[25147] in Perl-Users-Digest
Perl-Users Digest, Issue: 7396 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Nov 12 06:05:17 2004
Date: Fri, 12 Nov 2004 03:05:06 -0800 (PST)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Fri, 12 Nov 2004 Volume: 10 Number: 7396
Today's topics:
\$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} <vijai.lists@gmail.com>
Re: \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){ <vijai.lists@gmail.com>
Re: \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){ <do-not-use@invalid.net>
Re: \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){ (Anno Siegel)
FAQ 8.30: How can I convert my shell script to perl? <comdog@panix.com>
Re: FAQ 9.16: How do I decode a CGI form? <do-not-use@invalid.net>
Re: FAQ 9.16: How do I decode a CGI form? <sholden@flexal.cs.usyd.edu.au>
Re: HELP: Where's the FAQ? <dha@panix.com>
Re: Legacy End of File Problems with 012 and 000 <zen13097@zen.co.uk>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
simple perl script for automatic form submission. <sam.wun@authtec.net>
Re: simple perl script for automatic form submission. <ioneabu@yahoo.com>
Re: why is pattern matching using '|' slower than 2 sep <nospam-abuse@ilyaz.org>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 12 Nov 2004 02:37:04 -0600
From: Vijayaraghavan Kalyanapasupathy <vijai.lists@gmail.com>
Subject: \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} | (\$environment\{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+"\}){1,1})\}
Message-Id: <MPG.1bfe32152de5fbfd989691@news.vanderbilt.edu>
Hi,
I am trying to write a regular expression to match the following
patterns:
\$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} | (\$environment
\{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))*"\}){1,1})\}
Here is what it is supposed to do:
In general match all patterns of the form:
$:xml-ms{ <something> }
where something is one of:
Variable:
--------
X.y.z
_x._y.z
m
but not
.Y.
.Y.Z
09.abs.d
Essentially each component of the "dotted" expression is like an
identifier matching:
[A-Za-z_]+\w*
I handle this by the regex:
(([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))*)
which matches the above types. This does work on the examples I tested.
The test cases are:
Should match: Hi $:xml-ms{_._.x}
Should match: Hi $:xml-ms{_09._87.x}
Should match: Hi $:xml-ms{_09.abc.y}
Should not match: Hi $:xml-ms{_09.87.x}
Should not match: Hi $:xml-ms{_09._87.}
Should not match: Hi $:xml-ms{abs.87.x}
Should not match: Hi $:xml-ms{._a8d7c.x}
Should not match: Hi $:xml-ms{a.._}
The above works fine and as expected.
Environment variable:
--------------------
$environment{"<variable>"}
This can be expressed as:
\$environment\{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))*"\}
Which should match
$environment{"x.y.z"}
and so on just as above but with the surrounding extras!
When I combine the two regular expressions with the choice |
it doesn't work even though the input I tried is the same as above.
Any suggestions,
thanx,
-vijai.
------------------------------
Date: Fri, 12 Nov 2004 02:38:22 -0600
From: Vijayaraghavan Kalyanapasupathy <vijai.lists@gmail.com>
Subject: Re: \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} | (\$environment\{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+"\}){1,1})\}
Message-Id: <MPG.1bfe327bc64fde41989692@news.vanderbilt.edu>
In article <MPG.1bfe32152de5fbfd989691@news.vanderbilt.edu>,
vijai.lists@gmail.com says...
> In general match all patterns of the form:
>
> $:xml-ms{ <something> }
>
> where something is one of:
Well, I meant <something>
Apologies,
-vijai.
------------------------------
Date: 12 Nov 2004 10:36:46 +0100
From: Arndt Jonasson <do-not-use@invalid.net>
Subject: Re: \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} | (\$environment\{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+"\}){1,1})\}
Message-Id: <yzd654be7dd.fsf@invalid.net>
Vijayaraghavan Kalyanapasupathy <vijai.lists@gmail.com> writes:
>
> I am trying to write a regular expression to match the following
> patterns:
>
> \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} | (\$environment
> \{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))*"\}){1,1})\}
("Regular expression to match a pattern" sounds a little wrong to me.
I would usually use either "regular expression to match a string", or
"pattern to match a string". But I might also use "pattern" more
generically in simply describing the string.)
From your description, it appears to me that you want the expression
to match one of two things, and you use '|' to separate the two
things in the expression.
In the above expression, you have spaces around the '|' character.
That means that spaces have to be present in the string in order for
the expression to match.
Simple example: /abc | def/ matches "abc " and it matches " def", but
not "abc" or "def". /abc|def/ does match both "abc" and "def".
So maybe the solution is to remove those spaces.
------------------------------
Date: 12 Nov 2004 10:47:05 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} | (\$environment\{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+"\}){1,1})\}
Message-Id: <cn24b9$m71$1@mamenchi.zrz.TU-Berlin.DE>
Vijayaraghavan Kalyanapasupathy <vijai.lists@gmail.com> wrote in comp.lang.perl.misc:
> Hi,
>
> I am trying to write a regular expression to match the following
> patterns:
>
> \$:xml-ms\{((([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))+){1,1} | (\$environment
> \{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))*"\}){1,1})\}
Ugh. That regex is much too big to be comprehensible, not to mention
maintainable. That also makes it a poor choice for a subject line.
> Here is what it is supposed to do:
>
> In general match all patterns of the form:
>
> $:xml-ms{ <something> }
>
> where something is one of:
>
> Variable:
> --------
>
> X.y.z
> _x._y.z
> m
>
> but not
>
> .Y.
> .Y.Z
> 09.abs.d
>
> Essentially each component of the "dotted" expression is like an
> identifier matching:
>
> [A-Za-z_]+\w*
>
> I handle this by the regex:
>
> (([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))*)
>
> which matches the above types. This does work on the examples I tested.
>
> The test cases are:
>
> Should match: Hi $:xml-ms{_._.x}
> Should match: Hi $:xml-ms{_09._87.x}
> Should match: Hi $:xml-ms{_09.abc.y}
>
> Should not match: Hi $:xml-ms{_09.87.x}
> Should not match: Hi $:xml-ms{_09._87.}
> Should not match: Hi $:xml-ms{abs.87.x}
> Should not match: Hi $:xml-ms{._a8d7c.x}
> Should not match: Hi $:xml-ms{a.._}
>
> The above works fine and as expected.
>
> Environment variable:
> --------------------
>
> $environment{"<variable>"}
>
> This can be expressed as:
>
> \$environment\{"([a-zA-Z_]+\w*)+(\.([a-zA-Z_]+\w*))*"\}
>
> Which should match
>
> $environment{"x.y.z"}
>
> and so on just as above but with the surrounding extras!
>
> When I combine the two regular expressions with the choice |
> it doesn't work even though the input I tried is the same as above.
>
> Any suggestions,
You ought to split up the problem some more and not try to do everything
in a single regex.
So you have two cases that wrap the same structure (called <something>
above) in slightly different ways. Treat them separately:
my $something;
my $ok = ( ( $something) = /\$:xml-ms{\s*(\S+)\s*}/ ) ||
( ( $something) = /\$environment{"\s*(\S+)\s*"}/);
If $ok is false at this point, that is the answer and there is nothing
more to do. Otherwise, we had a match, and the $something part is filled.
To check if it is a sequence of identifiers with dots between them,
split it on dots and check each component:
$ok &&= /^[a-zA-Z_]\w*$/ for split /\./, $something, -1;
Now $ok is your answer.
It takes four lines instead of two (and two auxiliary variables), but
it is far more readable and adaptable. It also makes use of the fact
that $something has the same structure in both cases, instead of
repeating the code as the regex does.
Anno
------------------------------
Date: Fri, 12 Nov 2004 11:03:00 +0000 (UTC)
From: PerlFAQ Server <comdog@panix.com>
Subject: FAQ 8.30: How can I convert my shell script to perl?
Message-Id: <cn2594$9pf$1@reader1.panix.com>
This message is one of several periodic postings to comp.lang.perl.misc
intended to make it easier for perl programmers to find answers to
common questions. The core of this message represents an excerpt
from the documentation provided with Perl.
--------------------------------------------------------------------
8.30: How can I convert my shell script to perl?
Learn Perl and rewrite it. Seriously, there's no simple converter.
Things that are awkward to do in the shell are easy to do in Perl, and
this very awkwardness is what would make a shell->perl converter nigh-on
impossible to write. By rewriting it, you'll think about what you're
really trying to do, and hopefully will escape the shell's pipeline
datastream paradigm, which while convenient for some matters, causes
many inefficiencies.
--------------------------------------------------------------------
Documents such as this have been called "Answers to Frequently
Asked Questions" or FAQ for short. They represent an important
part of the Usenet tradition. They serve to reduce the volume of
redundant traffic on a news group by providing quality answers to
questions that keep coming up.
If you are some how irritated by seeing these postings you are free
to ignore them or add the sender to your killfile. If you find
errors or other problems with these postings please send corrections
or comments to the posting email address or to the maintainers as
directed in the perlfaq manual page.
Note that the FAQ text posted by this server may have been modified
from that distributed in the stable Perl release. It may have been
edited to reflect the additions, changes and corrections provided
by respondents, reviewers, and critics to previous postings of
these FAQ. Complete text of these FAQ are available on request.
The perlfaq manual page contains the following copyright notice.
AUTHOR AND COPYRIGHT
Copyright (c) 1997-2002 Tom Christiansen and Nathan
Torkington, and other contributors as noted. All rights
reserved.
This posting is provided in the hope that it will be useful but
does not represent a commitment or contract of any kind on the part
of the contributers, authors or their agents.
------------------------------
Date: 12 Nov 2004 10:04:03 +0100
From: Arndt Jonasson <do-not-use@invalid.net>
Subject: Re: FAQ 9.16: How do I decode a CGI form?
Message-Id: <yzdactne8vw.fsf@invalid.net>
Uri Guttman <uri@stemsystems.com> writes:
> >>>>> "BM" == Brian McCauley <nobull@mail.com> writes:
>
> BM> I concur with Gunnar about this rant adversely affecting
> BM> credibility. (Personal winge: I don't like the use of the word
> BM> 'unprofessional'. A professional is, by definition, someone getting
> BM> paid to work on something. The implication of using 'unprofessional'
> BM> in this way that work for which people is paid is necessaritly of a
> BM> higher quality than work that is given freely is anathma to me).
>
> i disagree with your definition of professional. in my high school drama
> class our teacher said that there were professional (paid) productions
> that were amateurish and amatuer productions that were professional. i
> know many open source coders who i would call professional even without
> getting paid and we have all seen paid cow-orkers that shouldn't be in
> the coding profession.
>
> so doing something like coding a cgi parser by yourself (or cargo
> culting one) is unprofessional whether you get paid or not.
>
> very recently i saw some automatically generated form handling scripts
> (the site claims it can generate in multiple web langs. i bet equally
> badly). it had a classic cargo culted buggy cgi parser and perl4 style
This phrase "cargo cult" is something I hadn't seen before I started
reading this news group. I think it's a very good expression (I think
I know what it means in real life, but I'll refrain from trying to
explain it), but where did it originate in the context of programming?
It can certainly be applied to other languages than Perl.
As for the meanings of "professional", "unprofessional" in this
context seems only seldom to be used in the sense of "done for no
monetary gain", and more often used in the sense of "without respect
for or knowledge of established good practice". Other than that, I
agree with BM's anathema statement.
------------------------------
Date: 12 Nov 2004 09:57:29 GMT
From: Sam Holden <sholden@flexal.cs.usyd.edu.au>
Subject: Re: FAQ 9.16: How do I decode a CGI form?
Message-Id: <slrncp9289.qnp.sholden@flexal.cs.usyd.edu.au>
On 12 Nov 2004 10:04:03 +0100, Arndt Jonasson <do-not-use@invalid.net> wrote:
>
>
> This phrase "cargo cult" is something I hadn't seen before I started
> reading this news group. I think it's a very good expression (I think
> I know what it means in real life, but I'll refrain from trying to
> explain it), but where did it originate in the context of programming?
> It can certainly be applied to other languages than Perl.
It's a term that isn't restricted to perl, I've heard it used with
other languages. Perl suffers from it greatly due to Perl's
popularity in early (and later) CGI programming. Hence lots of bad
code was written by those not exactly "skilled in the art" and
since it was for the web, it was published on the web and then
copied by others even less skilled in the art...
http://www.catb.org/~esr/jargon/html/C/cargo-cult-programming.html
Claims that in the context of programming the term probably came via
physics rather than directly from the cargo cult airport rituals of
some post WWII South Pacific islands.
Though the oroginal term has more in common with the programming
version than the science one, in my opinion anyway...
--
Sam Holden
------------------------------
Date: Fri, 12 Nov 2004 08:18:05 +0000 (UTC)
From: "David H. Adler" <dha@panix.com>
Subject: Re: HELP: Where's the FAQ?
Message-Id: <slrncp8sdt.rtr.dha@panix2.panix.com>
On 2004-11-12, ft4bredn <none@anytime.net> wrote:
> Is the FAQ regularly posted? How can I get it?
If you mean the Perl FAQ, not only is it posted here frequently (as
others have pointed out), but it's in the perl documentation of any
computer with a well installed perl distribution.
If, however, you mean a FAQ for clpmisc, there isn't one as such. There
are Posting Guidelines which are posted in the group regularly.
dha
--
David H. Adler - <dha@panix.com> - http://www.panix.com/~dha/
Sturgeon's Law: 90% of everything is crap.
Cassell's Corollary: Sturgeon would have upped that number if he'd
seen the Internet.
------------------------------
Date: 12 Nov 2004 08:48:27 GMT
From: Dave Weaver <zen13097@zen.co.uk>
Subject: Re: Legacy End of File Problems with 012 and 000
Message-Id: <419478db$0$27538$db0fefd9@news.zen.co.uk>
On 10 Nov 2004 19:32:21 -0800, Greg Ennis <PoMec@PoMec.Net> wrote:
> Thanks much for your help. I still have not been able to make it work
> like I need, but I need to read more about your suggestions. Thanks
> again for the help!!!
Open the file for read/write (perldoc -f open).
Use seek() to position the "write pointer" over the 000 byte that you
want to overwrite (perldoc -f seek).
Write out the data you want to append (perldoc -f print).
Job done.
Something like this:
$ perl -e 'print "hello world\012\000"' > file
$ xxd file
0000000: 6865 6c6c 6f20 776f 726c 640a 00 hello world..
$ cat append
#!/usr/bin/perl
use strict;
use warnings;
use Fcntl ":seek";
my $file = "/tmp/file";
open my $f, "+< $file" or die "Can't open '$file' : $!";
seek $f, -1, SEEK_END or die "seek failed : $!";
print $f "more\012\000";
close $f;
$ perl append
$ xxd file
0000000: 6865 6c6c 6f20 776f 726c 640a 6d6f 7265 hello world.more
0000010: 0a00 ..
$
Was that what you wanted to do?
--
Dave
------------------------------
Date: 12 Nov 2004 08:23:37 GMT
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.5 $)
Message-Id: <41947308$0$28454$8b463f8a@news.nationwide.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.5 $)
This newsgroup, commonly called clpmisc, is a technical newsgroup
intended to be used for discussion of Perl related issues (except job
postings), whether it be comments or questions.
As you would expect, clpmisc discussions are usually very technical in
nature and there are conventions for conduct in technical newsgroups
going somewhat beyond those in non-technical newsgroups.
The article at:
http://www.catb.org/~esr/faqs/smart-questions.html
describes how to get answers from technical people in general.
This article describes things that you should, and should not, do to
increase your chances of getting an answer to your Perl question. It is
available in POD, HTML and plain text formats at:
http://mail.augustmail.com/~tadmc/clpmisc.shtml
For more information about netiquette in general, see the "Netiquette
Guidelines" at:
http://andrew2.andrew.cmu.edu/rfc/rfc1855.html
A note to newsgroup "regulars":
Do not use these guidelines as a "license to flame" or other
meanness. It is possible that a poster is unaware of things
discussed here. Give them the benefit of the doubt, and just
help them learn how to post, rather than assume
A note about technical terms used here:
In this document, we use words like "must" and "should" as
they're used in technical conversation (such as you will
encounter in this newsgroup). When we say that you *must* do
something, we mean that if you don't do that something, then
it's unlikely that you will benefit much from this group.
We're not bossing you around; we're making the point without
lots of words.
Do *NOT* send email to the maintainer of these guidelines. It will be
discarded unread. The guidelines belong to the newsgroup so all
discussion should appear in the newsgroup. I am just the secretary that
writes down the consensus of the group.
Before posting to comp.lang.perl.misc
Must
This section describes things that you *must* do before posting to
clpmisc, in order to maximize your chances of getting meaningful replies
to your inquiry and to avoid getting flamed for being lazy and trying to
have others do your work.
The perl distribution includes documentation that is copied to your hard
drive when you install perl. Also installed is a program for looking
things up in that (and other) documentation named 'perldoc'.
You should either find out where the docs got installed on your system,
or use perldoc to find them for you. Type "perldoc perldoc" to learn how
to use perldoc itself. Type "perldoc perl" to start reading Perl's
standard documentation.
Check the Perl Frequently Asked Questions (FAQ)
Checking the FAQ before posting is required in Big 8 newsgroups in
general, there is nothing clpmisc-specific about this requirement.
You are expected to do this in nearly all newsgroups.
You can use the "-q" switch with perldoc to do a word search of the
questions in the Perl FAQs.
Check the other standard Perl docs (*.pod)
The perl distribution comes with much more documentation than is
available for most other newsgroups, so in clpmisc you should also
see if you can find an answer in the other (non-FAQ) standard docs
before posting.
It is *not* required, or even expected, that you actually *read* all of
Perl's standard docs, only that you spend a few minutes searching them
before posting.
Try doing a word-search in the standard docs for some words/phrases
taken from your problem statement or from your very carefully worded
"Subject:" header.
Really Really Should
This section describes things that you *really should* do before posting
to clpmisc.
Lurk for a while before posting
This is very important and expected in all newsgroups. Lurking means
to monitor a newsgroup for a period to become familiar with local
customs. Each newsgroup has specific customs and rituals. Knowing
these before you participate will help avoid embarrassing social
situations. Consider yourself to be a foreigner at first!
Search a Usenet archive
There are tens of thousands of Perl programmers. It is very likely
that your question has already been asked (and answered). See if you
can find where it has already been answered.
One such searchable archive is:
http://groups.google.com/advanced_group_search
If You Like
This section describes things that you *can* do before posting to
clpmisc.
Check Other Resources
You may want to check in books or on web sites to see if you can
find the answer to your question.
But you need to consider the source of such information: there are a
lot of very poor Perl books and web sites, and several good ones
too, of course.
Posting to comp.lang.perl.misc
There can be 200 messages in clpmisc in a single day. Nobody is going to
read every article. They must decide somehow which articles they are
going to read, and which they will skip.
Your post is in competition with 199 other posts. You need to "win"
before a person who can help you will even read your question.
These sections describe how you can help keep your article from being
one of the "skipped" ones.
Is there a better place to ask your question?
Question should be about Perl, not about the application area
It can be difficult to separate out where your problem really is,
but you should make a conscious effort to post to the most
applicable newsgroup. That is, after all, where you are the most
likely to find the people who know how to answer your question.
Being able to "partition" a problem is an essential skill for
effectively troubleshooting programming problems. If you don't get
that right, you end up looking for answers in the wrong places.
It should be understood that you may not know that the root of your
problem is not Perl-related (the two most frequent ones are CGI and
Operating System related), so off-topic postings will happen from
time to time. Be gracious when someone helps you find a better place
to ask your question by pointing you to a more applicable newsgroup.
How to participate (post) in the clpmisc community
Carefully choose the contents of your Subject header
You have 40 precious characters of Subject to win out and be one of
the posts that gets read. Don't waste them. Take care while
composing them, they are the key that opens the door to getting an
answer.
Spend them indicating what aspect of Perl others will find if they
should decide to read your article.
Do not spend them indicating "experience level" (guru, newbie...).
Do not spend them pleading (please read, urgent, help!...).
Do not spend them on non-Subjects (Perl question, one-word
Subject...)
For more information on choosing a Subject see "Choosing Good
Subject Lines":
http://www.cpan.org/authors/id/D/DM/DMR/subjects.post
Part of the beauty of newsgroup dynamics, is that you can contribute
to the community with your very first post! If your choice of
Subject leads a fellow Perler to find the thread you are starting,
then even asking a question helps us all.
Use an effective followup style
When composing a followup, quote only enough text to establish the
context for the comments that you will add. Always indicate who
wrote the quoted material. Never quote an entire article. Never
quote a .signature (unless that is what you are commenting on).
Intersperse your comments *following* each section of quoted text to
which they relate. Unappreciated followup styles are referred to as
"top-posting", "Jeopardy" (because the answer comes before the
question), or "TOFU" (Text Over, Fullquote Under).
Reversing the chronology of the dialog makes it much harder to
understand (some folks won't even read it if written in that style).
For more information on quoting style, see:
http://web.presby.edu/~nnqadmin/nnq/nquote.html
Speak Perl rather than English, when possible
Perl is much more precise than natural language. Saying it in Perl
instead will avoid misunderstanding your question or problem.
Do not say: I have variable with "foo\tbar" in it.
Instead say: I have $var = "foo\tbar", or I have $var = 'foo\tbar',
or I have $var = <DATA> (and show the data line).
Ask perl to help you
You can ask perl itself to help you find common programming mistakes
by doing two things: enable warnings (perldoc warnings) and enable
"strict"ures (perldoc strict).
You should not bother the hundreds/thousands of readers of the
newsgroup without first seeing if a machine can help you find your
problem. It is demeaning to be asked to do the work of a machine. It
will annoy the readers of your article.
You can look up any of the messages that perl might issue to find
out what the message means and how to resolve the potential mistake
(perldoc perldiag). If you would like perl to look them up for you,
you can put "use diagnostics;" near the top of your program.
Do not re-type Perl code
Use copy/paste or your editor's "import" function rather than
attempting to type in your code. If you make a typo you will get
followups about your typos instead of about the question you are
trying to get answered.
Provide enough information
If you do the things in this item, you will have an Extremely Good
chance of getting people to try and help you with your problem!
These features are a really big bonus toward your question winning
out over all of the other posts that you are competing with.
First make a short (less than 20-30 lines) and *complete* program
that illustrates the problem you are having. People should be able
to run your program by copy/pasting the code from your article. (You
will find that doing this step very often reveals your problem
directly. Leading to an answer much more quickly and reliably than
posting to Usenet.)
Describe *precisely* the input to your program. Also provide example
input data for your program. If you need to show file input, use the
__DATA__ token (perldata.pod) to provide the file contents inside of
your Perl program.
Show the output (including the verbatim text of any messages) of
your program.
Describe how you want the output to be different from what you are
getting.
If you have no idea at all of how to code up your situation, be sure
to at least describe the 2 things that you *do* know: input and
desired output.
Do not provide too much information
Do not just post your entire program for debugging. Most especially
do not post someone *else's* entire program.
Do not post binaries, HTML, or MIME
clpmisc is a text only newsgroup. If you have images or binaries
that explain your question, put them in a publically accessible
place (like a Web server) and provide a pointer to that location. If
you include code, cut and paste it directly in the message body.
Don't attach anything to the message. Don't post vcards or HTML.
Many people (and even some Usenet servers) will automatically filter
out such messages. Many people will not be able to easily read your
post. Plain text is something everyone can read.
Social faux pas to avoid
The first two below are symptoms of lots of FAQ asking here in clpmisc.
It happens so often that folks will assume that it is happening yet
again. If you have looked but not found, or found but didn't understand
the docs, say so in your article.
Asking a Frequently Asked Question
It should be understood that you may have missed the applicable FAQ
when you checked, which is not a big deal. But if the Frequently
Asked Question is worded similar to your question, folks will assume
that you did not look at all. Don't become indignant at pointers to
the FAQ, particularly if it solves your problem.
Asking a question easily answered by a cursory doc search
If folks think you have not even tried the obvious step of reading
the docs applicable to your problem, they are likely to become
annoyed.
If you are flamed for not checking when you *did* check, then just
shrug it off (and take the answer that you got).
Asking for emailed answers
Emailed answers benefit one person. Posted answers benefit the
entire community. If folks can take the time to answer your
question, then you can take the time to go get the answer in the
same place where you asked the question.
It is OK to ask for a *copy* of the answer to be emailed, but many
will ignore such requests anyway. If you munge your address, you
should never expect (or ask) to get email in response to a Usenet
post.
Ask the question here, get the answer here (maybe).
Beware of saying "doesn't work"
This is a "red flag" phrase. If you find yourself writing that,
pause and see if you can't describe what is not working without
saying "doesn't work". That is, describe how it is not what you
want.
Sending a "stealth" Cc copy
A "stealth Cc" is when you both email and post a reply without
indicating *in the body* that you are doing so.
Be extra cautious when you get upset
Count to ten before composing a followup when you are upset
This is recommended in all Usenet newsgroups. Here in clpmisc, most
flaming sub-threads are not about any feature of Perl at all! They
are most often for what was seen as a breach of netiquette. If you
have lurked for a bit, then you will know what is expected and won't
make such posts in the first place.
But if you get upset, wait a while before writing your followup. I
recommend waiting at least 30 minutes.
Count to ten after composing and before posting when you are upset
After you have written your followup, wait *another* 30 minutes
before committing yourself by posting it. You cannot take it back
once it has been said.
AUTHOR
Tad McClellan <tadmc@augustmail.com> and many others on the
comp.lang.perl.misc newsgroup.
------------------------------
Date: Fri, 12 Nov 2004 17:03:14 +0800
From: sam <sam.wun@authtec.net>
Subject: simple perl script for automatic form submission.
Message-Id: <cn1vpp$14lf$1@news.hgc.com.hk>
Hi,
I m not a perl expert.
I would like to write a simple perl script to automatically login my
email account that hosted by a commerical webmail server.
Is there any sample script I can follow?
Thanks
Sam
------------------------------
Date: Fri, 12 Nov 2004 06:59:54 -0500
From: wana <ioneabu@yahoo.com>
Subject: Re: simple perl script for automatic form submission.
Message-Id: <10p963ek01ekt6e@news.supernews.com>
sam wrote:
> Hi,
>
> I m not a perl expert.
> I would like to write a simple perl script to automatically login my
> email account that hosted by a commerical webmail server.
>
> Is there any sample script I can follow?
>
> Thanks
> Sam
try LWP::UserAgent from CPAN (actually it already came with my Linux
installation).
I just started playing with it and was able to get into a site I created but
I then tried submitting data to some commercial sites and my script was
rejected with the same form data I was able to submit legitimately through
their webpage. I am not sure how to 'trick' the site into not knowing if
it is a web browser or a Perl script trying to submit form data. I can get
as far as looking at the html source, finding the form, identifying POST or
GET, and finding the field names.
Since I was able to log into my own homemade site, I know it works and is
not a Perl issue. 'Perl Cookbook' has a brief section on LWP and there is
probably more in Lincoln Stein's book on Perl networking.
wana
------------------------------
Date: Fri, 12 Nov 2004 10:32:47 +0000 (UTC)
From: Ilya Zakharevich <nospam-abuse@ilyaz.org>
Subject: Re: why is pattern matching using '|' slower than 2 separate ones?
Message-Id: <cn23gf$2q77$1@agate.berkeley.edu>
[A complimentary Cc of this posting was sent to
<ctcgag@hotmail.com>], who wrote in article <20041111181240.368$ui@newsreader.com>:
> > This has little relation to what actually happens.
Wishfull thinking...
> It looks like the optimizer is not doing the rejections on the first
> version, it is only doing rejections on the 2nd versions.
Right, it should do something similar to
>perl -Mre=debugcolor -wle "$z = 'ZZZZZZZZZ'; $z=~/x*[y]/;"
Compiling REx `x*[y]'
size 15 Got 124 bytes for offset annotations.
first at 1
synthetic stclass `ANYOF[xy]'.
1: STAR(4)
2: EXACT <x>(0)
4: ANYOF[y](15)
15: END(0)
stclass `ANYOF[xy]' minlen 1
Offsets: [15]
2[1] 1[1] 0[0] 3[3] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0]
0[0] 0[0] 6
Matching REx `x*[y]' against `ZZZZZZZZZ'
Matching stclass `ANYOF[xy]' against `ZZZZZZZZZ'
Contradicts stclass...
Match failed
Note the "synthetic stclass"; it should be the same for x|y; but it is
not. A bug in optimizer...
Thanks for bringing it to my attention, but better report it to p5p too,
Ilya
------------------------------
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 7396
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