[23674] in Perl-Users-Digest
Perl-Users Digest, Issue: 5881 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Dec 2 06:05:42 2003
Date: Tue, 2 Dec 2003 03:05:08 -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 Tue, 2 Dec 2003 Volume: 10 Number: 5881
Today's topics:
[Newbie]Problem reading text file <senthil.raja@adcc.alcatel.be>
Re: [Newbie]Problem reading text file <tore@aursand.no>
Capture external command output line by line on Windows <DibUrim@hotmail.com>
Re: Capture external command output line by line on Win <ben.liddicott@comodogroup.com>
Re: Display error message if an error occurs on "open" <tore@aursand.no>
Re: Display error message if an error occurs on "open" <dha@panix.com>
Easy Field Grabbing Question <Geezer@Freezer.com>
Re: First Perl Question - about sorting numeric arrays <goodcall__1@hotmail.com>
Re: First Perl Question - about sorting numeric arrays (Sam Holden)
Re: Generating Day of Week in Pure Perl <tom@nosleep.net>
Re: Generating Day of Week in Pure Perl <tore@aursand.no>
Re: Is there a command that will return the version of <nospam@bigpond.com>
Re: Is there a command that will return the version of <bigiain@mightymedia.com.au>
Re: pack, Win32 registry & binary data <ben.liddicott@comodogroup.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Re: Regex Question (max)
Re: Session Management? <ubl@schaffhausen.de>
Re: Starting Perl Script at Bootup (Tad McClellan)
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Tue, 02 Dec 2003 11:01:45 +0530
From: Senthil Raja <senthil.raja@adcc.alcatel.be>
Subject: [Newbie]Problem reading text file
Message-Id: <3FCC23C1.1ED31E49@adcc.alcatel.be>
Hello All,
I have problem reading a test file, line by line. I've written the
following code :-
/* $parse has a file path */
if (!-e $parse) { die ("Error - File \"$parse\" does not exists\n"); }
if (!open (PARSE, "$parse")) { die ("Error - Unable to open \"$parse\"
for reading. Check permissions\n"); }
while (<PARSE>)
{
/* I process the line in $_ */
/* If the line matches a particular pattern, I'll extract the no. of
further lines present in the file to be processed for this format */
/* Let $record be the no. of further lines to be processed */
for ($i=1; $i<=$record; $i++)
{
$line = <PARSE>;
}
/* After coming out of the for loop, go back and continue the while
loop to retrieve next line */
>>>>>>>>>Problem is here. The while loop terminates abruptly <<<<<<<<<<<
}
Is there anything wrong in the algorithm I use? Am I missing a basic
concept?
TIA,
Senthil.
------------------------------
Date: Tue, 02 Dec 2003 07:44:27 +0100
From: Tore Aursand <tore@aursand.no>
Subject: Re: [Newbie]Problem reading text file
Message-Id: <pan.2003.12.02.06.16.32.838434@aursand.no>
On Tue, 02 Dec 2003 11:01:45 +0530, Senthil Raja wrote:
> /* $parse has a file path */
> if (!-e $parse) { die ("Error - File \"$parse\" does not exists\n"); }
> if (!open (PARSE, "$parse")) { die ("Error - Unable to open \"$parse\"
> for reading. Check permissions\n"); }
Why are you using the ! operator all the time? IMO it's often hard to see
it, and there's more logic behind this code;
open(PARSE, $parse) or die "Couldn't open '$parse'; $!\n";
You don't _have to_ check if it exists before you try to open the file;
The code above will 'die' and tell you what went wrong - also if the file
doesn't exist.
> while (<PARSE>)
> {
> /* I process the line in $_ */
> /* If the line matches a particular pattern, I'll extract the no. of
> further lines present in the file to be processed for this format */
> /* Let $record be the no. of further lines to be processed */
> for ($i=1; $i<=$record; $i++)
> {
> $line = <PARSE>;
> }
> /* After coming out of the for loop, go back and continue the while
> loop to retrieve next line */
>>>>>>>>>>Problem is here. The while loop terminates abruptly <<<<<<<<<<<
>
> }
Please post the _complete_ code of your while() block. I can't see
anywhere that $record is being set. Are you sure that the _logic_ behind
your code works?
--
Tore Aursand <tore@aursand.no>
"War is too serious a matter to entrust to military men." -- Georges
Clemenceau
------------------------------
Date: Tue, 2 Dec 2003 10:42:22 +0200
From: "Dib Urim" <DibUrim@hotmail.com>
Subject: Capture external command output line by line on Windows 98, shell problem.
Message-Id: <bqhjf6$iif$1@news2.netvision.net.il>
Hello,
I'm trying to Capture external command output and error line by line.
There is no problem to implement it on windows 2000, but in Windows 98
you need a special shell.
The only shell that I found and it really work with is: stderr.exe*
This code is work fine on w98:
open(PROC,"stderr.exe $some_command |");
while(<PROC>) {
print ("$_");
}
close(PROC);
But the point is that it fail when I'm specify full path for "stderr.exe"
(becuase I'm exe file using perlapp and --bind don't help)
For example:
open(PROC,"C:/dir_name/stderr.exe $some_command |");
while(<PROC>) {
print ("$_");
}
close(PROC);
My questions are:
1) Why can't I specify full path ?
2) Do you know any alternative shell that work on Windows 98 using pipe.
Regards
------------------------------
Date: Tue, 2 Dec 2003 09:46:11 -0000
From: "Ben Liddicott" <ben.liddicott@comodogroup.com>
Subject: Re: Capture external command output line by line on Windows 98, shell problem.
Message-Id: <bqhn3e$gh5$1@kylie.comodogroup.com>
Hi Dib,
You need to put the full path in quotes, if it contains any spaces, =
which it often will on Win32.
open(PROC,qq[stderr.exe "$some_command" |]);
Cheers,
Ben Liddicott
"Dib Urim" <DibUrim@hotmail.com> wrote in message =
news:bqhjf6$iif$1@news2.netvision.net.il...
> Hello,
>=20
> I'm trying to Capture external command output and error line by line.
> There is no problem to implement it on windows 2000, but in Windows 98
> you need a special shell.
> The only shell that I found and it really work with is: stderr.exe*
>=20
> This code is work fine on w98:
>=20
> open(PROC,"stderr.exe $some_command |");
------------------------------
Date: Tue, 02 Dec 2003 07:10:44 +0100
From: Tore Aursand <tore@aursand.no>
Subject: Re: Display error message if an error occurs on "open" command
Message-Id: <pan.2003.12.02.03.33.51.162216@aursand.no>
On Mon, 01 Dec 2003 18:41:51 -0800, Geek wrote:
> open (MAIL2, $blatString));
>
> I'd like something that displays the actual error encountered, [...]
Use the $! operator.
--
Tore Aursand <tore@aursand.no>
"To cease smoking is the easiset thing I ever did. I ought to know,
I've done it a thousand times." -- Mark Twain
------------------------------
Date: Tue, 2 Dec 2003 06:27:31 +0000 (UTC)
From: "David H. Adler" <dha@panix.com>
Subject: Re: Display error message if an error occurs on "open" command
Message-Id: <slrnbsoc6j.2qc.dha@panix2.panix.com>
In article <pan.2003.12.02.03.33.51.162216@aursand.no>, Tore Aursand wrote:
> On Mon, 01 Dec 2003 18:41:51 -0800, Geek wrote:
>> open (MAIL2, $blatString));
>>
>> I'd like something that displays the actual error encountered, [...]
>
> Use the $! operator.
s/operator/variable/;
dha
--
David H. Adler - <dha@panix.com> - http://www.panix.com/~dha/
DHA is the "Smorax", he is friends with the Twinkies and speaks for
the Choc-O-Diles. - Mark Rogaski
------------------------------
Date: Tue, 02 Dec 2003 09:57:49 +0000
From: Geezer From Freezer <Geezer@Freezer.com>
Subject: Easy Field Grabbing Question
Message-Id: <3FCC621D.AE30FD53@Freezer.com>
I've had a look in some books but can't find what I'm looking for.
I have a line of text in a variable or several in an array
and I want to extract the 5th field of each line - how?
------------------------------
Date: Tue, 02 Dec 2003 05:09:06 GMT
From: "Jack D." <goodcall__1@hotmail.com>
Subject: Re: First Perl Question - about sorting numeric arrays
Message-Id: <S7Vyb.91814$oN2.42636@edtnps84>
"BKennedy" <b_t_k@hotmail.com> wrote in message
news:53240d5a.0312012101.2b261184@posting.google.com...
> Hello,
>
> Well here goes my first newbie PERL question for the gurus of this
> group. My issue is with using the SORT instruction. Below you'll
> find the printed contents of 5 element array before and after a
> 'sorting'. Is the 'sorting' being performed on the references and not
> the contents? I don't understand why the numbers are sometimes not in
> proper sequence after the SORT. (Shouldn't the second printing of the
> first array read : 5 9 13 13 14 ?)
>
> for $a(0..3)
> {
> for($i=0;$i<5;$i++)
> {
> $array[$i] = int(rand(19) +1);
> }
> print("$a\t @array \n");
Stop right here. Read:
perldoc -q sort
before you write your next line.
> @array = sort @array;
> print("$a\t @array \n");
> }
>
> Results:
> 0 14 13 13 9 5
> 0 13 13 14 5 9
> 1 11 10 5 12 15
> 1 10 11 12 15 5
> 2 8 16 7 14 13
> 2 13 14 16 7 8
> 3 12 6 12 5 4
> 3 12 12 4 5 6
>
> Any help is appreciated. Thanks.
>
> -Bkennedy
------------------------------
Date: 2 Dec 2003 05:11:11 GMT
From: sholden@flexal.cs.usyd.edu.au (Sam Holden)
Subject: Re: First Perl Question - about sorting numeric arrays
Message-Id: <slrnbso7nf.8um.sholden@flexal.cs.usyd.edu.au>
On 1 Dec 2003 21:01:32 -0800, BKennedy <b_t_k@hotmail.com> wrote:
> Hello,
>
> Well here goes my first newbie PERL question for the gurus of this
> group. My issue is with using the SORT instruction. Below you'll
> find the printed contents of 5 element array before and after a
> 'sorting'. Is the 'sorting' being performed on the references and not
> the contents? I don't understand why the numbers are sometimes not in
> proper sequence after the SORT. (Shouldn't the second printing of the
> first array read : 5 9 13 13 14 ?)
No because you are doing a string sort and the string "5" comes
later than the string "13" when sorted into dictionary order,
just like "e" comes after "ac".
perldoc -f sort
Provides numerous examples on how to use the sort function,
including sorting numerically.
You should read the posting guileines that are posted here frequently.
It is also available at:
http://mail.augustmail.com/~tadmc/clpmisc/clpmisc_guidelines.html
--
Sam Holden
------------------------------
Date: Mon, 1 Dec 2003 22:40:51 -0800
From: "Tom" <tom@nosleep.net>
Subject: Re: Generating Day of Week in Pure Perl
Message-Id: <3fcc40fc$1@nntp0.pdx.net>
"rev" <rev@TheWaterCooler.com> wrote in message
news:7qOyb.28801$2y3.5045@newssvr29.news.prodigy.com...
> I have a date formatted like so MM/DD/YYYY (e.g. 12/01/2003) and I need
> to get the day of the week from this (Monday). But, this is occurring
> on my hosting vendor so whatever does it needs to be pure Perl.
OS?
Windows XP:
$date = `date /t`;
chomp($date);
($weekday,$tmp1) = split (/\s+/, $date);
UNIX(Linux):
$date = `date`;
# $date = "Sun Aug 31 5:12:57 PDT 2003"; # < Sample
chomp($date);
($weekday,$month,$day,$ctime,$timezone,$year) = split (/\s+/, $date);
------------------------------
Date: Tue, 02 Dec 2003 07:57:12 +0100
From: Tore Aursand <tore@aursand.no>
Subject: Re: Generating Day of Week in Pure Perl
Message-Id: <pan.2003.12.02.06.55.45.507817@aursand.no>
On Mon, 01 Dec 2003 22:40:51 -0800, Tom wrote:
>> I have a date formatted like so MM/DD/YYYY (e.g. 12/01/2003) and I need
>> to get the day of the week from this (Monday). But, this is occurring
>> on my hosting vendor so whatever does it needs to be pure Perl.
> OS?
The OP was talking about "pure Perl". Why drag the OS into this case?
> Windows XP:
>
> $date = `date /t`;
> chomp($date);
> ($weekday,$tmp1) = split (/\s+/, $date);
>
> UNIX(Linux):
>
> $date = `date`;
> # $date = "Sun Aug 31 5:12:57 PDT 2003"; # < Sample
> chomp($date);
> ($weekday,$month,$day,$ctime,$timezone,$year) = split (/\s+/, $date);
This is hardly "pure Perl".
--
Tore Aursand <tore@aursand.no>
"A car is not the only thing that can be recalled by its maker." --
Unknown
------------------------------
Date: Tue, 02 Dec 2003 18:06:16 +1000
From: Gregory Toomey <nospam@bigpond.com>
Subject: Re: Is there a command that will return the version of perl?
Message-Id: <2525430.M6Wg5aDTAh@gregs-web-hosting-and-pickle-farming>
It was a dark and stormy night, and Guy managed to scribble:
> I am writing a perl script for someone. They gave me the address to one of
> their unix servers and they created a couple of directories for me
> including a cgi-bin where I can save my .cgi files (actually I was used to
> .pl files but I guess they have to be .cgi on this server).
>
> I upload my files to the server using FTP.
> I can telnet to it but I think the only access I have is to my
> directories.
>
> The server is about 3 hours away from here.
>
> I was wondering, if my perl script can detect what version of perl it's
> running on. whether it's perl 5.004, 5.6, or whatever.
>
> Or is there an ENV value that I can pick up on it.
>
> Thanks for all,
>
> Guy Doucet
$] contains the version number.
print $];
For a full list of special variables see http://www.rexswain.com/perl5.html
gtoomey
------------------------------
Date: Tue, 02 Dec 2003 19:19:58 +1100
From: Iain Chalmers <bigiain@mightymedia.com.au>
Subject: Re: Is there a command that will return the version of perl?
Message-Id: <bigiain-D372A3.19195802122003@news.fu-berlin.de>
In article <2525430.M6Wg5aDTAh@gregs-web-hosting-and-pickle-farming>,
Gregory Toomey <nospam@bigpond.com> wrote:
> Guy wrote:
> >
> > I was wondering, if my perl script can detect what version of perl it's
> > running on. whether it's perl 5.004, 5.6, or whatever.
>
> $] contains the version number.
> print $];
>
> For a full list of special variables see http://www.rexswain.com/perl5.html
Or even (from a command line):
perldoc perlvar
it magically works even without a net connection!
:-)
big
--
'When I first met Katho, she had a meat cleaver in one hand and
half a sheep in the other. "Come in", she says, "Hammo's not here.
I hope you like meat.' Sharkey in aus.moto
------------------------------
Date: Tue, 2 Dec 2003 10:53:25 -0000
From: "Ben Liddicott" <ben.liddicott@comodogroup.com>
Subject: Re: pack, Win32 registry & binary data
Message-Id: <bqhqv9$o6s$1@kylie.comodogroup.com>
Hi Woof,
Win32 has a number of data/time formats, more than one of which is 64 =
bits long.
Ole's DATE type is a 64 bit floating-point number, containing the number =
of days since the DATE epoch, which is Midnight on the morning of Dec =
30, 1899. The fractional part is therefore the time of day.
Win32's FILETIME is a 64 bit integer, specifying the number or 100 =
nanosecond intervals since the January 1, 1601.
MS CRT's _time_64_t is a 64 bit integer, but the value given here puts =
it in the future, as it is in seconds since the C epoch.
QueryPerformanceCounter returns a 64-bit integer... but the frequency =
and base change from machine to machine, and boot to boot.
My guess is that you have a something else altogether though, as that =
number doesn't seem to unpack to a recent time using any of the above.
Neither of these will go into Perl's localtime function, but any can be =
made into a date string without too much trouble. If you have a FILETIME =
you can use Win32API::Time to unpack it.
Cheers,
Ben Liddicott
"woof" <drubnone@yahoo.com> wrote in message =
news:7b21a826.0312010647.6248a666@posting.google.com...
> I need an example on how to collect and process REG_BINARY data
> in a Win32 registry. The registry value in question reads:
>=20
> TimeOfLastScan REG_BINARY 21 0a 1e 0d 00 1e 00 00
>=20
> It appears to be 8 bytes... an unsigned long ("L")?
>=20
> Reading strings seems easy enough as in
> my $parent =3D $rkeyNorton->{"CurrentVersion//Parent"};
>=20
> I did try and read this binary value with (cvKey set to =
CurrentVersion);
>=20
> (my $gvtimeOfLastScan, my $type) =3D =
$cvKey->GetValue("TimeOfLastScan");
>=20
> But have been unable to feed localtime() anything that gets
> me my date string. I know I'm not packing this correctly.
------------------------------
Date: Tue, 02 Dec 2003 02:23:22 -0600
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.4 $)
Message-Id: <HPGdnddJsotn1lGiRVn-sQ@august.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($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: 2 Dec 2003 00:36:01 -0800
From: hjkmax@netscape.net (max)
Subject: Re: Regex Question
Message-Id: <95401f7d.0312020036.6995d94a@posting.google.com>
A few sleepless nights,
I think this is what I was looking for!
Which is checking the are zero or more multiples of two backslash
without any other backslash behind the field delimitor, which in this
case is the duble quote equels character pair.
Don't know if it is the best way of doing this, let me know if you
have any other ideas, for dealing with escape characters?
Thanks anyway
Max
(.*?)((?:[^\\](?:[\\]{2})*)"=)(.*)
which should split any patten with an escape backslash into $1 "= $3.
> > > How do I deal with escaped backslash in patterns?
> > > Hope the is some light out there...
> > > I want to match (dublequote anything dublequote) followd by equels
> > > like ("something"=something)
> > >
> > > here are some of the problem pattern
> > >
> > > "=\"=\"=\""="=\"=\"=\"" "\\\\\\\\\\"="\\\\\\\\\\" "==="="==="
> > >
> > > This is what I have so far.
> > > I just don't seem to be able to match the no \ before "= unless the are two \\
> > > I seem to be able to do one pattern but not all of them!
> > >
> > > m/
> > > ^" #begining of line duble quote
> > > (.*? #anything minimul match
> > > )
> > > (?:(?<!\\) #( exept before a back slash
> > > "=) # a duble quote followed by a equal sign)
> > > (.*) #anything after
> > > /x ;
> > > or
> > > m/
> > > ^" #begining of line duble quote
> > > (.*? #anything minimul match
> > > )
> > > (?: #exept before a back slash
> > > "=) #a duble quote folowed by a equal sign
> > > (.*) #anything after
> > > /x ;
> > >
> > > Sorry about the unclarity of the mess
> > > Thanks
> > > Max
> >
> >
> > If I understood you right, you want to match some thnig like ("X"=X)?
> > So I think you need to use:
> > m/\("(.*?)"=\1\)/
> >
> > Tell me if I misunderstood...
>
> Sorry, it is not so clear, I will try again...
> I am trying to split something a paten like "anything"=something_else
> but with the rule that if the (anything or something_else) has a " or
> \ inside
> it is escaped with a \,
> So (any\thing) would become (any\\thing), and (anyth"ing) would become
> (anyth\"ing).
> So I think am trying to match anything(not \\ or \")then"=(and some
> more anything).
> Or to put it another way [^\]\""= and [^\]\\"= are ok, [^(not even
> number of backslash)\"= is not as you get an escaped " .
>
> Maybe I am looking at this from the wrong angel!
> I did have a look at:
> "How can I split a [character] delimited
> string except when inside [character]?"
> Seems to be something like m/"([^"\\]*(\\.[^"\\]*)*)"|([^,]+)/g
> m/
> "
> (
> [^"\\]* #not [" or \] 0 or more times
> (\\. [^"\\]*) #\ one chr not [a " or \]0 or more times
> *) # 0 or more times
> "
> | #or
> (
> [^,]+) #not 1 or more ,
> /g;
> I don't see how this helps and the line in the faq is no better at
> explaning, Sorry
> Max
------------------------------
Date: Tue, 02 Dec 2003 10:36:38 +0100
From: Malte Ubl <ubl@schaffhausen.de>
Subject: Re: Session Management?
Message-Id: <bqhphg$bka$1@news.dtag.de>
Z Monteca wrote:
> I just did an implementation of sessions. Personally I used
> Apache::Session::File, but I see others have used CGI::Session. Does
> anyone have any pros/cons they could lend on using this method/module for
> management.
>
> So far the one problem that I have run into is all the garbage clean I up
> that has to be done. For every web request that is made it seems to create
> a lot of unecessary session files in the session directory (after a few
> hours I have upwards of 10's of thousands, but only have a few thousand
> hits a day ~2,000). I am not sure why this is. A true con is that you have
> to have run a cron script to clean up this directory every few hours. Is
> this a standard element of using the Apache::Session::File module or is my
> implementation seem to be messed up a bit?
Apache::Session defines an interface to be extended with other backend
storage machanims. I like Apache::Session::CacheAny that uses the
Cache::Cache interface. This enables you to use in memory cache which
might be more appropriate for you.
malte
------------------------------
Date: Mon, 1 Dec 2003 22:20:30 -0600
From: tadmc@augustmail.com (Tad McClellan)
Subject: Re: Starting Perl Script at Bootup
Message-Id: <slrnbso4oe.4k5.tadmc@magna.augustmail.com>
Matt <nospam@yahoo.com> wrote:
> I have a perl script I would like to have run every time my server boots up.
> Its running Redhat Linux. How would I do that?
The same way you would if it was a Python or shell script.
You have an OS question, not a programming question. Search
Google groups (comp.os.linux.*) or ask in an OS newsgroup.
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
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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