[23777] in Perl-Users-Digest
Perl-Users Digest, Issue: 5981 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Dec 26 06:05:48 2003
Date: Fri, 26 Dec 2003 03:05:05 -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, 26 Dec 2003 Volume: 10 Number: 5981
Today's topics:
Binary program? <goth1938@hotmail.com>
CGI: Calling C is different? (Huey)
Re: CGI: Calling C is different? (Tad McClellan)
Re: CGI: Calling C is different? (Charles DeRykus)
invalid top directory <spamme@hotmail.com>
Re: invalid top directory <noreply@gunnar.cc>
Re: invalid top directory <spamme@hotmail.com>
isql in perl (mike)
Re: isql in perl <nospam@bigpond.com>
matching balanced parens (ivo welch)
Re: matching balanced parens <noreply@gunnar.cc>
Passing variable to Perl Gimp script via command line <frederik_betterremovethis@vanrenterghem.biz>
Re: Please critique this short script that scans a log <troc@pobox.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Re: why this code shots up memory usage <a_madhur@vsnl.net>
Win32::ODBC problem <arthur0421@163.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 26 Dec 2003 15:18:51 +0800
From: "Just in" <goth1938@hotmail.com>
Subject: Binary program?
Message-Id: <bsgnct$fd4$1@news01.intel.com>
Theres this old Apollo Unix station that runs a cronjob that actually does
something, that I'm supposed to help identify.
What the cronjob calls is what I assume to be a Perl program, because the
first line has the path perl on it with old shebang hash in front of it.
What miffs me is what follows after it - binary characters without any EOL
termination.
I assume this is encrypted, or even compiled. But I'm not so sure how perl
is interpreting the binary.
I know it would help if I posted an example, but I can't as it is
confidential information to my company.
Any thoughts as to what it might be would be appreciated.
Bests Just in
------------------------------
Date: 25 Dec 2003 21:01:27 -0800
From: huey_jiang@yahoo.com (Huey)
Subject: CGI: Calling C is different?
Message-Id: <ae92bb50.0312252101.41d323d@posting.google.com>
Hi All,
I wonder that is there any difference of calling C executable in CGI
from the "normal"? A few days ago, with helps from Tad, Jim,
Christian, I did make my perl scripts got returns from C executables.
Thanks go to Jim, Christian, and Tad! However, when I put my code into
CGI, broken! I can't figure out the kicker, thus here for help. My
code test.pl:
#!/usr/bin/perl
print "Content-type: text/html", "\n\n\n";
my $mytest = "./c_hello.exe";
open TEST, "$mytest |" or die "Error running $mytest: $!\n";
while(<TEST>) {
print "The return from C is: $_", "\n";
}
close (TEST);
exit (0);
This piece of code works in command-line: %perl test.pl, and prints
out "Hi All". But, it does not work as a CGI script with a html file.
Anybody helps me out? Thanks a lot, and wish you have a happy NEW
YEAR!
Huey
------------------------------
Date: Fri, 26 Dec 2003 00:22:44 -0600
From: tadmc@augustmail.com (Tad McClellan)
Subject: Re: CGI: Calling C is different?
Message-Id: <slrnbunktk.bq5.tadmc@magna.augustmail.com>
Huey <huey_jiang@yahoo.com> wrote:
> I wonder that is there any difference of calling C executable in CGI
> from the "normal"?
No.
And there is no such thing as a "C executable".
Once it is compiled to an executable, it is an executable, regardless
of what language it was originally written in.
> when I put my code into
> CGI, broken!
I wonder what "broken" means when you say it.
What does "broken" mean when you say it?
A white screen?
A black screen?
A screenful of gobbledy gook?
Messages in your server log?
Too much output?
Too little output?
The wrong output?
Smoke comes out of the computer's vents?
> it does not work as a CGI script
I wonder what "does not work" means when you say it.
> Anybody helps me out?
It is much easier to make a diagnosis if we have one or more symptoms.
Have you seen the Posting Guidelines that are posted here frequently?
WAG:
use an absolute path instead of a relative path to the exe
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
Date: Fri, 26 Dec 2003 07:04:41 GMT
From: ced@bcstec.ca.boeing.com (Charles DeRykus)
Subject: Re: CGI: Calling C is different?
Message-Id: <HqHqBt.L5y@news.boeing.com>
In article <ae92bb50.0312252101.41d323d@posting.google.com>,
Huey <huey_jiang@yahoo.com> wrote:
>Hi All,
>
>I wonder that is there any difference of calling C executable in CGI
>from the "normal"? A few days ago, with helps from Tad, Jim,
>Christian, I did make my perl scripts got returns from C executables.
>Thanks go to Jim, Christian, and Tad! However, when I put my code into
>CGI, broken! I can't figure out the kicker, thus here for help. My
>code test.pl:
>
>#!/usr/bin/perl
>print "Content-type: text/html", "\n\n\n";
>
>my $mytest = "./c_hello.exe";
>open TEST, "$mytest |" or die "Error running $mytest: $!\n";
>while(<TEST>) {
> print "The return from C is: $_", "\n";
>}
>close (TEST);
>exit (0);
>
>This piece of code works in command-line: %perl test.pl, and prints
>out "Hi All". But, it does not work as a CGI script with a html file.
>Anybody helps me out? Thanks a lot, and wish you have a happy NEW
>YEAR!
>
I could guess but you'd probably be better off doing a little research
on your own. Start with 'perldoc -q cgi' for some relevant tidbits and
faq's.
One good idea, whether the setting is CGI or not, is to set warnings
and strictures. Additionally, redirecting stderr to the screen can
be very useful during CGI development.
use CGI::Carp (fatalsToBrowser warningsToBrowser);
hth,
--
Charles DeRykus
------------------------------
Date: Thu, 25 Dec 2003 23:15:38 GMT
From: "SRB" <spamme@hotmail.com>
Subject: invalid top directory
Message-Id: <ucKGb.179310$%TO.163369@twister01.bloor.is.net.cable.rogers.com>
I get invalid top directory at E:/Perl/lib/File/Find.pm line 562. when i
run this in windows. Can someone explain what I am doing wrong?
use File::Find;
use Win32::File;
use Win32API::File 0.08 qw( :ALL );
my $LogDir = "C:\\";
print $LogDir;
&File::Find::find(\&doFile, $Logdir);
print "done.\n";
sub doFile
{
return unless (-f $_);
print "File: $_ \n";
}
------------------------------
Date: Fri, 26 Dec 2003 01:04:16 +0100
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: invalid top directory
Message-Id: <bsftr5$cnmbq$1@ID-184292.news.uni-berlin.de>
SRB wrote:
> I get invalid top directory at E:/Perl/lib/File/Find.pm line 562.
> when i run this in windows. Can someone explain what I am doing
> wrong?
You run your script without having strictures enabled. That's very
wrong. Do not ask for help here without having asked Perl first! ;-)
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: Fri, 26 Dec 2003 01:23:32 GMT
From: "SRB" <spamme@hotmail.com>
Subject: Re: invalid top directory
Message-Id: <o4MGb.162419$ea%.121307@news01.bloor.is.net.cable.rogers.com>
"Gunnar Hjalmarsson" <noreply@gunnar.cc> wrote in message
news:bsftr5$cnmbq$1@ID-184292.news.uni-berlin.de...
> SRB wrote:
> > I get invalid top directory at E:/Perl/lib/File/Find.pm line 562.
> > when i run this in windows. Can someone explain what I am doing
> > wrong?
>
> You run your script without having strictures enabled. That's very
> wrong. Do not ask for help here without having asked Perl first! ;-)
>
Thanks. My girlfriend is always complaining about my case insensitivity.
------------------------------
Date: 25 Dec 2003 23:43:21 -0800
From: s99999999s2003@yahoo.com (mike)
Subject: isql in perl
Message-Id: <dfd17ef4.0312252343.1b251cbd@posting.google.com>
hi
i have a code like this
open ISQL, "| isql -U $user -S $server " or die "Failed to open: $!";
print ISQL << "EOF";
select count(*) from table
go
quit
EOF
this code is suppose to get the count from a table in my database.
how can i assign this count to a perl variable??
thanks...
------------------------------
Date: Fri, 26 Dec 2003 18:17:55 +1000
From: Gregory Toomey <nospam@bigpond.com>
Subject: Re: isql in perl
Message-Id: <1080562.d8XGKOZNtQ@gregs-web-hosting-and-pickle-farming>
It was a dark and stormy night, and mike managed to scribble:
> hi
>
> i have a code like this
>
> open ISQL, "| isql -U $user -S $server " or die "Failed to open: $!";
> print ISQL << "EOF";
> select count(*) from table
> go
> quit
> EOF
>
> this code is suppose to get the count from a table in my database.
> how can i assign this count to a perl variable??
> thanks...
Use Perl dbi instead http://dbi.perl.org/
gtoomey
------------------------------
Date: 25 Dec 2003 19:51:30 -0800
From: ivo.welch@anderson.ucla.edu (ivo welch)
Subject: matching balanced parens
Message-Id: <5159bba2.0312251951.4331869f@posting.google.com>
I have tried for a while to figure out how to use the experimental
perl regex balanced paren feature (perlfaq6), but failed. if this is
possible, could someone please give me an example of the magic
invokation?
$text= "this is \macro{a { irrelevant } b} and this is \macro{c
{e{}}{} d}"
$text=~ s/\macro{ [matching .* to closing] }/\macro{***}/g; # help
here
and I would get
$text eq "this is \macro{***} and this is \macro{***}"
Is this even possible with regex? If not, could someone please point
me to the recommended method for global balanced substitutions (not
just matching)?
help appreciated. /iaw
------------------------------
Date: Fri, 26 Dec 2003 06:18:24 +0100
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: matching balanced parens
Message-Id: <bsggah$cr29t$1@ID-184292.news.uni-berlin.de>
ivo welch wrote:
> I have tried for a while to figure out how to use the experimental
> perl regex balanced paren feature (perlfaq6), but failed. if this
> is possible, could someone please give me an example of the magic
> invokation?
>
> $text= "this is \macro{a { irrelevant } b} and this is \macro{c
> {e{}}{} d}"
----^^
Don't know how to handle that third level of brackets, so I skipped it
in the example below.
> $text=~ s/\macro{ [matching .* to closing] }/\macro{***}/g; # help
> here
> and I would get
> $text eq "this is \macro{***} and this is \macro{***}"
The (??{ code }) example in perlre applied to two levels of brackets:
my $text = 'this is \macro{a { irrelevant } b}'
.' and this is \macro{c {e}{} d}';
my $re = qr(
{
(?:
(?> [^{}]+ )
|
(??{ $re })
)*
}
)x;
$text =~ s/(\\macro)$re/$1\{***}/g;
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: Thu, 25 Dec 2003 22:40:46 +0100
From: Frederik Vanrenterghem <frederik_betterremovethis@vanrenterghem.biz>
Subject: Passing variable to Perl Gimp script via command line
Message-Id: <pan.2003.12.25.21.40.45.461830@vanrenterghem.biz>
The script below creates a quarter of a circle. I'd like to invoke it from
the shell command line, passing a value for $circle_color
Example: ./create_quarter_circle_ul.pl 0 136 0 -o /tmp/test.png
The problem is: I don't know how to change the hardcoded value for
$circle_color. I tried using @ARGV like this:
my @circle_color = (@ARGV[0],@ARGV[1],@ARGV[2]);
gimp_palette_set_background(\@circle_color);
but I'm getting following error messages:
Use of uninitialized value in array dereference at
/usr/share/perl5/Gimp/Fu.pm line 217. Use of uninitialized value in
numeric eq (==) at /usr/share/perl5/Gimp/Fu.pm line 218.
Any ideas? If yes, please CC me on the reply. Here's the full script:
#!/usr/bin/perl
-w
use Gimp qw( :auto );
use Gimp::Fu;
sub website_quarter_circle_ul {
my $width=16;
my $height=$width;
my ($image,$layer);
my $circle_color = [0,136,0];
my $webpage_color = [255,255,255];
gimp_palette_set_background($circle_color);
$image = gimp_image_new($width, $height, RGB); $layer =
gimp_layer_new($image, $width, $height, RGBA_IMAGE, "Button", 100,
NORMAL_MODE);
gimp_image_add_layer($image, $layer, 0);
gimp_edit_clear($layer);
gimp_ellipse_select($image,-0*$height, -0*$width, $width*2,
$height*2, 0, 1, 0, 0.5);
gimp_bucket_fill($layer, BG_BUCKET_FILL, NORMAL_MODE, 100, 0, 0, 5,
5);
gimp_selection_invert($image);
gimp_palette_set_background($webpage_color);
gimp_bucket_fill($layer, BG_BUCKET_FILL, NORMAL_MODE, 100, 0, 0,
5, 5);
gimp_selection_none($image);
gimp_convert_indexed($image, 0, 0, 8,0,0, ""); return $image;
}
register
"website_quarter_circle_ul", # fill in name
"Create Website Toolbar upperleft corner button", # a small description
"A script to generate a quarter circle", # a help text
"Frederik Vanrenterghem", # Your name
"", # Your copyright
"2002-10-21", # Date
"<Toolbox>/Xtns/Perl-Fu/Website/CreateQuarterCircleUL", # menu path
"*", # Image types [
],
\&website_quarter_circle_ul;
exit main()
------------------------------
Date: Fri, 26 Dec 2003 02:35:59 GMT
From: Rocco Caputo <troc@pobox.com>
Subject: Re: Please critique this short script that scans a log file
Message-Id: <slrnbun7s4.eu.troc@eyrie.homenet>
On Thu, 25 Dec 2003 13:50:43 +0100, Matija Papec wrote:
> Nice, I hope I'll have time to study stem API as I first want look at POE.
Wise choice. POE's made a lot of large-scale sites happy, including one
of the largest Internet providers in the world.
I don't recommend the man pages for beginners, though. The web site is
a lot better. It includes tutorials, beginners' guides, and a large set
of sample programs in the "Cookbook". See: http://poe.perl.org/
There also are medium-sized #poe channels on efnet and irc.perl.org, if
you prefer realtime interaction.
--
Rocco Caputo - rcaputo@pobox.com - http://poe.perl.org/
------------------------------
Date: Fri, 26 Dec 2003 02:22:34 -0600
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.4 $)
Message-Id: <YZ-dnajMBc9XcnaiRVn-hA@august.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($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
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
"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: Fri, 26 Dec 2003 10:45:08 +0530
From: "Madhur" <a_madhur@vsnl.net>
Subject: Re: why this code shots up memory usage
Message-Id: <bsggrt$ajsci$1@ID-81175.news.uni-berlin.de>
Jay Tilton <tiltonj@erols.com> wrote in message
news:3feb17a4.485419583@news.erols.com...
> "Madhur" <a_madhur@vsnl.net> wrote:
>
[snip]
> The bad things about that:
>
> 1. Using global variables $i and @input instead of lexically
declaring them
> with my().
The code was part of main program rather than a procedure. Can i
use *my* in the main code?
> 2. Useless use of quotes in the print() statement. See "What's
wrong with
> always quoting ``$vars''? " in perlfaq4.
Indeed I agree, I won't never use them in future.
> 3. Perl programmers would rather write "while($i <
@input){...;$i++}" as
> "for my $i (0..$#input){...}" .
That means $i is local to the for loop. Right?
> 4. But they would rather not do even that. Using the array
elements'
> indeces to iterate across the elements' values is distinctly
anti-Perl.
> The program treats all the array's values in the same way. Why
should it
> care where each element is located in the array?
>
> 5. The worst thing about the program is the array itself.
Slurping an
> entire file into memory just to process its records
sequentially is amateur
> programming. If you're processing sequentially, then read
sequentially.
>
> To see the program distilled into something good, reread the
code given by
> John W. Krahn in this thread.
>
> while ( <MYFILE> ) {
> s/^\d+://;
> print;
> }
> close MYFILE;
>
Could you please explain me,this. what does while(<MYFILE>)
means.
One more think, this is the code from the faq:
Stringification also destroys arrays.
@lines = `command`;
print "@lines"; # WRONG - extra blanks
print @lines; # right
Does it mean that value of @lines is changed. Will the @lines
contain now 2 elements 'command' and ' '.
--
Winners dont do different things, they do things differently.
Madhur Ahuja
India
email : madhur<underscore>ahuja<at>yahoo<dot>com
------------------------------
Date: Fri, 26 Dec 2003 11:44:13 +0800
From: "Regent" <arthur0421@163.com>
Subject: Win32::ODBC problem
Message-Id: <bsgatk$148e$1@mail.cn99.com>
Hi folks
I'm basically a newbie to Perl...Plz forgive my stupidity :))
I'm getting lots of "Use of uninitialized value in array element at C:/Perl/lib/Win32/ODBC.pm line 256" error messages. Since there're a number of scripts, I don't even know which should be pasted here, though the error message "referer" (strangely) has nothing to do with ODBC, coz it's a higher level caller. Could anyone give me a clue what is the usual cause of such error msgs? Thanks for ur tolerance...
Regent
arthur0421@163.com
------------------------------
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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