Esteemed monks,

I am designing a Catalyst application (my first), which I hope to run as a single instance, with single sign-on, across multiple subdomains.

I have found the Catalyst::Action::SubDomain module, which looks very promising. The documentation is fairly sparse, and does not addresses any domain/server configuration required in order to run a single instance as I propose.

My questions are:

1. In order to have a single Catalyst app instance running across multiple subdomains, must those subdomains be mirrored domains (i.e., using Apache's ServerAlias directive)?
2. In order to have single sign-on between domains, must I use a wildcard domain in the session cookie?
3. Most of all, is Catalyst::Action::Subdomain the best choice for determining within my app which domain the request is going to, so that the app can be customized for each domain?

Thank you for your time and consideration.

Hello All,

Up till now I have been coding fairly simple Perl scripts.

Lately I have started designing some complex scripts. And I always felt that if you place the logic and flow of the script on paper first then coding part is simplified to a great extent. And up till now I have mainly used pen and paper for it. :)

Was just wondering if there is any graphical tool (of course opensource :)) specific to Perl to design the flow of the Perl script projects before we actually start coding it.

Using it I should be able to design something similar to flowcharts and should be able to share it with others to get it reviewed.

So just wanted to know which tool does Perl developers use in general to design the flow of the Perl projects.

TIA

Parag

Greets,

I have often seen people badmouth the bytes pragma, but there's one thing I use it for: cheaply identifying empty strings with bytes::length()when the strings may be carrying the SVf_UTF8 flag. The length() function can be inefficient for such strings, because it must traverse the entire buffer counting characters:

marvin@smokey:~/perltest $ perl compare_length_efficiency.pl 
        Rate  utf8 bytes
utf8  4.35/s    --  -98%
bytes  185/s 4154%    --
marvin@smokey:~/perltest $ 
[download]

Is there an efficient alternative to bytes::length() for this use case elsewhere in core?

use strict;
use warnings;

my %people;
my @sentences = ("here i am","i am me");
$people{me}[0] = 0; 
$people{me}[1] = "1985";
$people{me}[2] = @sentences;

@sentences = ("there she is");
$people{friend}[0] = 1;
$people{friend}[1] = "1984";
$people{friend}[2] = @sentences;

foreach my $person ( %people) 
{
  my $rowId = $person[0];
  my $dob = $person[1];   

  addDOBToDatabase($rowId, $dob);
  foreach my $sentence ( %sentences) 
  {
    addSentenceToDatabase($rowId, $sentence);
  }  
}
[download]

Hi everyone,

I've now been registered on the PAUSE, and now am contemplating on the naming of what I've been working on.

One of the projects is essentially an integrated Internet Service Provider management system. It contains 9 modules, a full client record and ledger management system, a sales transaction system, client accounts/plans system all which backs to a database (SQLite & MySQL tested). It also has a web GUI front-end that overlays it all.

That project has additional features if other modules I have written are installed.

The primary external module is a RADIUS database management system. Its purpose is to allow easy management of all FreeRADIUS database tables. Particularly, it aggregates all of the accounting information, archives data, produces accounting reports for billing etc.

Currently, my naming is as such:

ISP::

• ::Core
• ::User
• ::Transac
• ::Ledger
• ::GUI::Accounting
• etc

ISP::RADIUS

ISP::Email

Given that all of these projects/modules are directly related to the operation of an ISP (with more in the works), I'm looking for feedback if this would warrant a new top-level namespace (ISP) on the CPAN, and how people generally feel about new top-level namespaces being requested.

Any and all feedback appreciated. Cheers!

Steve

I'm writing a web spider, using LWP::RobotUA, and running it on WinXP (ActivePerl). When I retrieve certain webpages, the anchor parsing (which uses HTML::TokeParser) just dies, in the middle of printing out a progress report, if I have tracing turned on, or later, if not. I have handled all the sigs, and the (single, common) handler is never invoked (though I have tried to manually invoke a few sigs, and they seem to work fine). Failure seems to be 100% repeatable, so far, stopping at the exact same char of printout in each case.

I would suspect that memory allocation failure is at the root of this, but have no idea how to confirm that suspicion... the failing pages (5 so far, completely unrelated to each other) all seem fairly long - over 80k. However, most other, much longer (200k+) pages parse quite successfully.

Is there any known way to trap a memory allocation failure?

Is there any known way to trap any other normally silent failure? (and what might fall into this category?)

Thanks, for any ideas or pointers. I am a noob to perl, but have >40 years experience programming... so I probably have some incorrect assumptions that are blinding me.

Dick Martin Shorter

As my first assignment in my new job ramps up, one task I've taken on is to resolve L10N issues. From the looks of things, I think Locale::Maketext looks to have addressed 90%+ of the issues (though if they could have packaged in base classes that help with double-byte, or other locale, issues, that'd have been great - they seemed to know about some issues, just leaving handling them as excersises for the users). One substantial piece left unresolved is the creation of the base language class (usually English). They provide an _AUTO option, which looks useful, until I found out that, well, it didn't write the updates back to the English module, which would make it harder to create the modules for the other languages.

Also missing is the "delta" - that is, merging those keys, but with empty values, into the other languages' modules.

The first thing popping into my head would be to use something like PPI to look for the maketext calls and extract the first parameter and then use that to update all the language files (as both key and value for English, and just key with empty value for other languages). Manually updating English is already annoying, so that'd actually be the second thing that popped into my head, and it doesn't actually resolve the other-languages issue to send to the translators.

I'm wondering if anyone else has dealt with this already, and what approach you took? Is "use utf8;" required at the top of these files?

I'm looking for some hints on how to write a module which adds new (and largely superfluous) operators to Perl, specifically to replicate Fortran's .EQV. and .NEQV. logical operators. I won't argue that these are useful additions to Perl–I've programmed Fortran for close to forty years and never used either–but it does seem like a fun little project.

Hi! I have very large text files (10GB to 15GB). Each one contains about 40 million lines and 7 fields (see example below).

File looks like this:
99_999_852_F3    chr9    97768833    97768867    ATTTTCTTCAATTACATTTCC
+AATGCTATCCCAAA    +    35
99_999_852_F3    chr9    97885645    97885679    ATTTTCTTCAaTTACATTTCC
+AATGCTATCCCAAA    +    35
99_99_994_F3    chr10    47028821    47028855    AGACAAAAAGGCCATCAACAG
+ATCAGTAAAGGATC    +    35
...
[download]

I need to sort the files based on field-1 (ASCII sorting). I am using Unix  sort -k1 command. Although it works fine, it takes very long time, 30 min to 1 hour. I also tried following Perl script:

 
#!/usr/bin/perl
use strict;
use warnings;

open (INFILE, "inputfile.txt") or die $!;
open (OUTFILE, '>', "sorted.txt") or die $!;

foreach (sort <INFILE>){
    print OUTFILE $_;
}

close(OUTFILE);
close(INFILE);
exit;
[download]

However, this script puts entire file into memory and sorting process becomes too slow. I was wondering if someone could suggest me a Perl script that will do the sorting faster than Unix  sort -k1 command, and will not use too much memory. Thanks.

sql.pl Preable

sql.pl Non-Returning Subroutines

sql.pl Returning Subroutines

sql.pl Accessing Subroutines

my @results = &row_sql(qq~ select * from table where ...; ~);

my @results = &get_sql(qq~ select id from table where ...; ~);

my $rows = &hash_sql(qq~ select * from table; ~);
foreach my $row (@$rows){
  print "$row->{id}, $row->{somecolumn}\n";
}
[download]

Rolling your own persistent-ness

    until (
    $dbh=DBI->connect_cached($connectionInfo,$user,$passwd, {PrintErro
+r=>0} )
    ) { if ($sqlw){print "Retrying SQL Connect ($DBI::errstr) ...";} s
+leep(1); }
    
  until (
      eval {
      $sth=$dbh->prepare($insert);
    if ($sth->execute()) {
      $sth->finish;
        }
    }
    ) { if ($sqlw){print "Retrying SQL Insert ($DBI::errstr)...";} sle
+ep (1); $retry_count++;}
[download]

sql.pl :: Source Code

Wx is a pain to install on Windows using ActivePerl 5.10.1 and a MS compiler. This post details one way of installing it.

It crashes Visual Studio 6's compiler, so start by upgrading your compiler:

• Download "Visual C++ 2008 Express edition".
• Install it under C:\Progs (Adjust at will)

Now we need the library. If you let Alien::wxWidgets download and build it, it won't embed the manifest files into the DLL files, causing DLL errors and malfunctions when you try to some aspects of Wx.

• Download wxWidgets-2.8.10
• Install it in C:\Progs\wxWidgets-2.8.10 (Adjust at will)

It might be a good idea to upgrade your Perl tool chain. You want at least:

• ExtUtils-CBuilder-0.18

I had the following installed:

• ExtUtils-CBuilder-0.27
• Module-Build-0.35
• ExtUtils-MakeMaker-6.55_02

Then, open up a console and execute the following commands in turn. As is, it's not suitable to be copy and pasted in its entirety or put in a batch file.

Note that the process takes a while. The longest step, building "msw", takes an hour or more on my aging machine.

"C:\Progs\Microsoft Visual Studio 9.0\VC\vcvarsall"

C:
cd \Progs\wxWidgets-2.8.10
cd build\msw
nmake -f makefile.vc SHARED=1 BUILD=release
cd ..\..
cd contrib\build\stc
nmake -f makefile.vc SHARED=1 BUILD=release
cd ..\..\..
cd lib\vc_dll
for %q in (*.manifest) do (
   mt -nologo -manifest %q -outputresource:%~nq;2
   del %q
)
cd ..\..

set WXDIR=C:\Progs\wxWidgets-2.8.10
set WXWIN=C:\Progs\wxWidgets-2.8.10

C:
cd \
md stager
cd stager

lwp-request http://search.cpan.org/CPAN/authors/id/M/MB/MBARBON/Alien-
+wxWidgets-0.47.tar.gz > Alien-wxWidgets-0.47.tar.gz
perl -MArchive::Tar -e"Archive::Tar->new->read($ARGV[0],1,{extract=>1}
+)" Alien-wxWidgets-0.47.tar.gz
cd Alien-wxWidgets-0.47
perl -i.bak -pe"s/config => \{ cc => \$cc, ld => \K(?=\$cc })/\$cc eq 
+'cl' ? 'link' : /" lib\Alien\wxWidgets\Utility.pm
perl Makefile.PL INSTALLDIRS=site
   -> Should ask "Do you want to fetch and build wxWidgets from source
+s?". Use default "no".
nmake
nmake test
nmake install
cd ..
rd /s/q Alien-wxWidgets-0.47
del Alien-wxWidgets-0.47.tar.gz

lwp-request http://search.cpan.org/CPAN/authors/id/M/MB/MBARBON/Wx-0.9
+4.tar.gz > Wx-0.94.tar.gz
perl -MArchive::Tar -e"Archive::Tar->new->read($ARGV[0],1,{extract=>1}
+)" Wx-0.94.tar.gz
cd Wx-0.94
perl -i.bak -pe"s/^sub \K(?=dynamic_lib \{$)/DELETED_/" build\Wx\build
+\MakeMaker\Win32_MSVC.pm
perl -i.bak -pe"s/new wxCursor\( name, \K(?=type, hsx, hsy \))/(long)/
+" xs\Cursor.xs
perl Makefile.PL INSTALLDIRS=site --extra-cflags="/FIstdlib.h"
nmake
nmake test
nmake install
cd ..
rd /s/q Wx-0.94
del Wx-0.94.tar.gz

cd ..
rd stager
[download]

Finally, you may uninstall wxWidgets-2.8.10 (via Start | Programs) since Alien::wxWidgets made a copy of the files Wx needs into Perl's lib. The uninstaller leaves the built files behind, so delete the C:\Progs\wxWidgets-2.8.10 directory as a follow up. Uninstalling wxWidgets-2.8.10 will free up 500MB.

I recommend that you get Wx::Demo.

"C:\Progs\Microsoft Visual Studio 9.0\VC\vcvarsall"
cpan Wx::Demo
[download]

You can launch the demo using

wperl C:\Progs\perl5101\site\bin\wxperl_demo.pl
[download]

It warns that it's "skipping module 'Wx::DemoModules::wxHVScrolledWindow'". I think it's a problem with the demo, not a problem with Wx.

Update: Many small tweaks to the text parts. Last one on Dec 22, 2009 at 10:21 EST

I have been working on a project with the National Labs over the past several months. A central element of that work has been an effort to bring much of the information and computatiom power of the Labs into a Service Oriented Architecture paradigm and the Semantic Web constructs are at the heart of that part of the work.

Not being that familiar with the Semantic Web constructs, I embarked on a concerted effort to teach myself about it. So I have read through several books. But, for me, there is no substitute for doing some actualy programming on a topic to really do a "deep dive" into the material.

So I latched onto Segara, Evans and Taylors' "Programming the Semantic Web" (published by O'Reilly. I like O'Reilly's books, in general, and had some really good learning on their similar book "Programming Collective Intelligence."

I am a Perl programmer, through and through, and have been laboring with trying to convert the Python constructs that seem so prevalent in these SOA, Semantic Web, and Web Data Minimg "tutorials".

Out of this last few months' efforts, two questions have emerged for me.

First, why is Python so prevalent in this genere of discourse? What makes Python so preferred in the world of Collective Intelligence, Semantic Web, etc.?

Second, why is Perl so conspicuously NOT involved in those domains? I have searched extensively in CPAN and we only have a tiny handful of modules. Similarly, there are virtually no books on the topics that use Perl or are Perl-oriented.

Perl seems like an absolute natural programming language for these types of applications. I have tought myself enough Python that I don't have to struggle too hard when learning from the books. That progress learning Python, however, has taught me that I'm hard pressed to see or know why Python would be any better than Perl. Superficially, it seems that Python may be a little more compact (with constructs like its List Comprehensions); but my experience so far is that it is no easier to understand or read than obfuscated Perl which can be just as compact...and just as obscure. I take exception to the assertion in all of those books that "Python is used because it is so naturally understandable"; I don't see that at all.

So I'm curious (knowing that quite a few of you know Python much beter than I do and you all, here in the Monestary know Perl, of course) if anyone can explain the predilection for Python for those types of applications...and the dirth of Perl in them.

Just curious.

Ok, so not a fix, but a workaround. The problem is fairly well described in this blog post and this bug report for YAML::XS. The merge keys functionality of YAML is not supported by either YAML::XS or YAML::Syck, so this script:

#!/usr/bin/perl
use strict; use warnings;
use YAML::XS;
use Data::Dumper;

my $data;
{local $/;$data = <DATA>};

print Dumper Load $data;

__DATA__
---
key1: &id01
  subkey_a: asdf
  subkey_b: qwer
key2:
  <<: *id01
  subkey_a: foo
  subkey_c: bar
...
[download]

produces this output:

UPDATE: Found a couple easy ways to avoid recursion. See my reply below.

@_=qw;
Just another Perl hacker,;
;$_=q=print
"@_"= and eval;
[download]

This program converts a text file from a character encoding to another, but tries to detect if the user accidentally specifies the wrong character encoding, such as iso-8859-2 instead of utf-8.

This has a real world motivation. I'm writing a program that works by mostly copying its input to the output but annotates some parts of it. The program must accept input of multiple character encodings (iso-8859-2, utf-8, cp1250), and similarly must be able to emit the output in multiple encodings. The user can choose the input and output encodings with command-line switches. If, however, the user inputs an utf-8 file but specifies 8859-2 as the input and output encodings, the program may appear to work and output a utf-8 file. The program won't be able to understand those records that have non-ascii characters, but this might not be obvious from the output. For this reason, I added some code to detect this kinds of errors. This program here is a standalone program copying only the relevant code.

I'm not sure this is a cool use for Perl, but once again, I am astounded by how easy the easy things really are. The script below is one of those where you're almost surprised when you're done writing it. "That's it?", you ask yourself. Yes, that's it.

Here's the background: there's a certain trail race that I'd like to run, but there are always more applicants than slots, so the organizers have resorted to a lottery system to pick entrants this year. Unfortunately, I didn't get in, but I am in the top 25 on the wait list.

The lottery winners have until midnight tonight to pay their entry fee - otherwise the wait-listed people move into their slots. On the lottery page, it is clearly indicated who has, and who hasn't, paid their entry fee yet. Now I could obsessively sit at my computer, refresh the page every five minutes and count the "Not Paid" entrants... or I could be obsessive and lazy, and enlist Perl for help.

With just three use directives, I'm in business:

use LWP::UserAgent;
use HTML::TableParser;
use XML::RSS;
[download]

The script is scheduled via cron. Since I can check my news reader on my phone, I am free to walk around, eat dinner etc. while tracking something I have absolutely no control over. Perfect!

I've done something like this before, in order to track the waiver wire in a fantasy league. But I am struck by how easy this really was, and totally worthwhile even though I can put this script in the trash after midnight.

I've also thought that this basic process - scrape -> parse -> post - can be implemented in thousands of ways using many other tools and technologies. Have other monks done similar things in the past? How would you have approached my problem?

matrice sets of god
non linear equations
control the time wave
[download]

This isn't really obfuscation, it's even vaguely useful, but see if you can figure out what Pipes.pm must be doing, given that this prints o-l-l-e-H

use strict;
use warnings;
use Pipes;

print "hello" |
fn { ucfirst($_[0]) } |
fn { [ split('', $_[0]) ] } |
fn { [ reverse(@{$_[0]}) ] } |
fn { join('-', @{$_[0]}) } |
fn { $_[0] . "\n" };
[download]

perl -e 'print sub { "Hello @{[shift->()]}!\n" }->(sub{"World"})'
[download]