing there too and
lower the cost. We're working on an online only version as well.
TPR accepts MasterCard, Visa, American Express, PayPal, Amazon.com
Honors System, and check or money order in US dollars. Sorry, but we
can only accept advance payment since we're too small to do handle
individual billing.
Samples to Perl user groups, Perl instructors, and other worthy causes
are available.
--
brian d foy, comdog@panix.com
Subscribe to The Perl Review: http://www.theperlreview.com
------------------------------
Date: Fri, 03 Dec 2004 14:30:53 +1100
From: Iain Chalmers <bigiain@mightymedia.com.au>
Subject: Re: The Perl Review, Winter 2004
Message-Id: <bigiain-BBAEEC.14305303122004@individual.net>
In article <021220042011493343%comdog@panix.com>,
brian d foy <comdog@panix.com> wrote:
> Prices: $16 in the US, $30 outside the US. If we can get enough
> subscribers in the European Union, we'll start printing there too and
> lower the cost. We're working on an online only version as well.
I'd be interested in an online version, I'd almost even be happy to pay
the $16 US price for access to the PDF downloads...
big (not interested in paying $14 to fly dead trees around the planet)
--
"I say we take off and nuke the entire site from orbit.
That's the only way to be sure." - Ellen Ripley
------------------------------
Date: Fri, 03 Dec 2004 01:49:10 -0600
From: brian d foy <comdog@panix.com>
Subject: Re: The Perl Review, Winter 2004
Message-Id: <031220040149107708%comdog@panix.com>
In article <bigiain-BBAEEC.14305303122004@individual.net>, Iain
Chalmers <bigiain@mightymedia.com.au> wrote:
> In article <021220042011493343%comdog@panix.com>,
> brian d foy <comdog@panix.com> wrote:
> > Prices: $16 in the US, $30 outside the US. If we can get enough
> > subscribers in the European Union, we'll start printing there too and
> > lower the cost. We're working on an online only version as well.
> I'd be interested in an online version, I'd almost even be happy to pay
> the $16 US price for access to the PDF downloads...
> big (not interested in paying $14 to fly dead trees around the planet)
I'm working on an online only version, and now that the latest issue
is finished I have time to do other things. :)
--
brian d foy, comdog@panix.com
Subscribe to The Perl Review: http://www.theperlreview.com
------------------------------
Date: Fri, 3 Dec 2004 18:52:16 +1100
From: "David" <gyruss@hushmail.com>
Subject: vbscript or perl
Message-Id: <41b01b30$1_1@news.iprimus.com.au>
Dear all,
I have to port a moderately complicated unix shell script written for
Solaris to Windows. I've never done Windows scripting before. Should I
(a) learn VBScript and implement it in that;
(b) install Active Perl on the target Windows box and rewrite the script in
perl (which I am familiar with).
The script in question most does database stuff e.g. calls stored procs,
parses text files then loads new records with bcp.
Cheers,
David
------------------------------
Date: Fri, 03 Dec 2004 02:14:20 -0600
From: Alan Mead <amead@comcast.net>
Subject: Re: vbscript or perl
Message-Id: <pan.2004.12.03.08.14.18.915022@comcast.net>
On Fri, 03 Dec 2004 18:52:16 +1100, David wrote:
> I have to port a moderately complicated unix shell script written for
> Solaris to Windows. I've never done Windows scripting before. Should I
>
> (a) learn VBScript and implement it in that;
> (b) install Active Perl on the target Windows box and rewrite the script in
> perl (which I am familiar with).
>
> The script in question most does database stuff e.g. calls stored procs,
> parses text files then loads new records with bcp.
David,
I think clearly vbscript would be the way to go. Microsoft has spent a
lot of money on research that shows that all their products beat
everything else. Besides, who's ever heard of someone using Perl for
goofy stuff like processing text or accessing databases!? I don't think
it does that...
It's really a no-brainer. I'm kind of embarassed that you asked at all.
Have fun learning vbscript.
-Alan
------------------------------
Date: 3 Dec 2004 09:27:37 GMT
From: Philipp Pagel <pDOTpagel@gsf.de>
Subject: Re: vbscript or perl
Message-Id: <31aps7F37qnrlU1@individual.net>
David <gyruss@hushmail.com> wrote:
> I have to port a moderately complicated unix shell script written for
> Solaris to Windows. I've never done Windows scripting before. Should I
> (a) learn VBScript and implement it in that;
> (b) install Active Perl on the target Windows box and rewrite the script in
> perl (which I am familiar with).
How about
(c) install cygwin to have bash/tcsh or whatever shell the original
scripts were using and don't port to a new language at all.
cu
Philipp
--
Dr. Philipp Pagel Tel. +49-89-3187-3675
Institute for Bioinformatics / MIPS Fax. +49-89-3187-3585
GSF - German National Research Center for Environment and Health
http://mips.gsf.de/staff/pagel
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
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Subject: Digest Administrivia (Last modified: 6 Apr 01)
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------------------------------
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