Notes » perl

Perl CGI

Alex — Wed, 13 Oct 2010 00:35:51 +0000

PSGI

Plack

Plack::Middleware::StackTrace

Excel Deletes Leading 0s When Opening a CSV File

Alex — Thu, 01 Jul 2010 21:43:30 +0000

If you want Excel to keep a field’s leading zeros when opening a CSV file using Excel, you can change it to =”value”.

For example, if you have a row with 4 values that looks like this:

test,00016102,test,test

Just change it to:

test,="00016102",test,test

How to use Perl’s ternary operator

Alex — Tue, 07 Jul 2009 03:46:21 +0000

The Ternary Operator

The ternary is actually a sequence of operators. The operator is used like this:

CONDITION-PART ? TRUE-PART : FALSE-PART

which is shorthand for the following statement:

if (CONDITION-PART) {

TRUE-PART

} else {

FALSE-PART

}

Example: If $firstVar is zero, then assign $secondVar a value of zero. Otherwise, assign $secondVar the value in the first element in the array @array.

$secondVar = ($firstVar == 0) ? 0 : $array[0];

via Perl 5 By Example.

Check String for Non-ASCII Characters in Perl

Alex — Sat, 01 Nov 2008 20:19:21 +0000

if ( $string =~ /[[:^ascii:]]/ ) { print "String contains characters that are NOT pure ASCII"; } else { print "Everything is good, string/pure is valid ASCII."; }

E.G.: If it contains bytes > 127, it’s not valid ASCII.

Active Perl’s Package Manager: ppm

Alex — Thu, 07 Aug 2008 02:06:54 +0000

It allows you to get Perl pre-compiled packages. You can avoid installing a C compiler which is needed for some packages (KinoSearch for example).

http://aspn.activestate.com/ASPN/Downloads/ActivePerl/PPM/

Alternate packages repositories:
http://cpan.uwinnipeg.ca/PPMPackages/10xx/

Perl’s KinoSearch vs Plucene

Alex — Fri, 18 Jul 2008 02:33:59 +0000

KinoSearch is the winner

The following perl scripts index *.txt in the current folder and search for “TEST”. The first one is using Perl’s KinoSearch module and the other one is using Plucene. KinoSearch is alot faster then Plucene and also gives better results.

(right click to download)

KinoSearch.pl

Plucene.pl

Install a Perl Module on a Shared Host

Alex — Tue, 25 Sep 2007 21:16:26 +0000

Setup cpan:

$ mkdir ~/perl
$ mkdir -p ~/.cpan/CPAN
$ touch ~/.cpan/CPAN/MyConfig.pm
$ cpan

cpan> o conf init

Set the following settings:

'cpan_home' => q[/home/username/.cpan],
'build_dir' => q[/home/username/.cpan/build]
'keep_source_where' => q[/home/username/.cpan/sources],
'makepl_arg' => q[PREFIX=~/perl]
'mbuildpl_arg' => q[--install_base /home/username]

Get and Install the Module
- Automatically
  - ```
  $ cpan force install Module::Name
```
Make sure Perl can find your modules

Add this line in each of your Perl scripts (change perl version accordingly):

use lib '/home/your_username/perl/lib/perl5/site_perl/5.8.7';

OR rather than editing all your Perl scripts, in your cgi-bin/.htaccess file:

SetEnvIf  Request_URI  "^/cgi-bin/" PERL5LIB=/home/user/perl/lib/perl5/site_perl/5.8.7:/home/user/perl/lib/perl5/site_perl/5.8.7/site_perl

OR in your .bash_profile:

export PERL5LIB=/home/user/perl/lib/perl5/site_perl/5.8.7:/home/user/perl/lib:/home/user/perl/lib/perl5:/home/user/perl/lib/perl5/site_perl

It won’t be effective until you log back in, if you want to make it effective in your current session, just type that line in your command prompt.