Quick Perl Interview Points

Some years ago when I was planning for job change one of my close friend Deepak told me if you want to crack Perl interview just revise these points. I called these as bullet points.

Just revising these points for my reference and for your help.

This is no particular order and written as mentioned by him over the phone

• Referencing – de-referencing of data types – scaler, hash, array
• pack – unpack
• string – split. while,
• pop,push,shift,unshift
• array – add variable..
• hash print
• data read from hash.
• sorting – numeric or normal
• file handing
• DB connection.
• path module.
• use warning, use strict, dbi, cgi, dump
• perl mysql connection
• regular expression – all small example
• adding module how to..
• use
• require
• my or local diff.
• package
• why we use 1 in package.
• little oops in perl
• @ISA
• command line in perl
• /usr/bin/perl
• CGI T
• use dignostic
• how to debug
• perl -d
• cpan to cgi.
• pass by value , pass by reference
• environment variable
• data type of return value.
• how to know that array has unique value
• how to run system command from perl, how many ways. 4-5 ways. diff between each
• spacial variable
• comments in regular expression
• what are the default error
• what is slurp mode
• file hander, opearion, third argument
• how to escape
• apache
• sorting – numeric or normal
• regular expression – all small example
• adding module how to..

I will keep adding new point as and when I will get.
Comment your points.

Happy Perl.

How to get Google Page-Rank from Perl Script

Today got good package by which directly we can get the google page rank.

This is the easiest way to find the google page rank from Perl Code.

I tried this code in 2 ways
1. By list in the code
2. By putting the site from command prompt.

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

use WWW::Google::PageRank;
my $pr = WWW::Google::PageRank->new;

my $page = $ARGV[0];

my @sites = (
  'http://www.yahoo.com',
  'http://www.wordpress.org',
  'http://www.wordpress.com',
  'http://www.labnol.org'
);
if(!$page) {
  foreach(@sites) {
	  print "$_ : ";
	  print scalar($pr->get($_)), "\n";
  }
} else {
  print "$page : ";
  print scalar($pr->get($page)), "\n";
}

2 Ways to run this code

ankur@ankur:~> perl googlerank.pl
http://www.yahoo.com : 9
http://www.wordpress.org : 9
http://www.wordpress.com : 9
http://www.labnol.org : 6
ankur@ankur:~> perl googlerank.pl http://www.apple.com
http://www.apple.com : 9
ankur@ankur:~>

This is the simplest code, we can change based on requirement.

Happy Perl.

Perl CPAN Reconfigure urllist

Perl CPAN Reconfigure urllist

To push multiple URL to use CPAN :

conf urllist push url1 url2 url3

To remove first in urllist :

conf urllist shift

To remove last in urllist :

conf urllist pop

To commit your changes :

conf commit

happy programming.

POST a Multipart request in Perl via LWP

Today I wrote good script which called the 3rd party API and for that I need to send a wav file via multipart.
I worte the code in Perl, which read my keyword via (param) and then I call my API and send the file via multipart.

#!/usr/bin/perl
print "Content-type: text/html\n\n";

use HTTP::Request::Common;
use LWP::UserAgent;
use CGI qw(:standard);
use strict;
use warnings;

my $file, $result, $message;
my $filePath = '/srv/www/cgi-bin/files';

$file = $filePath.'/'.$keyword.".wav";

my $ua = LWP::UserAgent->new;
my $req = $ua->request(POST 'http://www.yourURL',
	      Content_Type => 'form-data',
	      Content => [
		foo => "$foo",
		bar => "$bar",
		Upload => ["$file"]
	      ]
);

print "\nRESPONSE -- \n" . $req->as_string;

# Check the outcome of the response
if ($req->is_success) {
    print $req->content;
}
else {
  print "\n in else not success\n";
}

More links to read :
http://www.perlmonks.org/index.pl?node_id=186591
http://search.cpan.org/~gaas/libwww-perl/lib/HTTP/Request/Common.pm

Happy Programming.