[19542] in Perl-Users-Digest
Perl-Users Digest, Issue: 1737 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Wed Sep 12 18:05:57 2001
Date: Wed, 12 Sep 2001 15:05:10 -0700 (PDT)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Message-Id: <1000332310-v10-i1737@ruby.oce.orst.edu>
Content-Type: text
Perl-Users Digest Wed, 12 Sep 2001 Volume: 10 Number: 1737
Today's topics:
Accessing a webserver from a perl program? <one@two.com>
Re: Accessing a webserver from a perl program? (John J. Trammell)
Re: Accessing a webserver from a perl program? <simon.oliver@umist.ac.uk>
Re: Accessing a webserver from a perl program? (Tad McClellan)
create acct locally on PCs for whole domain (Geoff Rothman)
Re: DBI prepare ... with bind_param or execute ? <fty@mediapulse.com>
Re: DBI prepare ... with bind_param or execute ? <gnarinn@hotmail.com>
Match the contents of HTML comment <blackgoblin@spammail.com>
Re: Match the contents of HTML comment (Tad McClellan)
Passing a parameter from a text file???? <acoustic_bill@yahoo.com>
Re: Passing a parameter from a text file???? <rsherman@ce.gatech.edu>
Re: Perl is TOO much fun <iltzu@sci.invalid>
Re: Perl is TOO much fun (Malcolm Dew-Jones)
Re: PERL modules and GPL license <newspost@coppit.org>
Re: PERL modules and GPL license (Malcolm Dew-Jones)
Re: Perl script to count pages in a pdf file <yanoff@yahoo.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Printing in Perl (Graham W. Boyes)
Re: Printing in Perl (Logan Shaw)
Problem after Alarm interrupts system call <kirk@wuffo.togetherweb.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Wed, 12 Sep 2001 15:22:27 +0200
From: "Just Some Guy" <one@two.com>
Subject: Accessing a webserver from a perl program?
Message-Id: <9nnned$j7m$1@mosquito.HL.Siemens.DE>
Hi,
I would appreciate any information on how to access a webserver from a perl
program. Something like accessing port 80, sending a request to the http
address and receiving a response. Any information or examples on how to
achieve this would be appreciated. The perl program will be run from a linux
box.
Thanks in advance.
With kind regards,
Me, Myself and I.
------------------------------
Date: 12 Sep 2001 13:43:02 GMT
From: trammell@haqq.hypersloth.invalid (John J. Trammell)
Subject: Re: Accessing a webserver from a perl program?
Message-Id: <slrn9pupj6.57n.trammell@haqq.hypersloth.net>
On Wed, 12 Sep 2001 15:22:27 +0200, Just Some Guy <one@two.com> wrote:
> I would appreciate any information on how to access a webserver from a perl
> program. Something like accessing port 80, sending a request to the http
> address and receiving a response. Any information or examples on how to
> achieve this would be appreciated. The perl program will be run from a linux
> box.
This is answered in Perl FAQ #9 ("How do I fetch an HTML file?").
You are expected to read the relevant FAQ(s) before posting to any
newsgroup.
--
Only a very small fraction of our DNA does anything; the rest is all
comments and ifdefs.
------------------------------
Date: Wed, 12 Sep 2001 16:07:00 +0100
From: "Simon Oliver" <simon.oliver@umist.ac.uk>
Subject: Re: Accessing a webserver from a perl program?
Message-Id: <3b9f7d5e$1@news.umist.ac.uk>
LWP::Simple or LWP::UserAgent or Net::Telnet or HTTP::Request
--
Simon Oliver
"Just Some Guy" <one@two.com> wrote in message
news:9nnned$j7m$1@mosquito.HL.Siemens.DE...
> Hi,
>
> I would appreciate any information on how to access a webserver from a
perl
> program. Something like accessing port 80, sending a request to the http
> address and receiving a response. Any information or examples on how to
> achieve this would be appreciated. The perl program will be run from a
linux
> box.
>
> Thanks in advance.
>
> With kind regards,
> Me, Myself and I.
>
>
------------------------------
Date: Wed, 12 Sep 2001 15:20:01 GMT
From: tadmc@augustmail.com (Tad McClellan)
Subject: Re: Accessing a webserver from a perl program?
Message-Id: <slrn9puseq.9vq.tadmc@tadmc26.august.net>
Just Some Guy <one@two.com> wrote:
>
>I would appreciate any information on how to access a webserver from a perl
>program.
Use one of the modules from this package:
http://search.cpan.org/search?mode=dist&query=libwww
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
Date: 12 Sep 2001 12:45:30 -0700
From: rothman@pobox.com (Geoff Rothman)
Subject: create acct locally on PCs for whole domain
Message-Id: <a4f5b2c8.0109121145.1011e858@posting.google.com>
I want to use Perl (and probably a few modules) to add an account with local
Administrator privileges called "pcadmin" to every computer in a domain. If
it's unsuccessful, I'll print the computername to a file. I will run this
script one time on an acct that has domain admin privileges.
Can i get some help?
thanks!
geoff
------------------------------
Date: Wed, 12 Sep 2001 13:49:06 GMT
From: "Jay Flaherty" <fty@mediapulse.com>
Subject: Re: DBI prepare ... with bind_param or execute ?
Message-Id: <mJJn7.298922$NK1.27431410@bin3.nnrp.aus1.giganews.com>
"Barghest" <barghest@wanadoo.fr> wrote in message
news:9nnbth$a8l$1@reader1.imaginet.fr...
> Hi,
>
> What's the best, or what's the real difference between:
> $sth->bind_param( 1, "aaa" );
> $sth->bind_param( 2, "bbb" );
> $sth->execute();
>
> and this one
> $sth->execute( "aaa", "bbb" );
> } # reading file
None. In the execute method, if any arguments are given then execute will
effectively call bind_param for each value before executing the statement.
Values bound this way are usually trated as SQL_VARCHAR types. Using
bind_param gives you the opportunity to set the datatype of the value by
passing a datatype hash {TYPE => SQL_INTEGER}
Jay
------------------------------
Date: Wed, 12 Sep 2001 19:03:22 +0000
From: gnari <gnarinn@hotmail.com>
Subject: Re: DBI prepare ... with bind_param or execute ?
Message-Id: <1000321402.633913136553019.gnarinn@hotmail.com>
In article <9nnbth$a8l$1@reader1.imaginet.fr>,
Barghest <barghest@wanadoo.fr> wrote:
>Hi,
>
>What's the best, or what's the real difference between:
>
>$sth = $dbh->prepare( "insert into stuff.table ( foo, fii ) value ( ?,
>? )" );
>...
>while < reading a file > {
>this one # that's what i'm doing actually
>$sth->bind_param( 1, "aaa" );
>$sth->bind_param( 2, "bbb" );
>$sth->execute();
>
>and this one
>$sth->execute( "aaa", "bbb" );
>} # reading file
>
i usually use the second method, unless i need to give a 3rd argument
to bind_param(). if you read perldoc DBI, you might have seen that the
execute() with arguments actually calls bind_param(). the difference
in effectivity should be marginal compared to database access in any case.
gnari
------------------------------
Date: Tue, 11 Sep 2001 12:15:43 +0100
From: "Goblin" <blackgoblin@spammail.com>
Subject: Match the contents of HTML comment
Message-Id: <9nks64$6i9$1@venus.telepac.pt>
Hello everybody,
I've been wracking my brain over a way to match a HTML comment and get its
contents. Right now I have something like:
m/^\s*<!--(^W*|^w*)(?=\s*-->)\s*$/gmx
. . . only it doesn't work, of course. Can any of you give me a hand?
Cheers, and thanks in advance for any and all help,
G.
------------------------------
Date: Wed, 12 Sep 2001 21:41:07 GMT
From: tadmc@augustmail.com (Tad McClellan)
Subject: Re: Match the contents of HTML comment
Message-Id: <slrn9pvgtn.ain.tadmc@tadmc26.august.net>
Goblin <blackgoblin@spammail.com> wrote:
>
>I've been wracking my brain over a way to match a HTML comment and get its
>contents.
Use a module that understands HTML for processing HTML.
>m/^\s*<!--(^W*|^w*)(?=\s*-->)\s*$/gmx
^^ ^^
^^ ^^ spaces are allowed there
That pattern can *never* match. You aren't going to match
"beginning of line" after requiring the previous character
to be something other than \n.
What are the carets in (^W*|^w*) meant to be doing? I am pretty
sure they are not doing whatever that is :-)
>. . . only it doesn't work, of course. Can any of you give me a hand?
Give up on using a regular expression, it ain't gonna work.
This Perl FAQ is pertinent:
"How do I remove HTML from a string?"
But you have no doubt already seen that. So why insist on trying
to do it with mere pattern matching?
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
Date: Wed, 12 Sep 2001 16:04:27 -0500
From: "Bill Thomas" <acoustic_bill@yahoo.com>
Subject: Passing a parameter from a text file????
Message-Id: <tpvjet25f1dfa9@corp.supernews.com>
Any help will be greatly appreciated even if it is just reference to some
good documentation or examples.
I am pretty new to Perl and could use a little help.
I need to execute a program several times and pass different parameters to
it each time.
Example: I need to execute program 'foo' with the static parameter 'bar'
sun:/foo bar
but I also need to pass some parameters that are stored in a text file which
is formatted like:
go home
get something
run away
So the final result should be that the program executes 3 times like:
sun:/foo bar go home
sun:/foo bar get something
sun:/foo bar run away
The parameter file will change in number of entries.
Any help will be greatly appreciated even if it is just reference to some
good documentation or examples.
------------------------------
Date: Wed, 12 Sep 2001 17:21:04 +0500
From: Robert Sherman <rsherman@ce.gatech.edu>
Subject: Re: Passing a parameter from a text file????
Message-Id: <3B9F5330.3ED01E25@ce.gatech.edu>
Bill Thomas wrote:
>
> Any help will be greatly appreciated even if it is just reference to some
> good documentation or examples.
>
> I am pretty new to Perl and could use a little help.
> I need to execute a program several times and pass different parameters to
> it each time.
assuming you are using perl to write a wrapper for a compiled program
(your post wasn't too clear on what 'foo' is):
make a text file arguments.txt with one argument per line
--------------------------------------
open FILE, "arguments.txt";
while (<FILE>){
chomp;
$result = `foo bar $_`;
#maybe do something with $result here
}
--------------------------------------
--
robert sherman
css, cee
georgia institute of technology
atlanta, ga, usa
------------------------------
Date: 12 Sep 2001 21:35:26 GMT
From: Ilmari Karonen <iltzu@sci.invalid>
Subject: Re: Perl is TOO much fun
Message-Id: <1000330268.27642@itz.pp.sci.fi>
In article <776e0325.0109081839.55041721@posting.google.com>, Sara wrote:
>I dunno why - coding this just makes me giggle! Ya gotta love this language..
>
> my @p=<*.jpg>;
> my %p;
> @p{@p}=@p;
TIMTOWTDI...
my %p = map +($_)x2, <*.jpg>;
--
Ilmari Karonen -- http://www.sci.fi/~iltzu/
"Get real! This is a discussion group, not a helpdesk. You post something,
we discuss its implications. If the discussion happens to answer a question
you've asked, that's incidental." -- nobull in comp.lang.perl.misc
------------------------------
Date: 12 Sep 2001 14:58:40 -0800
From: yf110@vtn1.victoria.tc.ca (Malcolm Dew-Jones)
Subject: Re: Perl is TOO much fun
Message-Id: <3b9fda90@news.victoria.tc.ca>
Uri Guttman (uri@sysarch.com) wrote:
: >>>>> "S" == Sara <genericax@hotmail.com> writes:
: S> I dunno why - coding this just makes me giggle! Ya gotta love this
: S> language.. -WQ
: then join the fun with perl list (see lists.perl.org).
: S> my @p=<*.jpg>;
: S> my %p;
: S> @p{@p}=@p;
: you shouldn't be using single letter var names and having a hash and an
: array with the same name is fun but not good solid coding.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
that's right!
@INC %INC
@ARGV $ARGV
etc etc etc
:)
------------------------------
Date: Wed, 12 Sep 2001 08:59:53 -0400
From: David Coppit <newspost@coppit.org>
Subject: Re: PERL modules and GPL license
Message-Id: <3B9F5C49.8090508@coppit.org>
Stefan Weiss wrote:
> From: "Randal L. Schwartz" <merlyn@stonehenge.com>
>
>>Almost everything in the CPAN says "distributed under the same
>>licensing terms as Perl itself". If that's the case, it's under both
>>the GPL and the AL. The GPL would (likely) not permit you to do what
>>you ask, but the AL certainly would, as long as you don't call the
>>result "Perl".
>>
>>This is one of the coolest things about the Perl CPAN... we can indeed
>>do nearly everything we want to do. :)
>
> I've been wondering about this for some time: how can the GPL coexist
> with any other license in a statement like "may be distributed under
> the same terms as Perl itself"?
Good question. I think you can pick which license you want. Anyone have
more data?
> | Perl may be copied only under the terms of either the Artistic
> | License or the GNU General Public License, which may be found in
> | the Perl 5 source kit.
>
> I thought that once a program has been distributed under the GPL once,
> you would have to stick to the GPL. So who can choose which licence
> such a module is distributed with? The author? The distributor? The user?
The copyright holder, who is usually the author. Remember, when I
license code, I'm licensing *the text* of the code. I could change the
license in the next version, or even relicense the current version. This
is what happens with the ghostscript code. Artifex will develop new code
under a proprietary license, then release that code under an open source
license after a period of time has expired. This gives them a
technological edge before their product is obsoleted by the open source
variant.
> Somebody ports perl to a new OS and decides to distribute this perl
> version under the GPL (and no mention about the AL). Perl's licence
> would allow him to do that, I think.
No... The license doesn't say "you can change the license". :)
>
If I was going to use a module
> with this perl version that had a note about being "distributed under
> the same terms as Perl itself", would I *have* to use it under the GPL,
> or could I still take the AL?
I always thought that this phrase was a lazy error-prone one. A possible
alternative scenario is that Larry decide he doesn't like the AL anymore
and goes straight GPL. I'm guessing that the phrase would then be
interpreted as "distributed under the same terms as Perl itself, as of
the date of this code release"
David
------------------------------
Date: 12 Sep 2001 13:18:06 -0800
From: yf110@vtn1.victoria.tc.ca (Malcolm Dew-Jones)
Subject: Re: PERL modules and GPL license
Message-Id: <3b9fc2fe@news.victoria.tc.ca>
Mark Jason Dominus (mjd@plover.com) wrote:
: In article <3b9e5021@news.victoria.tc.ca>,
: Malcolm Dew-Jones <yf110@vtn1.victoria.tc.ca> wrote:
: >"Link" is a technical term, which has quite specific meanings.
: I find it difficult to respond to this article, because you seem make
: several logically inconsistent arguments at several different places.
Yes, my mistake.
: I must say though, that if I were in Sammi's position, I would not
: want to take the risk that I would be exposed to liability because I
: had taken the advice of some random guy name Malcolm who said that
: nobody knew what the license meant, when there was an available legal
: opinion that said otherwise.
I would not suggest he do that either, because my concern is exactly the
reverse.
My concern is that if you write a GPL'd module then it may not have the
protection you think it has when applied to a language like perl. Notice
that the FSF has always chosen to distribute a clarification with Bison to
ensure the GPL must be interpreted in the manner they wish. Why? -
perhaps because not all of them are convinced that the unclarified GPL is
enough to ensure the code is protected in a potentially ambiguous
situation.
------------------------------
Date: Wed, 12 Sep 2001 12:50:30 -0500
From: Scott Yanoff <yanoff@yahoo.com>
To: Ofuuzo <ofuuzo@ub.uit.no>
Subject: Re: Perl script to count pages in a pdf file
Message-Id: <3B9FA066.F47A8AEF@yahoo.com>
Ofuuzo wrote:
>
> Hi,
>
> Is there any perl script to find out the total number of pages in a PDF
> file?
You can get the PDF.pm module from http://cpan.org
It includes an example script called "pdf_pages" that will do what you
need.
Good luck,
--
-Scott
yanoff@yahoo.com | http://www.yanoff.org | AOL IM: SAY KJY
------------------------------
Date: Wed, 12 Sep 2001 21:46:57 GMT
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.2 $)
Message-Id: <lJQn7.459162$ai2.34326261@bin2.nnrp.aus1.giganews.com>
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: 1.2 $)
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":
Please do not use the existence of these guidelines as a
"license to flame" or other meanness. It is possible that
a poster is not aware of the things discussed here. Let's
give them the benefit of the doubt, and just help them learn
how to post, rather than assume that they do know and are
being the "bad kind" of Lazy.
A note about technical terms used here:
In this document, we use words like "must" and "should" in the
very precise sense that they're used in technical conversation
(such as you're likely to 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 very unlikely that you're going to
get much benefit from using this group. We're not trying to boss
you around; we're just trying to convey the point without using
a lot 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 is expected regardless of what newsgroup
you are visiting. Lurking means to simply monitor a newsgroup for a
period of time until you become very familiar with local customs.
Think of a newsgroup as foreign culture. Each newsgroup has its own
specific customs and rituals. Get to know those customs and rituals
well before you participate. This will help you to 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.perl.com/CPAN-local/authors/Dean_Roehrich/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* the sections of quoted text
that your comments apply to. Failure to do this is called "Jeopardy"
posting because the answer comes before the question.
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://www.geocities.com/nnqweb/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: 12 Sep 2001 11:10:02 -0700
From: thepro@toao.net (Graham W. Boyes)
Subject: Printing in Perl
Message-Id: <e9503d3c.0109121010.114ce7d1@posting.google.com>
Hi,
I'm trying to print a few lines of text from within a Perl script.
The data is sent to my printer (HP LaserJet 5N) and the display shows
"Data Received". But I have to hit the "Go" button on the printer
before it will print it.
Is there some sort of termination command I need to send?
Thanks,
Graham W. Boyes
------------------------------
Date: 12 Sep 2001 16:01:16 -0500
From: logan@cs.utexas.edu (Logan Shaw)
Subject: Re: Printing in Perl
Message-Id: <9noies$jgi$1@charity.cs.utexas.edu>
In article <e9503d3c.0109121010.114ce7d1@posting.google.com>,
Graham W. Boyes <thepro@toao.net> wrote:
>I'm trying to print a few lines of text from within a Perl script.
>The data is sent to my printer (HP LaserJet 5N) and the display shows
>"Data Received". But I have to hit the "Go" button on the printer
>before it will print it.
>
>Is there some sort of termination command I need to send?
Is there some sort of information you want to give us about what
operating system you're using and/or how you're trying to send to the
printer (over the network, through the OS's queuing system, etc.)?
- Logan
--
"Our grandkids love that we get Roadrunner and digital cable."
(Advertisement for Time Warner cable TV and internet access, July 2001)
------------------------------
Date: Wed, 12 Sep 2001 17:40:40 GMT
From: Kirk Bauer <kirk@wuffo.togetherweb.com>
Subject: Problem after Alarm interrupts system call
Message-Id: <s6Nn7.254$yc3.144399@newsfeed.slurp.net>
The following simple program illustrates a problem I have.
If SIGALRM interrupts the "system" command, then all
signals from then on appear to be ignored.
while (1) {
eval {
# Set a timeout
local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required
alarm 5;
# If you use the "sleep" command, everything works fine
#sleep 10;
# But, if you use the "system" command, all interrupts seem to not work
system("sleep 10");
# Disable timeout
alarm 0;
};
if ($@) {
print "Got here: $@";
die unless $@ eq "alarm\n"; # propagate unexpected errors
# timed out
print "Timed out... now CTRL-C will not kill the program\n";
}
sleep (1);
}
Any help you could give me would be greatly appreciated!
This problem happens on both:
perl-5.6.0
perl-5.00503
--
Kirk Bauer <kirk@togetherweb.com> (404) 817-8158 x202
Chief Technology Officer, TogetherWeb Inc
------------------------------
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 1737
***************************************
