[25019] in Perl-Users-Digest
Perl-Users Digest, Issue: 7269 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Oct 19 06:07:18 2004
Date: Tue, 19 Oct 2004 03:05:05 -0700 (PDT)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Tue, 19 Oct 2004 Volume: 10 Number: 7269
Today's topics:
Re: Calling a perl script from an html doc <MrReallyVeryNice.REMOVE.NO.SPAM@Yahoo.REMOVE.NO.SPAM.com>
Re: Calling a perl script from an html doc <ebohlman@omsdev.com>
Re: Calling a perl script from an html doc lesley_b_linux@yahoo.co.yuk
Re: Editable webpage code - security loopholes? <tadmc@augustmail.com>
Re: How do I print http 404 not found header? lesley_b_linux@yahoo.co.uk
Re: How do I print http 404 not found header? <flavell@ph.gla.ac.uk>
Re: Lowest array value given index <ebohlman@omsdev.com>
Re: Lowest array value given index <dha@panix.com>
Re: Lowest array value given index <ebohlman@omsdev.com>
Re: Lowest array value given index <abigail@abigail.nl>
Re: Lowest array value given index (Anno Siegel)
Re: Lowest array value given index <dha@panix.com>
Re: options to shrink-wrap a perl script <tadmc@augustmail.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Re: References to an array in a foreach <ebohlman@omsdev.com>
Re: regex to clean path (Anno Siegel)
Regular Expression for HTML Tags and Special Characters (Marc Bogaard)
Re: Regular Expression for HTML Tags and Special Charac <josef.moellers@fujitsu-siemens.com>
Re: Top posting <flavell@ph.gla.ac.uk>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Mon, 18 Oct 2004 21:12:44 -0700
From: MrReallyVeryNice <MrReallyVeryNice.REMOVE.NO.SPAM@Yahoo.REMOVE.NO.SPAM.com>
Subject: Re: Calling a perl script from an html doc
Message-Id: <u7WdnR5J-4SSCencRVn-hg@comcast.com>
Spin wrote:
> Sorry, my fault for not being explicit enough.
>
> There is no web server. There is a file server (samba) on which the html doc
> is located. The file server has perl installed, but no web server. And
> installing a web server is not an option.
Guessing that you cannot install a web server on the samba server
because you are not authorized to do so, you might consider installing
the web server on your own personal machine running W2K. Again, that
would assume that:
- this installation is possible ( you have administrator access to
your own machine, right?, you have enough disk space and CPU power, right?)
- this installation is authorized (your IT department or other
Management would not get you in trouble if they found out that you have
a web server).
If the above scenario is a possibility, then you could have the 'HTML
templates/docs' saved on the samba server but the perl script processing
done by your web server CGI.
This scenario would only be interesting if you are dealing with a small
group of users because you might run into a load/performance issues.
Without information about your configuration, about what
my_perl_script_gets_my_dynamic_image.pl is supposed to do, it is
difficult to say what other issues you would run into.
MrReallyVeryNice
>
> Caleb
>
>
------------------------------
Date: 19 Oct 2004 05:46:41 GMT
From: Eric Bohlman <ebohlman@omsdev.com>
Subject: Re: Calling a perl script from an html doc
Message-Id: <Xns95878E2A109ebohlmanomsdevcom@130.133.1.4>
"Spin" <spam@spamhotmail.com> wrote in
news:10n81aujp20bq23@corp.supernews.com:
> There is no web server. There is a file server (samba) on which the
> html doc is located. The file server has perl installed, but no web
> server. And installing a web server is not an option.
Why, specifically, is it not an option? Are you and whoever is in charge
of the server both aware that it's possible (and easy) to configure a Web
server so that it will respond *only* to requests that originate on your
LAN, or even specific segments of your LAN, *without* making any data at
all available over the Internet?
I have an Apache server set up on my machine. No process running on any
other machine is even capable of telling that it's there.
------------------------------
Date: 19 Oct 2004 09:08:48 +0100
From: lesley_b_linux@yahoo.co.yuk
Subject: Re: Calling a perl script from an html doc
Message-Id: <m3d5zft9in.fsf@helmholtz.local>
"Jürgen Exner" <jurgenex@hotmail.com> writes:
> lesley_b_linux@yahoo.co.yuk wrote:
> > While we're on the subject of CGI, I've always understood it to stand
> > for Common Gateway Interface. From my experience the end result is
> > that some perl scripts are executed.
>
> That is a very limited point of view. Or a very limited experience.
As I said, from my experience.
Having read http://hoohoo.ncsa.uiuc.edu/cgi/overview.html I have improved
my knowledge.
Having shared the URL, I have given others the opportunity to understand more
about CGI and perhaps helped improve some people's expectations of what CGI.pm
can and cannot do.
>
> > Has there ever been any other
> > language used with CGI or was CGI specifically designed to work with
> > Perl and nothing else?
>
> OHMYGOD. You are kidding, aren't you?
Now, is that really the best you can offer this newsgroup?
Lesley
------------------------------
Date: Tue, 19 Oct 2004 00:20:46 -0500
From: Tad McClellan <tadmc@augustmail.com>
Subject: Re: Editable webpage code - security loopholes?
Message-Id: <slrncn991e.3io.tadmc@magna.augustmail.com>
Duke of Hazard <squash@peoriadesignweb.com> wrote:
> It works, but what security checks do I need to perform on it? I
> realize I need to sanitize the password field, how about the textarea
> field?
If you need to "sanitize" them when using Perl, then you would
need to sanitize them when using Visual Basic or C or Java.
ie. That question is not a Perl question.
Please ask web questions in a newsgroup about the web.
> open(F, "$file_path") ;
You should always, yes *always*, check the return value from open:
open(F, $file_path) or die "could not open '$file_path' $!";
See also:
perldoc -q vars
What's wrong with always quoting "$vars"?
Then don't use useless uses of quotes anymore.
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
Date: 19 Oct 2004 09:02:53 +0100
From: lesley_b_linux@yahoo.co.uk
Subject: Re: How do I print http 404 not found header?
Message-Id: <m3hdort9si.fsf@helmholtz.local>
"Alan J. Flavell" <flavell@ph.gla.ac.uk> writes:
> On Mon, 18 Oct 2004 lesley_b_linux@yahoo.co.yuk wrote:
>
> > In a totally OT way :
> >
> > From RFC2616
>
> RFC2616 is *not* a CGI specification.
Correct, 10 out 10, go to the top of the class :)
It does however happen to specify HTTP responses in Section 6
However if you want a CGI specification the nearest I can offer was a URL
posted in another thread --> http://hoohoo.ncsa.uiuc.edu/cgi/overview.html
HTH
Lesley
------------------------------
Date: Tue, 19 Oct 2004 10:59:28 +0100
From: "Alan J. Flavell" <flavell@ph.gla.ac.uk>
Subject: Re: How do I print http 404 not found header?
Message-Id: <Pine.LNX.4.61.0410191047140.556@ppepc56.ph.gla.ac.uk>
On Tue, 19 Oct 2004 lesley_b_linux@yahoo.co.uk wrote:
> "Alan J. Flavell" <flavell@ph.gla.ac.uk> writes:
>
> > On Mon, 18 Oct 2004 lesley_b_linux@yahoo.co.yuk wrote:
> >
> > > From RFC2616
> >
> > RFC2616 is *not* a CGI specification.
>
> Correct, 10 out 10, go to the top of the class :)
-Ž
> It does however happen to specify HTTP responses in Section 6
That's not surprising, since it's the HTTP/1.1 specification.
As the relevant Perl FAQ says, at e.g
http://www.perldoc.com/perl5.8.4/pod/perlfaq9.html#What-is-the-correct-form-of-response-from-a-CGI-script-
The similarity between CGI response headers (defined in the CGI
specification) and HTTP response headers (defined in the HTTP
specification, RFC2616) is intentional, but can sometimes be
confusing.
> However if you want a CGI specification the nearest I can offer was
> a URL posted in another thread -->
> http://hoohoo.ncsa.uiuc.edu/cgi/overview.html
Actually, I prefer the one referenced in the Perl FAQ part 9:
Current best-practice RFC draft at: http://CGI-Spec.Golux.Com/
although it never does seem to have quite made it to the
originally-mooted RFC status. Maybe the IETF don't really consider
the CGI interface to be in their parish, but Ken did an excellent
piece of work in collating a best-practice specification, and it seems
to me that it's the best that we've got (the NCSA spec is rather
informal, and leaves many questions unanswered).
> HTH
U2. :-}
------------------------------
Date: 19 Oct 2004 04:43:03 GMT
From: Eric Bohlman <ebohlman@omsdev.com>
Subject: Re: Lowest array value given index
Message-Id: <Xns9586F23CDE6DEebohlmanomsdevcom@130.133.1.4>
"David H. Adler" <dha@panix.com> wrote in
news:slrncn0b8v.t1k.dha@panix2.panix.com:
> Something along the lines of
>
> $result = find_lowest_element(@array[$index..$#array])
>
> should solve part of your problem.
>
> [benchmarks]
>
> Holy moley!
>
> Benchmark: timing 500000 iterations of slice, splice...
> slice: 351 wallclock secs (183.32 usr + 1.25 sys = 184.57 CPU)
> @ 2709.00/s (n=500000)
>
> splice: 2 wallclock secs ( 0.37 usr + 0.02 sys = 0.39 CPU) @
> 1282051.28/s (n=500000)
>
> Ok, *don't* do that.
>
> $result = find_lowest_element(splice @array, $index);
Er, I think the reason it's running so fast is that it isn't doing what it
ought to. That's the equivalent of:
@array=@array[0..$index-1];
$result=find_lowest_element(@array);
So you're looking only at elements *before* $index, contrary to the OP's
spec, *and* you're truncating @array to the number of elements given by the
smallest value of $index, which was probably one of the first ones used (if
your test code was refreshing @array on each iteration, then ignore my
second clause).
------------------------------
Date: Tue, 19 Oct 2004 05:20:32 +0000 (UTC)
From: "David H. Adler" <dha@panix.com>
Subject: Re: Lowest array value given index
Message-Id: <slrncn9910.ice.dha@panix2.panix.com>
On 2004-10-19, Eric Bohlman <ebohlman@omsdev.com> wrote:
> "David H. Adler" <dha@panix.com> wrote in
> news:slrncn0b8v.t1k.dha@panix2.panix.com:
>
>> Something along the lines of
>>
>> $result = find_lowest_element(@array[$index..$#array])
>>
>> should solve part of your problem.
>>
>> [benchmarks]
>>
>> Holy moley!
>>
>> Benchmark: timing 500000 iterations of slice, splice...
>> slice: 351 wallclock secs (183.32 usr + 1.25 sys = 184.57 CPU)
>> @ 2709.00/s (n=500000)
>>
>> splice: 2 wallclock secs ( 0.37 usr + 0.02 sys = 0.39 CPU) @
>> 1282051.28/s (n=500000)
>>
>> Ok, *don't* do that.
>>
>> $result = find_lowest_element(splice @array, $index);
>
> Er, I think the reason it's running so fast is that it isn't doing what it
> ought to. That's the equivalent of:
>
> @array=@array[0..$index-1];
> $result=find_lowest_element(@array);
>
> So you're looking only at elements *before* $index, contrary to the OP's
> spec, *and* you're truncating @array to the number of elements given by the
> smallest value of $index, which was probably one of the first ones used (if
> your test code was refreshing @array on each iteration, then ignore my
> second clause).
Hm. Perhaps I'm confused, but how do you get that?
My code for those benchmarks was:
my @init = (1..1000);
timethese( shift || 10000,
{ slice => sub {my @array = @init[30..1000];},
splice => sub {my @array = splice @init, 30;}
});
So I'm not sure how you're getting a range of [0..$index-1];
In any case, I just noticed a slight oddity. if I change the slice code
to
sub {my @array = @init[30..-1];}
we get this benchmark:
Benchmark: timing 1000000 iterations of slice, splice...
slice: 1 wallclock secs ( 0.64 usr + 0.03 sys = 0.67 CPU)
@ 1492537.31/s (n=1000000)
splice: 0 wallclock secs ( 0.70 usr + 0.01 sys = 0.71 CPU)
@ 1408450.70/s (n=1000000)
Is it me or is that just odd?
dha
--
David H. Adler - <dha@panix.com> - http://www.panix.com/~dha/
"Perl Porters, Inc. today announced the release of version .006 of
their popular Perl5 compiler suite, codenamed `Rabid Rat'."
- Nathan Torkington on p5p (this was a *joke*)
------------------------------
Date: 19 Oct 2004 06:07:16 GMT
From: Eric Bohlman <ebohlman@omsdev.com>
Subject: Re: Lowest array value given index
Message-Id: <Xns9587C5FB918Cebohlmanomsdevcom@130.133.1.4>
"David H. Adler" <dha@panix.com> wrote in
news:slrncn9910.ice.dha@panix2.panix.com:
> On 2004-10-19, Eric Bohlman <ebohlman@omsdev.com> wrote:
>> So you're looking only at elements *before* $index, contrary to the
>> OP's spec, *and* you're truncating @array to the number of elements
>> given by the smallest value of $index, which was probably one of the
>> first ones used (if your test code was refreshing @array on each
>> iteration, then ignore my second clause).
>
> Hm. Perhaps I'm confused, but how do you get that?
>
> My code for those benchmarks was:
>
> my @init = (1..1000);
>
> timethese( shift || 10000,
> { slice => sub {my @array = @init[30..1000];},
> splice => sub {my @array = splice @init, 30;}
> });
>
> So I'm not sure how you're getting a range of [0..$index-1];
I had forgotten that splice() returns the *removed* elements rather than
the remaining ones (actually *reading*, rather than *skimming*, the docs
for splice() cleared that up). However, there's still a problem. After
the first iteration, splice() will have truncated @init to 30 elements and
will return an empty list on subsequent iterations.
------------------------------
Date: 19 Oct 2004 07:28:47 GMT
From: Abigail <abigail@abigail.nl>
Subject: Re: Lowest array value given index
Message-Id: <slrncn9ghf.img.abigail@alexandra.abigail.nl>
David H. Adler (dha@panix.com) wrote on MMMMLXVII September MCMXCIII in
<URL:news:slrncn9910.ice.dha@panix2.panix.com>:
##
## My code for those benchmarks was:
##
## my @init = (1..1000);
##
## timethese( shift || 10000,
## { slice => sub {my @array = @init[30..1000];},
## splice => sub {my @array = splice @init, 30;}
## });
Ah, I see you missed my talk at YAPC. ;-) After a few iterations,
you have spliced all elements from @init, making @init an empty
array. So, your benchmark proves that splicing from an empty
array is a lot faster than copying 970 elements.
Which isn't a big surprise to me.
##
## So I'm not sure how you're getting a range of [0..$index-1];
##
## In any case, I just noticed a slight oddity. if I change the slice code
## to
##
## sub {my @array = @init[30..-1];}
That doesn't do what you want either. 30 .. -1 contains all the integers
that are at least 30, and at most -1. Which is none. So all
my @array = @init [30 .. -1];
is doing is creating an empty array.
## we get this benchmark:
##
## Benchmark: timing 1000000 iterations of slice, splice...
## slice: 1 wallclock secs ( 0.64 usr + 0.03 sys = 0.67 CPU)
## @ 1492537.31/s (n=1000000)
## splice: 0 wallclock secs ( 0.70 usr + 0.01 sys = 0.71 CPU)
## @ 1408450.70/s (n=1000000)
##
## Is it me or is that just odd?
It's you ;-)
Abigail
--
# Perl 5.6.0 broke this.
%0=map{reverse+chop,$_}ABC,ACB,BAC,BCA,CAB,CBA;$_=shift().AC;1while+s/(\d+)((.)
(.))/($0=$1-1)?"$0$3$0{$2}1$2$0$0{$2}$4":"$3 => $4\n"/xeg;print#Towers of Hanoi
------------------------------
Date: 19 Oct 2004 07:33:43 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: Lowest array value given index
Message-Id: <cl2g0n$rhm$1@mamenchi.zrz.TU-Berlin.DE>
David H. Adler <dha@panix.com> wrote in comp.lang.perl.misc:
> On 2004-10-19, Eric Bohlman <ebohlman@omsdev.com> wrote:
> > "David H. Adler" <dha@panix.com> wrote in
> > news:slrncn0b8v.t1k.dha@panix2.panix.com:
> >
> >> Something along the lines of
> >>
> >> $result = find_lowest_element(@array[$index..$#array])
> >>
> >> should solve part of your problem.
> >>
> >> [benchmarks]
> >>
> >> Holy moley!
> >>
> >> Benchmark: timing 500000 iterations of slice, splice...
> >> slice: 351 wallclock secs (183.32 usr + 1.25 sys = 184.57 CPU)
> >> @ 2709.00/s (n=500000)
> >>
> >> splice: 2 wallclock secs ( 0.37 usr + 0.02 sys = 0.39 CPU) @
> >> 1282051.28/s (n=500000)
> >>
> >> Ok, *don't* do that.
> >>
> >> $result = find_lowest_element(splice @array, $index);
> >
> > Er, I think the reason it's running so fast is that it isn't doing what it
> > ought to. That's the equivalent of:
> >
> > @array=@array[0..$index-1];
> > $result=find_lowest_element(@array);
> >
> > So you're looking only at elements *before* $index, contrary to the OP's
> > spec, *and* you're truncating @array to the number of elements given by the
> > smallest value of $index, which was probably one of the first ones used (if
> > your test code was refreshing @array on each iteration, then ignore my
> > second clause).
>
> Hm. Perhaps I'm confused, but how do you get that?
>
> My code for those benchmarks was:
>
> my @init = (1..1000);
>
> timethese( shift || 10000,
> { slice => sub {my @array = @init[30..1000];},
> splice => sub {my @array = splice @init, 30;}
> });
>
> So I'm not sure how you're getting a range of [0..$index-1];
No, but splice will consume @init after a few rounds and do nothing
after that. Depending on which will run first, slice will see an
empty array or not.
> In any case, I just noticed a slight oddity. if I change the slice code
> to
>
> sub {my @array = @init[30..-1];}
Well, that makes sure that slice doesn't do nothing in either case.
I think you want "@init[30 .. $#init]".
For a real benchmark one would have to reset @init before each run
(Results slightly edited):
my @supply = (1..1000);
timethese( shift || -3, {
slice => sub {my @init = @supply; my @array = @init[30..-1];},
splice => sub {my @init = @supply; my @array = splice @init, 30;},
null => sub { my @init = @supply },
},
);
Benchmark: running null, slice, splice for at least 3 CPU seconds...
null: 3 wallclock secs ( 3.19 CPU) @ 181.82/s (n=580)
slice: 3 wallclock secs ( 3.20 CPU) @ 177.81/s (n=569)
splice: 4 wallclock secs ( 3.17 CPU) @ 85.80/s (n=272)
That is as expected, but the results for "null" show that most of
the time in slice is spent in the array assignment.
Anno
------------------------------
Date: Tue, 19 Oct 2004 07:50:21 +0000 (UTC)
From: "David H. Adler" <dha@panix.com>
Subject: Re: Lowest array value given index
Message-Id: <slrncn9hpt.51g.dha@panix2.panix.com>
On 2004-10-19, Abigail <abigail@abigail.nl> wrote:
> David H. Adler (dha@panix.com) wrote on MMMMLXVII September MCMXCIII in
[snip lots of benchmarking in odd directions]
> ## Is it me or is that just odd?
>
>
> It's you ;-)
Yes. Yes it is. Time for sleep I think.
dha
--
David H. Adler - <dha@panix.com> - http://www.panix.com/~dha/
I'd redesign my program to something less absurd.
- Abigail, in comp.lang.perl.misc
------------------------------
Date: Tue, 19 Oct 2004 00:14:00 -0500
From: Tad McClellan <tadmc@augustmail.com>
Subject: Re: options to shrink-wrap a perl script
Message-Id: <slrncn98ko.3io.tadmc@magna.augustmail.com>
dan baker <botfood@yahoo.com> wrote:
> wow, what a passive-aggressive bunch! excuse me for not being a mind
> reader.
Excuse me for never reading any more of your posts.
*plonk*
> doesn't occur to YOU that something like
typing "perl PAR" into the little box at www.google.com finds it
just fine.
Do you want us to hold your hand?
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
Date: 19 Oct 2004 07:22:20 GMT
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.5 $)
Message-Id: <4174c0ab$0$6877$8b463f8a@news.nationwide.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
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Social faux pas to avoid
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Be extra cautious when you get upset
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- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.5 $)
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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: 19 Oct 2004 04:29:20 GMT
From: Eric Bohlman <ebohlman@omsdev.com>
Subject: Re: References to an array in a foreach
Message-Id: <Xns9586EFE9CC8B6ebohlmanomsdevcom@130.133.1.4>
"David H. Adler" <dha@panix.com> wrote in
news:slrncmu6j3.206.dha@panix2.panix.com:
> On 2004-10-14, A. Sinan Unur <usa1@llenroc.ude.invalid> wrote:
>>
>> What you really want to use is a hash for animals
>
> Really, this sounds like something the SPCA might come after you for...
>:-)
I could see them objecting to a hash *of* animals, but what would worry
them about a hash *for* animals? :)
------------------------------
Date: 19 Oct 2004 09:46:44 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: regex to clean path
Message-Id: <cl2nq4$2pq$1@mamenchi.zrz.TU-Berlin.DE>
Jon Ericson <Jon.Ericson@jpl.nasa.gov> wrote in comp.lang.perl.misc:
> "Yuri Shtil" <yshtil@synopsys.com> writes:
>
> > I need to clean the PATH variable from redundant entries:
> >
> > a:b:c:c:c:s:a
> > should become a:b:v:s.
>
> I think you meant a:b:c:s.
>
> > I have written a few line script that does it using hash.
> >
> > Does anybody know an elegant oneliner using regex?
>
> $ perl -e '%h = map {$_ => 1} split(/:/, "a:b:c:c:c:s:a");\
> print join(":", sort keys %h), "\n"'
>
> Finding the regex is left as an exercise for the reader. ;-) Sorting
> alphabeticaly might not be what you want.
Indeed. The sequence of path elements is significant, so they should
appear in the cleaned-up path in the same order they had in the original.
Anno
------------------------------
Date: 18 Oct 2004 23:51:11 -0700
From: marc.bogaard@gmx.de (Marc Bogaard)
Subject: Regular Expression for HTML Tags and Special Characters
Message-Id: <d7f1659a.0410182251.63942d4d@posting.google.com>
Hello together!
How can I allowed some HTML-Tags like <BR>, <B>, <P> but
filter out <, >, when they stand alone?
Must be something like: "^[A-Za-Z0-9\>\<]+$"
for the < and >, but where do i have to put in my tags?
thank you in advance
marc van den Bogaard
------------------------------
Date: Tue, 19 Oct 2004 10:14:35 +0200
From: Josef Moellers <josef.moellers@fujitsu-siemens.com>
Subject: Re: Regular Expression for HTML Tags and Special Characters
Message-Id: <cl2i8e$lsj$1@nntp.fujitsu-siemens.com>
Marc Bogaard wrote:
> Hello together!
>=20
> How can I allowed some HTML-Tags like <BR>, <B>, <P> but
> filter out <, >, when they stand alone?=20
>=20
> Must be something like: "^[A-Za-Z0-9\>\<]+$"
> for the < and >, but where do i have to put in my tags?
how about "<[a-zA-Z0-9]{1,2}>"?
--=20
Josef M=F6llers (Pinguinpfleger bei FSC)
If failure had no penalty success would not be a prize
-- T. Pratchett
------------------------------
Date: Tue, 19 Oct 2004 09:07:58 +0100
From: "Alan J. Flavell" <flavell@ph.gla.ac.uk>
Subject: Re: Top posting
Message-Id: <Pine.LNX.4.61.0410190904410.509@ppepc56.ph.gla.ac.uk>
On Mon, 18 Oct 2004, Jon Ericson wrote:
> "bxb7668" <bxb7668@somewhere.nocom> writes:
>
> > Most of the Microsoft newsgroups that I trawl have about a 50-50
> > split between top and bottom posters. An example is
> > microsoft.public.windowsxp.basics.
>
> Somehow I don't think the Microsoft groups are the best examples. ;-)
I find them an excellent practical demonstration of why usenet has a
long-standing convention for how to quote from previous posts, and of
what goes wrong when this convention is flouted.
But not, of course, as an example to be followed!
------------------------------
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 V10 Issue 7269
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