[23016] in Perl-Users-Digest
Perl-Users Digest, Issue: 5236 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Jul 18 06:05:49 2003
Date: Fri, 18 Jul 2003 03:05:06 -0700 (PDT)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Fri, 18 Jul 2003 Volume: 10 Number: 5236
Today's topics:
Re: Behind the scene <mpapec@yahoo.com>
Converting Perl5 into Perl4 (kielhd)
Re: Converting Perl5 into Perl4 <uri@stemsystems.com>
display image during runtime (Alythh)
Re: How to match all characters in a Character Class <foo@bar.com>
Re: HTML REGEX <bigj@kamelfreund.de>
Re: macros in perl <tzz@lifelogs.com>
Re: perlstyles <scare.crow@oz.land>
Re: perlstyles (Jay Tilton)
Re: perlstyles <mpapec@yahoo.com>
Re: perlstyles <mpapec@yahoo.com>
Re: perlstyles <scare.crow@oz.land>
Re: perlstyles <bigj@kamelfreund.de>
Re: perlstyles <bigj@kamelfreund.de>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Re: Removing Perl comments and strings using regexps <tassilo.parseval@rwth-aachen.de>
Writing Javascript and some Style into .CGI? (Bill S.)
Re: Writing Javascript and some Style into .CGI? <bigj@kamelfreund.de>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 18 Jul 2003 11:12:59 +0200
From: Matija Papec <mpapec@yahoo.com>
Subject: Re: Behind the scene
Message-Id: <7cefhv8873dao3sa18h9tmo6pc2bil3pqn@4ax.com>
X-Ftn-To: Uri Guttman
Uri Guttman <uri@stemsystems.com> wrote:
> >> certainly could have landed a full-time job 20 months ago if I'd
> >> been willing to forget about Perl 6.
>
> MP> huh?
>
>larry has been working on the perl6 apocalypses and design for much of
>this period. he has been funded partly by the perl foundation but has
>not had major income from them. and he has 2 kids in college, a
>mortgage, etc. so he has sacrificed a lot. his comment above means he
>could have had a decent paying job but he turned it down instead to work
>on perl6.
<phew>, I thought at the moment that somebody offered him a money to abandon
his further Perl work. ;)
>so the way you can help is to donate money to the perl foundation and
>help larry pay for his mortgage. :)
Is there possibility to purchase perl cd or something that would also help?
--
Matija
------------------------------
Date: 17 Jul 2003 22:45:23 -0700
From: kielhd@freenet.de (kielhd)
Subject: Converting Perl5 into Perl4
Message-Id: <10a4173d.0307172145.565b55c2@posting.google.com>
Hi NG,
Sometimes I need to convert a script written in Perl5 into Perl4.
As this is a boring and very time-consuming task, I am looking for a
way to automate this.
Are there tools available for this job?
Thanks in advance
Henning
------------------------------
Date: Fri, 18 Jul 2003 05:55:16 GMT
From: Uri Guttman <uri@stemsystems.com>
Subject: Re: Converting Perl5 into Perl4
Message-Id: <x7r84ofkfv.fsf@mail.sysarch.com>
>>>>> "k" == kielhd <kielhd@freenet.de> writes:
k> Sometimes I need to convert a script written in Perl5 into Perl4.
k> As this is a boring and very time-consuming task, I am looking for a
k> way to automate this.
k> Are there tools available for this job?
hahahahahahha!!
sorry, but that is such a bad idea in so many ways. i hate to even know
why this has to be done. in fact it can't (easily) be done if the perl5
code has even one reference.
uri
--
Uri Guttman ------ uri@stemsystems.com -------- http://www.stemsystems.com
--Perl Consulting, Stem Development, Systems Architecture, Design and Coding-
Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org
------------------------------
Date: 18 Jul 2003 00:53:26 -0700
From: alythh@netscape.net (Alythh)
Subject: display image during runtime
Message-Id: <6a25ba72.0307172353.13e89292@posting.google.com>
for the first time I'm trying to add graphics to a Perl program, and
I'm thinking using the GD module.
I see how easily you can create images/graphs... but, there is an easy
way to open a window to display the image - during prog execution -
and to send sometime a command to it to update the image, when
necessary?
P.S. probably the question is more general than a GD question, it
regards how to easily display an image at runtime ...
Thanks for any info
Alessandro Magni
------------------------------
Date: Fri, 18 Jul 2003 08:20:35 +0100
From: foo <foo@bar.com>
Subject: Re: How to match all characters in a Character Class
Message-Id: <1058512833.458132@ananke.eclipse.net.uk>
Eric Schwartz wrote:
>>>Is there a way in Perl to match all the characters in the Character
>>>Class?
.* will do it.
> No, that matches any single character. The OP was asking about
> character classes, such as [a0-9q] and [:space:], and so forth. To do
Are sure? I reads more like the OP belives there is 'Character class'
construct.
> that, you'd need a way to enumerate them ...
([:alpha:]|[:alnum:]|[:ascii:]|[:blank:]|[:cntrl:]|[:digit:]|[:graph:]|[:lower:]|[:print:]|[:punct:]|[:space:]|[:upper:]|[:word:]|[:xdigit:])
jimbo
;-)
------------------------------
Date: Fri, 18 Jul 2003 06:24:14 +0200
From: "Janek Schleicher" <bigj@kamelfreund.de>
Subject: Re: HTML REGEX
Message-Id: <pan.2003.07.18.04.19.00.434799@kamelfreund.de>
Brendan Byrd/SineSwiper wrote at Fri, 18 Jul 2003 00:22:34 +0000:
> Boudga wrote:
>
>> I want to remove the Style tags from my HTML files so I wrote this Perl
>> script to remove the line breaks and attempt to remove the Style tags but it
>> fails....any help would be much appreciated!
>
> I've got one that does that:
>
> $j =~ s/<+\s*STYLE(.*?)>+.+<+\s*\/STYLE(.*?)>+//gis
^^
.+?
>
> Should remove the style tags and any contents thereof.
In the hope that there are not more than only one style elements
(what is to be fair really rare).
Greetings,
Janek
------------------------------
Date: Fri, 18 Jul 2003 05:26:28 -0400
From: Ted Zlatanov <tzz@lifelogs.com>
Subject: Re: macros in perl
Message-Id: <4nd6g8jid7.fsf@lockgroove.bwh.harvard.edu>
On 17 Jul 2003, tassilo.parseval@rwth-aachen.de wrote:
> Also sprach Ted Zlatanov:
>
>> Another problem with the sort of macros you imagine is that they
>> don't really help you, and in fact may prevent you from learning
>> the better idioms that people have pointed out already. Whereas C
>> can definitely benefit from macros, Perl is (in my experience) not
>> a repetitive language because of its rich syntax; if you find
>> yourself repeating things so you need a macro it's time to write a
>> subroutine.
>
> Functions do not serve the same purpose as macros. If they did, you
> wouldn't need macros in C.
Absolutely. I was specifically referring to the OP's macros in Perl.
I thought that was clear because I continued the thought in the same
sentence. What I mean is that generally C-style macros (for instance
the byte ordering you mention) are unnecessary in Perl or can be
expressed as subroutines. The need for actual compile-time expansion
in Perl, such as what the Switch module does and Perl 6 will provide,
is very rare.
Ted
------------------------------
Date: Fri, 18 Jul 2003 08:50:13 +0200
From: Eric Moors <scare.crow@oz.land>
Subject: Re: perlstyles
Message-Id: <pan.2003.07.18.08.50.12.431359.29043@oz.land>
On Fri, 18 Jul 2003 01:02:46 +0200, Steven Kuo wrote:
> my %hash = (
> t10 => 'Tiger',
> t20 => 'Turtle',
> u10 => 'Urchin',
> v10 => 'Viper', # !! does not quote LHS of => !!
> );
>
> print keys %hash;
Why is this?
I couldn't find anyting about it with perldoc.
Eric
------------------------------
Date: Fri, 18 Jul 2003 08:43:54 GMT
From: tiltonj@erols.com (Jay Tilton)
Subject: Re: perlstyles
Message-Id: <3f17b2cc.112902316@news.erols.com>
Eric Moors <scare.crow@oz.land> wrote:
: On Fri, 18 Jul 2003 01:02:46 +0200, Steven Kuo wrote:
:
: > my %hash = (
: > t10 => 'Tiger',
: > t20 => 'Turtle',
: > u10 => 'Urchin',
: > v10 => 'Viper', # !! does not quote LHS of => !!
: > );
: >
: > print keys %hash;
:
: Why is this?
: I couldn't find anyting about it with perldoc.
See perldata. Scan for "v-strings".
------------------------------
Date: Fri, 18 Jul 2003 11:13:00 +0200
From: Matija Papec <mpapec@yahoo.com>
Subject: Re: perlstyles
Message-Id: <g6efhv8fbg17girp52qnmkuh0hi3oee0a1@4ax.com>
X-Ftn-To: parv
parv <parv_fm@emailgroupsWhereElse.net> wrote:
>> #2
>> @arr = join(',', map(s|'|\\'|g && "'$_'", grep(/^MB/, @arr)));
>
>In this case, i would like to show that the output place is same as
>input (use of map/grep BLOCK is intentional to avoid distracting
>commas & parentheses)...
>
> @arr = join ',' , map { s/'/\\'/g; "'$_'" }
> grep { /^MB/ }
> @arr;
>
>
>Number & position of parentheses depends on what is being emphasized,
>need to preserve order of execution, and grouping of pieces in a
>larger expression. Example of the last criterion...
>
> @arr =
> join ',' , map ( s/'/\\'/g && "'$_'" ) , (grep ( /^MB/ ) , @arr);
>
>(I maintain only my own code, what would i know.)
:)
>> and another one, how do you prefer $h{key} over $h{'key'} in case
>> where key is strictly English \w class?
>
>I used to use bare keys, but after the irritating error message about
>usage of a key w/ a hyphen in its name, i use quoted keys w/o
>exception.
That makes sense, but afaik you shouldn't have problems with
%h = (-foo => 'bar');
What is your perl version?
--
Matija
------------------------------
Date: Fri, 18 Jul 2003 11:12:56 +0200
From: Matija Papec <mpapec@yahoo.com>
Subject: Re: perlstyles
Message-Id: <8cefhv0aosmk244to8b4cql6un7mgb8bd4@4ax.com>
X-Ftn-To: Uri Guttman
Uri Guttman <uri@stemsystems.com> wrote:
> MP> I prefer first as it's far more obvious what's going on(not to
> MP> mention typing laziness), but that's just me.
>
> MP> #1
> MP> @arr = join ',', map s|'|\\'|g && "'$_'", grep /^MB/, @arr;
> MP> #2
> MP> @arr = join(',', map(s|'|\\'|g && "'$_'", grep(/^MB/, @arr)));
>
>when using nested stuff like that, i usually prefer parens to help
>out. but i am not strict about it. it may depend subtly on the actual
>code and my mood.
It appears to me that thinking in terms of 'chained lists' lead to faster
code understanding as opposed to nested thinking. For example,
$s = join ',',
map { s|'|\\'|g && "'$_'" }
grep { /^MB/ } @arr;
is very easy to follow from right/bottom to left/top, and if we add another
map and sort to it, it would still be easy on the eyes.
> MP> and another one, how do you prefer $h{key} over $h{'key'} in case
> MP> where key is strictly English \w class?
>
>i prefer quotes all the time for fixed string hash keys. combination of
>old habit and being cautious. i have seen issues where a key was also a
>function name and with quotes you know which one it is (even if it works
>the way you want).
Hm, under which circumstances is key interpreted as sub? I just tried,
sub key { return 'gotcha' }
$Q{key} = 11;
print join('=>', %Q), "\n";
and it prints 'key=>11'?
btw, is there some "use" clause which favores plain keys over subs with same
names?
> MP> a clue about use strict and warnings, and at the same time
> MP> insisting on quoted hash keys? :)
>
>that is another matter and i don't know the person. the size of the
>cluebat you use will be critical. :)
And I'm afraid, if all else fails one can always turn to more persuasive
kind of bats. <g>
--
Matija
------------------------------
Date: Fri, 18 Jul 2003 11:26:06 +0200
From: Eric Moors <scare.crow@oz.land>
Subject: Re: perlstyles
Message-Id: <pan.2003.07.18.11.26.06.218973.30512@oz.land>
On Fri, 18 Jul 2003 10:43:54 +0200, Jay Tilton wrote:
> Eric Moors <scare.crow@oz.land> wrote:
>
> : On Fri, 18 Jul 2003 01:02:46 +0200, Steven Kuo wrote:
> :
> : > my %hash = (
> : > t10 => 'Tiger',
> : > t20 => 'Turtle',
> : > u10 => 'Urchin',
> : > v10 => 'Viper', # !! does not quote LHS of => !!
> : > );
> : >
> : > print keys %hash;
> :
> : Why is this?
> : I couldn't find anyting about it with perldoc.
>
> See perldata. Scan for "v-strings".
v-strings doesn't occur in the perldata manpage I have.
(searching for "version number" would have been a better hint)
But I found an explanation in my copy of "Programming Perl"
v10 gets transformed into newline.
Eric
------------------------------
Date: Fri, 18 Jul 2003 06:24:17 +0200
From: "Janek Schleicher" <bigj@kamelfreund.de>
Subject: Re: perlstyles
Message-Id: <pan.2003.07.18.03.44.22.45903@kamelfreund.de>
parv wrote at Fri, 18 Jul 2003 03:14:08 +0000:
> in message <g1udhv065eijbi9kd4flhr3k2o1n19uoa7@4ax.com>,
> wrote Matija Papec ...
>
>> #1
>> @arr = join ',', map s|'|\\'|g && "'$_'", grep /^MB/, @arr;
>> #2
>> @arr = join(',', map(s|'|\\'|g && "'$_'", grep(/^MB/, @arr)));
>
>
> In this case, i would like to show that the output place is same as
> input (use of map/grep BLOCK is intentional to avoid distracting
> commas & parentheses)...
>
> @arr = join ',' , map { s/'/\\'/g; "'$_'" }
^^
That is very different from the OP's &&.
In your solution, every element of the array is mapped into enclosing
single quotes, while in the OP's code, an element is only enclosed by
single quotes if there had been any single quote inside the element
before.
I don't know whether it is a problem for the OP, but at least, it's a
little difference
> grep { /^MB/ }
> @arr;
Greetings,
Janek
------------------------------
Date: Fri, 18 Jul 2003 06:24:17 +0200
From: "Janek Schleicher" <bigj@kamelfreund.de>
Subject: Re: perlstyles
Message-Id: <pan.2003.07.18.04.15.39.483452@kamelfreund.de>
Matija Papec wrote at Thu, 17 Jul 2003 22:27:08 +0200:
> I was wandering what would be more readable for code maintainers, I prefer
> first as it's far more obvious what's going on(not to mention typing
> laziness), but that's just me.
>
> #1
> @arr = join ',', map s|'|\\'|g && "'$_'", grep /^MB/, @arr;
^^^^ ^^^^
An array
result is a string!
> #2
> @arr = join(',', map(s|'|\\'|g && "'$_'", grep(/^MB/, @arr)));
I wouldn't look so much to the brackets regarding for code maintainers.
It is easy and simple to understand that both lines
do a comma-join over all transformed elements of @arr that starts with MB.
What is hard to understand on the first view is the transformation that
has to be done. You first need to think some seconds only to comprehend it. And
even if you did it, you can't be sure whether the implemented algorithm
was also the intended one. That is dangerous for maintainance.
I think it would be better to write a subroutine doing exactly this
transformation. If the subroutine has a sensful name, the maintainer can
read and understand without any thinking what the line does. In addition,
he/she can decide whether the transformation does what the subroutine name
says or a completely different transformation will be needed instead.
Let's say something like:
sub escape_single_quotes($) {
my $string = shift;
$string =~ s,',\\',g
and return qq/'$string'/
or return $string;
}
my $str = join ",", map escape_single_quotes($_), grep /^MB/, @arr;
Note, that I also did two other slight changes.
First I changed the pipe symbol to a comma in the substitution.
Not that the comma is so much better, but IMHO the pipe is that worse,
as it is also the alternation operator with such a special meaning in
substitutions, that it is very confusing (and thus less readable) if it
is used as delimiters in regexps.
Second I wrote "'$string'" as qq/'$string'/. I wanted to emphasize that
the returned value is in principle the '$string' in contrast to the simple
$string. I prefer not to have "' or '" in a text as single and double
quotes look similar and are hard to distinguish if they are very near in
the next. (But that's perhaps more a personal style than a hard
maintainance demand)
> and another one, how do you prefer $h{key} over $h{'key'} in case where key
> is strictly English \w class?
Both doesn't matter for readability and maintainance. I, personally, wouldn't write
$h{'key'} where it isn't necessary (main reason is laziness),
but both ways are easy to read, understand and change.
> Most importantly, what would you tell to someone who doesn't have a clue
> about use strict and warnings, and at the same time insisting on quoted hash
> keys? :)
Who has no clue about strict and warnings, should not maintain my code!
Greetings,
Janek
------------------------------
Date: Fri, 18 Jul 2003 02:22:36 -0500
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.4 $)
Message-Id: <_7CcndYfLcShPYqiXTWJjA@august.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.4 $)
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.
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
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Do *NOT* send email to the maintainer of these guidelines. It will be
discarded unread. The guidelines belong to the newsgroup so all
discussion should appear in the newsgroup. I am just the secretary that
writes down the consensus of the group.
Before posting to comp.lang.perl.misc
Must
This section describes things that you *must* do before posting to
clpmisc, in order to maximize your chances of getting meaningful replies
to your inquiry and to avoid getting flamed for being lazy and trying to
have others do your work.
The perl distribution includes documentation that is copied to your hard
drive when you install perl. Also installed is a program for looking
things up in that (and other) documentation named 'perldoc'.
You should either find out where the docs got installed on your system,
or use perldoc to find them for you. Type "perldoc perldoc" to learn how
to use perldoc itself. Type "perldoc perl" to start reading Perl's
standard documentation.
Check the Perl Frequently Asked Questions (FAQ)
Checking the FAQ before posting is required in Big 8 newsgroups in
general, there is nothing clpmisc-specific about this requirement.
You are expected to do this in nearly all newsgroups.
You can use the "-q" switch with perldoc to do a word search of the
questions in the Perl FAQs.
Check the other standard Perl docs (*.pod)
The perl distribution comes with much more documentation than is
available for most other newsgroups, so in clpmisc you should also
see if you can find an answer in the other (non-FAQ) standard docs
before posting.
It is *not* required, or even expected, that you actually *read* all of
Perl's standard docs, only that you spend a few minutes searching them
before posting.
Try doing a word-search in the standard docs for some words/phrases
taken from your problem statement or from your very carefully worded
"Subject:" header.
Really Really Should
This section describes things that you *really should* do before posting
to clpmisc.
Lurk for a while before posting
This is very important and expected in all newsgroups. Lurking means
to monitor a newsgroup for a period to become familiar with local
customs. Each newsgroup has specific customs and rituals. Knowing
these before you participate will help avoid embarrassing social
situations. Consider yourself to be a foreigner at first!
Search a Usenet archive
There are tens of thousands of Perl programmers. It is very likely
that your question has already been asked (and answered). See if you
can find where it has already been answered.
One such searchable archive is:
http://groups.google.com/advanced_group_search
If You Like
This section describes things that you *can* do before posting to
clpmisc.
Check Other Resources
You may want to check in books or on web sites to see if you can
find the answer to your question.
But you need to consider the source of such information: there are a
lot of very poor Perl books and web sites, and several good ones
too, of course.
Posting to comp.lang.perl.misc
There can be 200 messages in clpmisc in a single day. Nobody is going to
read every article. They must decide somehow which articles they are
going to read, and which they will skip.
Your post is in competition with 199 other posts. You need to "win"
before a person who can help you will even read your question.
These sections describe how you can help keep your article from being
one of the "skipped" ones.
Is there a better place to ask your question?
Question should be about Perl, not about the application area
It can be difficult to separate out where your problem really is,
but you should make a conscious effort to post to the most
applicable newsgroup. That is, after all, where you are the most
likely to find the people who know how to answer your question.
Being able to "partition" a problem is an essential skill for
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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
"Jeopardy" (because the answer comes before the question), or
"TOFU".
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: 18 Jul 2003 04:49:19 GMT
From: "Tassilo v. Parseval" <tassilo.parseval@rwth-aachen.de>
Subject: Re: Removing Perl comments and strings using regexps
Message-Id: <bf7u8f$ntj$1@nets3.rz.RWTH-Aachen.DE>
Also sprach Brendan Byrd/SineSwiper:
> Jay Tilton wrote:
>
>> Brendan Byrd/SineSwiper <SineSwiper@ResonatorSoft.org> wrote:
>>
>> : I'm in the middle of fixing the LXR tool to work with Perl. Almost
>> : finished, but I've ran into a problem that completely fries my brain.
>> : In order to detect Perl subroutine/variable declarations, I need to
>> : remove comments and strings so that they don't get confused for
>> : declarations.
>>
>> How about just running the program through the Xref backend?
>>
>> perl -MO=Xref foo.pl
>>
>
> Interesting. Is there a way to load that as a module and send the input
> of a variable (the program) to Xref?
If such a way existed, I'd like to know it, too. How I understand the
B:: modules and the generic compiler backend O there is no such way.
They are triggered in a CHECK block right after a script has been
compiled. A B:: module simply provides a callback that is invoked on the
optree of a script. So it can't work on strings.
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: 18 Jul 2003 01:29:56 -0700
From: ziphem@hotmail.com (Bill S.)
Subject: Writing Javascript and some Style into .CGI?
Message-Id: <21ee69a6.0307180029.6173b5f9@posting.google.com>
I have been trying to figure out how to write JavaScript and some
<style> stuff to display with my CGI file. I have been trying to
figure it out for a long time, but can't seem to make sense of it!
Here's what I tried - can someone tell me what I did wrong and point
me in the right direction?
Thanks a lot!!
::::CODE BELOW::::
sub write_js {
print <<END_OF_JS;
<SCRIPT>
function writestatus(say) { self.status="Terriblemovies.com [" + say +
"]"; } function clearstatus() {
self.status="Terriblemovies.com"; }
clearstatus();
</SCRIPT>
END_OF_JS
} sub write_html {
print <<END_OF_HTML;
<Style Type="text/css"><!--
Body { scrollbar-arrow-color:WHITE; scrollbar-track-color:white;
scrollbar-shadow-color:#D6D6D6;
scrollbar-face-color:#135184; scrollbar-highlight-color:#D6D6D6;
scrollbar-darkshadow-color:#135184;
scrollbar-3dlight-color:#135184; }
--></Style>
<body bgcolor="ffffff" TEXT="000000" LINK="#FF0000" ALINK="ffff00"
VLINK="#FF0000" background="background.gif">
<FONT SIZE=-1> <font color="white">
</font></font>
<style type="text/css"><!--
A:link {color: #000000; text-decoration: none; font-weight: 300;}
A:visited {color: #666699; text-decoration: none; font-weight: 300;}
A:hover {color: blue; text-decoration: underline; font-weight: 300;}
//--></style>
END_OF_HTML
}
------------------------------
Date: Fri, 18 Jul 2003 05:37:25 +0200
From: "Janek Schleicher" <bigj@kamelfreund.de>
Subject: Re: Writing Javascript and some Style into .CGI?
Message-Id: <pan.2003.07.18.03.37.23.295563@kamelfreund.de>
Bill S. wrote at Fri, 18 Jul 2003 01:29:56 -0700:
> I have been trying to figure out how to write JavaScript and some
> <style> stuff to display with my CGI file. I have been trying to
> figure it out for a long time, but can't seem to make sense of it!
> Here's what I tried - can someone tell me what I did wrong and point
> me in the right direction?
What let you assume that you did something wrong.
You show us two syntactical correct subroutines,
no main program,
no error message,
no expected in- and output,
no false output.
We can't know whether there is a syntactical or logical Perl error, nor a
JavaScript error, nor an Apache configuration error, nor a Browser bug,
nor a problem in your algorithm, nor anything else without enough
information.
Greetings,
Janek
------------------------------
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>
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------------------------------
End of Perl-Users Digest V10 Issue 5236
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