[31363] in Perl-Users-Digest
Perl-Users Digest, Issue: 2615 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Sep 29 06:09:41 2009
Date: Tue, 29 Sep 2009 03:09:07 -0700 (PDT)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Tue, 29 Sep 2009 Volume: 11 Number: 2615
Today's topics:
Re: CGI and UTF-8 sln@netherlands.com
Re: CGI and UTF-8 <ben@morrow.me.uk>
Re: CGI and UTF-8 <OJZGSRPBZVCX@spammotel.com>
Re: CGI and UTF-8 <ben@morrow.me.uk>
controlling a process with perl <thegist@nospam.net>
FAQ 5.22 I still don't get locking. I just want to inc <brian@theperlreview.com>
FAQ 8.25 How can I capture STDERR from an external comm <brian@theperlreview.com>
FAQ 8.36 How do I fork a daemon process? <brian@theperlreview.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@seesig.invalid
the solution to some of the world's big problems is CPA <uri@StemSystems.com>
Re: the solution to some of the world's big problems is <kkeller-usenet@wombat.san-francisco.ca.us>
Re: the solution to some of the world's big problems is <sreservoir@gmail.com>
the solution to some of the world's big problems <robin1@cnsp.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Mon, 28 Sep 2009 13:13:17 -0700
From: sln@netherlands.com
Subject: Re: CGI and UTF-8
Message-Id: <7822c5hrghg6tsr4lalbcrue49i4ccjhiv@4ax.com>
On Mon, 28 Sep 2009 15:41:49 +0200, Helmut Richter <hhr-m@web.de> wrote:
>I have the task of describing for authors how to prepare forms by CGI scripts
>in perl, in particular, how to modify existing scripts to conform to a new
>CMS. Meanwhile the CGI-generated pages are all in code UTF-8.
>
<snip>
>This works but has the drawback that an extra step of decoding all input
>values to text strings is required when the interaction with the user of
>the form is over.
>
>I have the suspicion that I am thinking to complicated and that there is a
>simple -- and simple to explain -- method for dealing with CGI forms when the
>code used is UTF-8.
With Perl 5.10, cgi.pm version is $CGI::VERSION='3.41';
After some poking around in it, it looks as though it does all its filehandle
work in binary mode (moreso for the uploads I guess).
Without specifying the charset in cgi, my browser will display these cgi-
generated literal strings 'München' 'München') as:
München München - Western European (guessed)
München M? - UTF-8 (user forced)
where the same result as the second one if the html form is set to
charset utf-8.
If the form is coming back as 'München', which is utf-8, does that mean
you set the html charset to utf-8? I mean, it shouldn't otherwise, should it?
For OUTPUT, its better to set the charset to utf-8 then encode those strings that
are unicode (ASCII doesen't matter), or set the binmode of STDOUT to :utf8.
if you want to do everything.
$Muenchen = encode ('utf8', 'München');
$cgi->textfield(-name =>'ort', -value => $Muenchen, -size => 40)
For form INPUT, cgi.pm will auto-decode utf8, all form parameters for you
when you query them. Its the same decode you did above.
This can be set with a pragma in the use CGI statement like
use CGI qw/:standard -utf8/;
Aparently this pragma will only decode input.
From the docs:
" PRAGMAS
-utf8
This makes CGI.pm treat all parameters as UTF-8 strings.
Use this with care, as it will interfere with the processing of binary uploads.
It is better to manually select which fields are expected to return utf-8 strings
and convert them using code like this:
use Encode;
my $arg = decode utf8=>param('foo');
"
No matter how you look at it, if you need utf8 for input/output, there will be some
encode/decode going on somewhere.
You can avoid the encoding hassel by setting the binmode
of STDOUT to utf8 (then this is ok:
$cgi->textfield(-name =>'ort', -value => 'München', -size => 40),
and if you don't expect any binary upload data (input),
avoid the decode hassel by setting the -utf8 pragma for the
form input parameters.
Then set the charset to -utf8.
Good luck!
-sln
------------------------------
Date: Mon, 28 Sep 2009 23:01:37 +0100
From: Ben Morrow <ben@morrow.me.uk>
Subject: Re: CGI and UTF-8
Message-Id: <1bo7p6-mnm.ln1@osiris.mauzo.dyndns.org>
Quoth "Jochen Lehmeier" <OJZGSRPBZVCX@spammotel.com>:
> On Mon, 28 Sep 2009 15:41:49 +0200, Helmut Richter <hhr-m@web.de> wrote:
>
> > Dealing with UTF-8 requires that byte strings and texts strings are
> > meticulously kept apart.
>
> Uhm. What are byte strings, what are text strings? Perl does not use these
> words
> in the context of utf8.
Perl doesn't maintain the distinction itself (this is one of the flaws
in Perl's Unicode implementation) but it is nevertheless important to
keep in mind whether a given string is meant to be Unicode characters or
some encoding into bytes for IO. Proper use of binmode will let you make
all your strings character strings in simple situations.
> > else, STDOUT is UTF-8 (that is, binmode (STDOUT, ":utf8"); has been
> > done),
>
> This should not be done. The correct line would be
>
> binmode STDOUT,":encoding(utf8)";
>
> This activates error checking etc., while your version treats string as
> utf8 while
> not checking them at all, which could lead to bad_things[tm] (some docs
> hinted
> at segmentation faults even, though I do not know if that is true).
It makes no difference on output. What is important to avoid is feeding
invalid UTF8 to a handle with a :utf8 *input* layer: this certainly used
to cause segfaults in the past, though they may have been replaced with
fatal errors by now.
Ben
------------------------------
Date: Tue, 29 Sep 2009 00:15:01 +0200
From: "Jochen Lehmeier" <OJZGSRPBZVCX@spammotel.com>
Subject: Re: CGI and UTF-8
Message-Id: <op.u0zmrbljmk9oye@frodo>
On Tue, 29 Sep 2009 00:01:37 +0200, Ben Morrow <ben@morrow.me.uk> wrote:
> [:utf8 vs. :encoding(utf8)]
> It makes no difference on output.
:encoding(utf8) does validate on output though, or doesn't it?
------------------------------
Date: Mon, 28 Sep 2009 23:46:54 +0100
From: Ben Morrow <ben@morrow.me.uk>
Subject: Re: CGI and UTF-8
Message-Id: <uvq7p6-o0n.ln1@osiris.mauzo.dyndns.org>
Quoth "Jochen Lehmeier" <OJZGSRPBZVCX@spammotel.com>:
> On Tue, 29 Sep 2009 00:01:37 +0200, Ben Morrow <ben@morrow.me.uk> wrote:
>
> > [:utf8 vs. :encoding(utf8)]
> > It makes no difference on output.
>
> :encoding(utf8) does validate on output though, or doesn't it?
What do you mean, 'validate'? Perl strings are (logically) sequences of
Unicode characters, and any sequence of Unicode characters can be
represented in utf8. If you end up with a perl string with a corrupted
internal representation you've got bigger problems than invalid output
encoding.
Of course, perl's definition of 'utf8' is different from the Unicode
Consortium's 'UTF-8': the standard forbids representations of surrogates
and unassigned codepoints (and possibly other things I've forgotten). If
you want perl to enforce these restrictions you need to ask for it with
:encoding(UTF-8) (this appears to only be documented in perldoc Encode).
Ben
------------------------------
Date: Mon, 28 Sep 2009 21:35:02 -0400
From: TheGist <thegist@nospam.net>
Subject: controlling a process with perl
Message-Id: <h9ro7k$tt7$1@aioe.org>
You know how with a debugger like gdb you can attach and
detach from a process thus essentially locking and
halting it?
What would be the best way to do that with a process
but using perl?
------------------------------
Date: Tue, 29 Sep 2009 10:00:01 GMT
From: PerlFAQ Server <brian@theperlreview.com>
Subject: FAQ 5.22 I still don't get locking. I just want to increment the number in the file. How can I do this?
Message-Id: <BUkwm.195834$8B7.81503@newsfe20.iad>
This is an excerpt from the latest version perlfaq5.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .
--------------------------------------------------------------------
5.22: I still don't get locking. I just want to increment the number in the file. How can I do this?
Didn't anyone ever tell you web-page hit counters were useless? They
don't count number of hits, they're a waste of time, and they serve only
to stroke the writer's vanity. It's better to pick a random number;
they're more realistic.
Anyway, this is what you can do if you can't help yourself.
use Fcntl qw(:DEFAULT :flock);
sysopen(FH, "numfile", O_RDWR|O_CREAT) or die "can't open numfile: $!";
flock(FH, LOCK_EX) or die "can't flock numfile: $!";
$num = <FH> || 0;
seek(FH, 0, 0) or die "can't rewind numfile: $!";
truncate(FH, 0) or die "can't truncate numfile: $!";
(print FH $num+1, "\n") or die "can't write numfile: $!";
close FH or die "can't close numfile: $!";
Here's a much better web-page hit counter:
$hits = int( (time() - 850_000_000) / rand(1_000) );
If the count doesn't impress your friends, then the code might. :-)
--------------------------------------------------------------------
The perlfaq-workers, a group of volunteers, maintain the perlfaq. They
are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.
If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
------------------------------
Date: Tue, 29 Sep 2009 04:00:03 GMT
From: PerlFAQ Server <brian@theperlreview.com>
Subject: FAQ 8.25 How can I capture STDERR from an external command?
Message-Id: <7Dfwm.3153$Bl2.62@newsfe14.iad>
This is an excerpt from the latest version perlfaq8.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .
--------------------------------------------------------------------
8.25: How can I capture STDERR from an external command?
There are three basic ways of running external commands:
system $cmd; # using system()
$output = `$cmd`; # using backticks (``)
open (PIPE, "cmd |"); # using open()
With system(), both STDOUT and STDERR will go the same place as the
script's STDOUT and STDERR, unless the system() command redirects them.
Backticks and open() read only the STDOUT of your command.
You can also use the open3() function from IPC::Open3. Benjamin Goldberg
provides some sample code:
To capture a program's STDOUT, but discard its STDERR:
use IPC::Open3;
use File::Spec;
use Symbol qw(gensym);
open(NULL, ">", File::Spec->devnull);
my $pid = open3(gensym, \*PH, ">&NULL", "cmd");
while( <PH> ) { }
waitpid($pid, 0);
To capture a program's STDERR, but discard its STDOUT:
use IPC::Open3;
use File::Spec;
use Symbol qw(gensym);
open(NULL, ">", File::Spec->devnull);
my $pid = open3(gensym, ">&NULL", \*PH, "cmd");
while( <PH> ) { }
waitpid($pid, 0);
To capture a program's STDERR, and let its STDOUT go to our own STDERR:
use IPC::Open3;
use Symbol qw(gensym);
my $pid = open3(gensym, ">&STDERR", \*PH, "cmd");
while( <PH> ) { }
waitpid($pid, 0);
To read both a command's STDOUT and its STDERR separately, you can
redirect them to temp files, let the command run, then read the temp
files:
use IPC::Open3;
use Symbol qw(gensym);
use IO::File;
local *CATCHOUT = IO::File->new_tmpfile;
local *CATCHERR = IO::File->new_tmpfile;
my $pid = open3(gensym, ">&CATCHOUT", ">&CATCHERR", "cmd");
waitpid($pid, 0);
seek $_, 0, 0 for \*CATCHOUT, \*CATCHERR;
while( <CATCHOUT> ) {}
while( <CATCHERR> ) {}
But there's no real need for *both* to be tempfiles... the following
should work just as well, without deadlocking:
use IPC::Open3;
use Symbol qw(gensym);
use IO::File;
local *CATCHERR = IO::File->new_tmpfile;
my $pid = open3(gensym, \*CATCHOUT, ">&CATCHERR", "cmd");
while( <CATCHOUT> ) {}
waitpid($pid, 0);
seek CATCHERR, 0, 0;
while( <CATCHERR> ) {}
And it'll be faster, too, since we can begin processing the program's
stdout immediately, rather than waiting for the program to finish.
With any of these, you can change file descriptors before the call:
open(STDOUT, ">logfile");
system("ls");
or you can use Bourne shell file-descriptor redirection:
$output = `$cmd 2>some_file`;
open (PIPE, "cmd 2>some_file |");
You can also use file-descriptor redirection to make STDERR a duplicate
of STDOUT:
$output = `$cmd 2>&1`;
open (PIPE, "cmd 2>&1 |");
Note that you *cannot* simply open STDERR to be a dup of STDOUT in your
Perl program and avoid calling the shell to do the redirection. This
doesn't work:
open(STDERR, ">&STDOUT");
$alloutput = `cmd args`; # stderr still escapes
This fails because the open() makes STDERR go to where STDOUT was going
at the time of the open(). The backticks then make STDOUT go to a
string, but don't change STDERR (which still goes to the old STDOUT).
Note that you *must* use Bourne shell (sh(1)) redirection syntax in
backticks, not csh(1)! Details on why Perl's system() and backtick and
pipe opens all use the Bourne shell are in the versus/csh.whynot article
in the "Far More Than You Ever Wanted To Know" collection in
http://www.cpan.org/misc/olddoc/FMTEYEWTK.tgz . To capture a command's
STDERR and STDOUT together:
$output = `cmd 2>&1`; # either with backticks
$pid = open(PH, "cmd 2>&1 |"); # or with an open pipe
while (<PH>) { } # plus a read
To capture a command's STDOUT but discard its STDERR:
$output = `cmd 2>/dev/null`; # either with backticks
$pid = open(PH, "cmd 2>/dev/null |"); # or with an open pipe
while (<PH>) { } # plus a read
To capture a command's STDERR but discard its STDOUT:
$output = `cmd 2>&1 1>/dev/null`; # either with backticks
$pid = open(PH, "cmd 2>&1 1>/dev/null |"); # or with an open pipe
while (<PH>) { } # plus a read
To exchange a command's STDOUT and STDERR in order to capture the STDERR
but leave its STDOUT to come out our old STDERR:
$output = `cmd 3>&1 1>&2 2>&3 3>&-`; # either with backticks
$pid = open(PH, "cmd 3>&1 1>&2 2>&3 3>&-|");# or with an open pipe
while (<PH>) { } # plus a read
To read both a command's STDOUT and its STDERR separately, it's easiest
to redirect them separately to files, and then read from those files
when the program is done:
system("program args 1>program.stdout 2>program.stderr");
Ordering is important in all these examples. That's because the shell
processes file descriptor redirections in strictly left to right order.
system("prog args 1>tmpfile 2>&1");
system("prog args 2>&1 1>tmpfile");
The first command sends both standard out and standard error to the
temporary file. The second command sends only the old standard output
there, and the old standard error shows up on the old standard out.
--------------------------------------------------------------------
The perlfaq-workers, a group of volunteers, maintain the perlfaq. They
are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.
If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
------------------------------
Date: Mon, 28 Sep 2009 22:00:04 GMT
From: PerlFAQ Server <brian@theperlreview.com>
Subject: FAQ 8.36 How do I fork a daemon process?
Message-Id: <Elawm.23338$6f4.12610@newsfe08.iad>
This is an excerpt from the latest version perlfaq8.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .
--------------------------------------------------------------------
8.36: How do I fork a daemon process?
If by daemon process you mean one that's detached (disassociated from
its tty), then the following process is reported to work on most Unixish
systems. Non-Unix users should check their Your_OS::Process module for
other solutions.
* Open /dev/tty and use the TIOCNOTTY ioctl on it. See tty for
details. Or better yet, you can just use the POSIX::setsid()
function, so you don't have to worry about process groups.
* Change directory to /
* Reopen STDIN, STDOUT, and STDERR so they're not connected to the old
tty.
* Background yourself like this:
fork && exit;
The Proc::Daemon module, available from CPAN, provides a function to
perform these actions for you.
--------------------------------------------------------------------
The perlfaq-workers, a group of volunteers, maintain the perlfaq. They
are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.
If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
------------------------------
Date: Tue, 29 Sep 2009 02:24:00 -0500
From: tadmc@seesig.invalid
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.9 $)
Message-Id: <fLednbt-Bo2NK1zXnZ2dnUVZ_t6dnZ2d@giganews.com>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.9 $)
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://www.rehabitation.com/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 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" 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_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 and many others on the comp.lang.perl.misc newsgroup.
--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher\100cmdat/"
------------------------------
Date: Mon, 28 Sep 2009 17:16:44 -0400
From: "Uri Guttman" <uri@StemSystems.com>
Subject: the solution to some of the world's big problems is CPAN
Message-Id: <878wfyixc3.fsf@quad.sysarch.com>
CPAN
------------------------------
Date: Mon, 28 Sep 2009 14:57:24 -0700
From: Keith Keller <kkeller-usenet@wombat.san-francisco.ca.us>
Subject: Re: the solution to some of the world's big problems is CPAN
Message-Id: <43o7p6xdir.ln2@goaway.wombat.san-francisco.ca.us>
On 2009-09-28, Uri Guttman <uri@StemSystems.com> wrote:
>
> CPAN
Is that the World::Solutions module?
--keith
--
kkeller-usenet@wombat.san-francisco.ca.us
(try just my userid to email me)
AOLSFAQ=http://www.therockgarden.ca/aolsfaq.txt
see X- headers for PGP signature information
------------------------------
Date: Mon, 28 Sep 2009 18:15:18 -0400
From: sreservoir <sreservoir@gmail.com>
Subject: Re: the solution to some of the world's big problems is CPAN
Message-Id: <h9rchm$jml$1@aioe.org>
Keith Keller wrote:
> On 2009-09-28, Uri Guttman <uri@StemSystems.com> wrote:
>> CPAN
>
> Is that the World::Solutions module?
>
> --keith
>
>
No, unimport of World::Problems does that.
Like this:
no World::Problems;
--
"Six by nine. Forty two."
"That's it. That's all there is."
"I always thought something was fundamentally wrong with the universe"
------------------------------
Date: Mon, 28 Sep 2009 15:00:50 -0600
From: "Robin" <robin1@cnsp.com>
Subject: the solution to some of the world's big problems
Message-Id: <h9r8ab$tts$3@adenine.netfront.net>
The solution to some of the world's big problems. Please go here.
http://solutiontotheworldsbigproblems.heliohost.org/
--
Robin
--
robin1@cnsp.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>
Administrivia:
To submit articles to comp.lang.perl.announce, send your article to
clpa@perl.com.
Back issues are available via anonymous ftp from
ftp://cil-www.oce.orst.edu/pub/perl/old-digests.
#For other requests pertaining to the digest, send mail to
#perl-users-request@ruby.oce.orst.edu. Do not waste your time or mine
#sending perl questions to the -request address, I don't have time to
#answer them even if I did know the answer.
------------------------------
End of Perl-Users Digest V11 Issue 2615
***************************************
